U.S. patent application number 16/321039 was filed with the patent office on 2019-05-30 for ceiling repair method and wall repair method.
The applicant listed for this patent is KOGAKUIN UNIVERSITY. Invention is credited to Osamu GOTO, Koreyuki ISHIZAKI, Hiroaki MARUYAMA, Masaki TAMURA, Junichi YOKOSHIMA.
Application Number | 20190161984 16/321039 |
Document ID | / |
Family ID | 61016967 |
Filed Date | 2019-05-30 |
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United States Patent
Application |
20190161984 |
Kind Code |
A1 |
GOTO; Osamu ; et
al. |
May 30, 2019 |
CEILING REPAIR METHOD AND WALL REPAIR METHOD
Abstract
The present invention provides a method of repairing a plaster
ceiling. The plaster ceiling to be repaired by the above described
method includes: plates bridged across joists and spaced apart from
each other; a ceiling base material finished with a masonry trowel
over the lower surfaces of the plates; and a ceiling finishing
material formed over the lower surface of the ceiling base
material. The above described method includes the steps of:
drilling an injection hole extending from the upper surface of the
plate to the interface between the plate and the ceiling base
material; injecting an acrylic resin composition containing: at
least one monomer selected from an acrylic monomer or an
methacrylic monomer; a thermosetting resin; and a curing agent;
through the injection hole into the interface between the plate and
the ceiling base material; and curing the acrylic resin composition
so that the plate and the ceiling base material are adhered to each
other. The invention also provides the use of the above described
method.
Inventors: |
GOTO; Osamu; (Shinjuku-ku,
Tokyo, JP) ; TAMURA; Masaki; (Shinjuku-ku, Tokyo,
JP) ; MARUYAMA; Hiroaki; (Shinagawa-ku, Tokyo,
JP) ; YOKOSHIMA; Junichi; (Yotukaido-shi, Chiba,
JP) ; ISHIZAKI; Koreyuki; (Chiba-shi, Chiba,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KOGAKUIN UNIVERSITY |
Shinjuku-ku, Tokyo |
|
JP |
|
|
Family ID: |
61016967 |
Appl. No.: |
16/321039 |
Filed: |
July 27, 2017 |
PCT Filed: |
July 27, 2017 |
PCT NO: |
PCT/JP2017/027341 |
371 Date: |
January 28, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C04B 2111/72 20130101;
C04B 26/06 20130101; C04B 2111/00663 20130101; E04G 23/02 20130101;
C04B 41/60 20130101; C04B 2111/00637 20130101; E04G 23/0211
20130101; E04G 23/0207 20130101; E04G 23/0214 20130101 |
International
Class: |
E04G 23/02 20060101
E04G023/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 29, 2016 |
JP |
2016-150662 |
Claims
1-3. (canceled)
4. A method of repairing a plaster ceiling having plates bridged
across joists and spaced apart from each other, a wire mesh
provided so as to extend across the plates, and a ceiling finishing
material formed over a lower surface of the wire mesh, the method
comprising: applying an acrylic resin composition containing at
least one monomer selected from the group consisting of an acrylic
monomer and a methacrylic monomer, a thermosetting resin, and a
curing agent, to the wire mesh from an upper side to introduce the
acrylic resin composition into an interface between the wire mesh
and the ceiling finishing material; and adhering the wire mesh and
the ceiling finishing material by curing the acrylic resin
composition.
5. The method of repairing a plaster ceiling according to claim 4,
further comprising providing a new wire mesh so as to extend across
upper surfaces of the plates, wherein adhering the wire mesh and
the ceiling finishing material includes adhering the new wire mesh,
the wire mesh provided so as to extend across the plates and the
ceiling finishing material by curing the acrylic resin
composition.
6. A method of repairing a plaster wall, the method comprising:
drilling an injection hole at a site of the plaster wall to be
repaired, which has: a base material; an intermediate coating
material applied with a masonry trowel on the base material; and a
surface material applied with a masonry trowel on the intermediate
coating material, wherein the injection hole is extended from the
base material through the intermediate coating material to an
interface between the intermediate coating material and the surface
material; injecting an acrylic resin composition containing at
least one monomer selected from the group consisting of an acrylic
monomer and a methacrylic monomer, a thermosetting resin, and a
curing agent, into the interface between the intermediate coating
material and the surface material; and adhering the interface
between the intermediate coating material and the surface material
by curing the acrylic resin composition.
7. A method of repairing a plaster ceiling having plates bridged
across joists and spaced apart from each other, a ceiling base
material applied to a surface formed from the plates with a masonry
trowel from a bottom side, and a ceiling finishing material formed
over a lower surface of the ceiling base material, the method
comprising: the following (i), (ii) or (iii), (i) drilling an
injection hole extending from an upper surface of one of the plates
to an interface between the one of the plate and the ceiling base
material, (ii) drilling an injection hole extending from an upper
surface of one of the plates to an interface between the ceiling
base material and the ceiling finishing material, (iii) the ceiling
base material has a penetrating portion extending from a lower
surface of one of the plates through a gap between a plurality of
the plates up to an upper surface of the one of the plates, and a
ceiling finishing material formed over a lower surface of the
ceiling base material; and the following (iv), (v) or (vi), (iv)
injecting an acrylic resin composition containing at least one
monomer selected from the group consisting of an acrylic monomer
and a methacrylic monomer, a thermosetting resin, and a curing
agent, through the injection hole into the interface between the
one of the plates and the ceiling base material, (v) injecting an
acrylic resin composition containing at least one monomer selected
from the group consisting of an acrylic monomer and a methacrylic
monomer, a thermosetting resin, and a curing agent, through the
injection hole into the interface between the ceiling base material
and the ceiling finishing material, (vi) injecting an acrylic resin
composition containing at least one monomer selected from the group
consisting of an acrylic monomer and a methacrylic monomer, a
thermosetting resin, and a curing agent, into an interface between
the one of the plates and the ceiling base material, through a gap
between a side face of the one of the plates and the ceiling base
material that is stuffed in the gap between a plurality of the
plates up to an upper surface of the plate; and the following (vii)
or (viii), (vii) adhering the one of the plates and the ceiling
base material by curing the acrylic resin composition, (viii)
adhering the ceiling base material and the ceiling finishing
material by curing the acrylic resin composition.
8. The method of repairing a plaster ceiling according to claim 7,
wherein the method comprises (i), (iv) and (vii).
9. The method of repairing a plaster ceiling according to claim 7,
wherein the method comprises (ii), (v) and (viii).
10. The method of repairing a plaster ceiling according to claim 7,
wherein the method comprises (iii), (vi) and (vii).
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a method of repairing a
ceiling and a method of repairing a wall, which ceiling or wall is
formed with a trowel finish and includes a finishing material layer
on a surface thereof.
BACKGROUND ART
[0002] Traditional Japanese architecture often includes ceilings,
walls and the like which are formed with a trowel finish using
plaster, etc. A trowel-finished wall usually has a structure in
which a base material, an intermediate coating material, and a
surface material are formed in this order. Specifically, in
general, a so-called "Komaishitaji", which is a base material
formed by knitting bamboo strips or the like in the form of a
lattice, is used as the base material of the wall. On one surface
or both surfaces of the "Komaishitaji", clay, earth, or optionally,
a mixture obtained by mixing into earth or clay, material(s)
selected from the group consisting of straw, hemp fibers, "funori"
(a glue used in Japan as a size for textiles), and slaked lime,
etc., is applied in layers and finished with a masonry trowel, to
form the intermediate coating material. Then plaster containing
slaked lime and the like is applied in layers and finished with a
masonry trowel, to form the surface material, thereby finishing the
surface of the wall. The surface material is also referred to as a
top coat material.
[0003] Plaster used in the surface material has an excellent water
resistance, and is white and excellent in appearance. Thus, plaster
has long been used widely as a surface material, particularly as a
finishing material for walls, ceilings and the like.
[0004] Further, plaster is excellent in workability. Therefore,
after forming a base material using plaster, namely, forming an
under layer made of plaster, in a ceiling, a wall, or the like,
plaster is further used as a finishing material, to provide a
surface decoration. Examples of the surface decoration formed using
plaster include: a decoration having surface irregularities, such
as a relief sculpture formed with plaster; and a decoration in
which a fresco painting is provided, formed by applying plaster as
a finishing material, and painting a picture before the applied
plaster as the finishing material is dried. In such a manner,
plaster is used to provide a decoration on the surface of a
ceiling, a wall, a pillar or the like, in a variety of forms.
[0005] However, the walls, ceilings and the like which are finished
with a masonry trowel using plaster have poor elasticity.
Therefore, damage may occur with the passage of time, as a result
of shrinkage due to temperature changes, application of external
stresses, such as earth quakes, and the like.
[0006] In Japan, many of western-style buildings which had been
built since around the Meiji period (from 1868 to 1912) include
decorative plaster ceilings, plaster walls and the like, in which
plates arranged spaced apart from each other are used as a base,
and plaster is used as a finishing material. A plate to be used as
a base of a plaster ceiling is sometimes referred to as a "wood
lath" in Japan.
[0007] In countries other than Japan, as well, there are many
buildings including plaster ceilings, plaster walls and the like,
in which the same or similar plates are used as a base, and plaster
is used as a finishing material to provide relief sculptures and/or
fresco paintings on the surfaces thereof.
[0008] For a case in which damage occurs in a building in which
surface decorations are provided using plaster, a technique is
needed which allows for repair and restoration of the building
without greatly impairing historical values and decorative
appearance thereof.
[0009] Conventionally, when deterioration or damage, such as,
surface delamination, a crack, a cross sectional defect or flaking,
occurs in a trowel-finished wall surface, for example, a plastering
material having the same quality as the original material used for
forming the flaking portion, namely, for example, clay, plaster,
mortar or the like, is used to carry out a repair or reinforcement,
in order to restore the wall to the same condition as that at the
time of construction.
[0010] However, in a case in which the wall surface is repaired
from the surface, difference in appearance, such as difference in
color, may occur between the repaired portion and a portion which
has not been repaired. As a result, the integrity of the wall
surface as a whole cannot be maintained, possibly impairing the
appearance.
[0011] In particular, in the case of a ceiling or wall surface in
which irregularities such as a relief sculpture are formed or in
which a fresco painting is provided, and when the ceiling or wall
surface itself is an important cultural property, the following
procedure has been done. Specifically, a site where deterioration
is observed is removed and stored, and a replica which has been
especially prepared to replace an original, genuine article is
disposed at the original site. Thus, the conservation at the site
of repair or restoration is difficult, in the present
circumstances.
[0012] Conventionally, a cement composition has been proposed, as a
repairing material which has a low cure shrinkage rate and which is
used for repairing a damaged portion formed with a plastering
material, etc. The above described cement composition contains:
cement; an acrylic copolymer re-emulsified resin powder, surface
coated with a water-soluble protective colloid of polyvinyl
alcohol; an expanding material; and a shrinkage reducing agent (see
Japanese Patent Application Laid-Open (JP-A) No. 2009-102216).
[0013] Further, as a method of repairing a mortar material, a
technique for constructing a mortar-finished structure has been
proposed, in which a mortar cured body is formed in a missing
portion in a wall or the like, and after planarizing the surface, a
polymer cement composition for waterproofing is used to cover the
hydraulic mortar cured body, to provide a coated waterproof
membrane (see JP-A No. 2010-18492).
[0014] Reinforcing a plaster ceiling is more difficult, because, in
the plaster ceiling, a damaged surface faces downward with respect
to the direction of gravity, and thus differs from the surface of a
trowel-finished wall having a vertical surface. Accordingly, in a
plaster ceiling, a filler such as mortar is used to repair a
portion at which a crack is observed at an external surface.
However, for a repair at a site with a risk of collapse, no coping
method has been found at present, except for performing a repairing
method such as: providing a plate or a net to a lower portion of
the plaster ceiling; or using screws to fix the ceiling. Such a
repairing method greatly impairs the appearance of a plaster
ceiling to be repaired, and no fundamental solution to achieve the
repair, reinforcement or the like of the plaster ceiling has been
found in the present circumstances.
[0015] The present inventors have previously done studies on a
method of repairing a ceiling or a wall using an acrylic resin
cured body of a specific acrylic resin composition, as a method
which allows for repairing a face, such as a ceiling or a wall, on
site, and while further reducing an impact on the appearance (see
Literature 1 "Tamura, et al., "Development of Maintenance and
Conservation Methods for Historical Architecture using plaster wall
materials, Part 4 ", PERORM, January, 2016, pp. 1-5").
SUMMARY OF INVENTION
Technical Problem
[0016] The composition disclosed in JP-A No. 2009-102216 is
intended mainly for use in a construct including a mortar material.
When the composition is used in a construct formed with a
plastering material, it is possible to repair the surface of the
construct, but an internal reinforcement cannot be provided.
Further, an effect of the composition to prevent shrinkage, as a
repairing material, is limited, and the problem that the difference
in appearance occurs between the repaired portion and the portion
before the repair has not yet been solved. Accordingly, it is
difficult to use the above described composition for the purpose of
repairing historical buildings and the like in which appearance is
important.
[0017] Further, the technique disclosed in JP-A No. 2010-18492 is a
technique intended for use in a construct formed with a mortar
material, and although the technique can be used for repairing
cracks on the surface of a wall body or the like, it requires the
application of a polymer cement composition on the surface.
Accordingly, as with the technique disclosed in JP-A No.
2009-102216, it is difficult use the above described technique for
repairing a face which is finished by conventional plastering, from
the viewpoint of appearance.
[0018] The method disclosed in the Literature 1 enables to markedly
reduce deterioration in appearance on the surface of a plaster wall
or the like. However, this method involves drilling an injection
hole, although small, on the surface of a wall, a ceiling or the
like to be repaired, and thus, there is room for an improvement,
from the viewpoint of maintaining the appearance in a more
favorable manner.
[0019] An object of one embodiment of the present invention is to
provide a method of repairing a ceiling, wherein the method allows
for repairing a portion having a reduced strength or the like, in a
ceiling which is formed with a trowel finish and which includes on
the surface thereof a finishing material layer formed with plaster,
while minimizing the impact on the appearance.
[0020] An object of another embodiment of the invention is to
provide a method of repairing a plaster wall, wherein the method
allows for repairing a portion having a reduced strength or the
like, in a wall which includes on the surface thereof a finishing
material layer formed with plaster, while minimizing the impact on
the appearance.
Solution to Problem
[0021] Means for solving the above described problems include the
following embodiments.
[0022] <1> A method of repairing a plaster ceiling having
plates bridged across joists and spaced apart from each other, a
ceiling base material applied to a surface formed from the plates
with a masonry trowel from a bottom side, and a ceiling finishing
material formed over a lower surface of the ceiling base material,
the method comprising:
[0023] drilling an injection hole extending from an upper surface
of one of the plates to an interface between the one of the plates
and the ceiling base material;
[0024] injecting an acrylic resin composition containing at least
one monomer selected from the group consisting of an acrylic
monomer and a methacrylic monomer, a thermosetting resin, and a
curing agent, through the injection hole into the interface between
the one of the plates and the ceiling base material; and
[0025] adhering the one of the plates and the ceiling base material
by curing the acrylic resin composition.
[0026] In the first embodiment, which is described above, a cured
body of the injected acrylic resin composition is formed between
one of the plates and the ceiling base material, at a repaired
site. The plates are structural materials in the ceiling, and the
ceiling base material serves as a substrate for the ceiling
finishing material having a decoration such as a relief sculpture.
The presence of the thus formed cured body of the acrylic resin
composition at the repaired site allows for a strong adhesion
between the plate and the ceiling base material, and effectively
prevents the collapse of the ceiling due to the delamination of the
plates and the ceiling base material from the ceiling.
[0027] Since the cured body of the acrylic resin composition is
present at the interface between the plate and the ceiling base
material at the repaired site, it is possible to repair the damage
in the ceiling and to provide reinforcement, without affecting a
decorative surface of the ceiling finishing material. Further, a
portion of the acrylic resin composition infiltrates into the
interior of the ceiling base material, and the cured body of the
acrylic resin which has infiltrated into the interior of the
ceiling base material and cured thereat, serves as an anchor,
thereby allowing for a stronger adhesion between the plates and the
ceiling base material.
[0028] <2> A method of repairing a plaster ceiling having
plates bridged across joists and spaced apart from each other, a
ceiling base material applied to a surface formed from the plates
with a masonry trowel from a bottom side, and a ceiling finishing
material formed over a lower surface of the ceiling base material,
the method comprising:
[0029] drilling an injection hole extending from an upper surface
of one of the plates to an interface between the ceiling base
material and the ceiling finishing material;
[0030] injecting an acrylic resin composition containing at least
one monomer selected from the group consisting of an acrylic
monomer and a methacrylic monomer, a thermosetting resin, and a
curing agent, through the injection hole into the interface between
the ceiling base material and the ceiling finishing material;
and
[0031] adhering the ceiling base material and the ceiling finishing
material by curing the acrylic resin composition.
[0032] In the second embodiment, which is described above, a cured
body of the injected acrylic resin composition is formed at the
interface between the ceiling base material and the ceiling
finishing material. The ceiling base material is formed in close
contact with the plates, which are structural materials in the
ceiling, and includes penetrating portions extending through gaps
between a plurality of the plates up to the upper surfaces of the
plates; and the ceiling finishing material includes a decoration
such as a relief sculpture. The presence of the cured body of the
acrylic resin composition at the interface allows for a strong
adhesion between the ceiling base material and the ceiling
finishing material. Further, a portion of the acrylic resin
composition infiltrates from the interface between the ceiling base
material and the ceiling finishing material, into the interior of
the ceiling base material and of the ceiling finishing material, to
be cured thereat. The thus formed cured body of the acrylic resin
composition provides an anchoring effect, thereby allowing for a
stronger adhesion between the ceiling base material and the ceiling
finishing material. Since the ceiling base material includes the
penetrating portions extending up to the upper surfaces of the
plates, as described above, the method according to the second
embodiment enables to effectively prevent the collapse of the
ceiling base material and the ceiling finishing material from the
ceiling.
[0033] Although the cured body of the acrylic resin composition is
formed in a state where the composition has partially infiltrated
into the ceiling finishing material from the interface with the
ceiling base material, there is no possibility that the acrylic
resin composition infiltrates into the ceiling finishing material
as deep as to cause a potential damage to the appearance of the
surface of the ceiling finishing material. This is because the
finishing material is formed such that the density of the material
increases as it gets to closer to the surface. Accordingly, there
is no risk that the cured body of the acrylic resin composition
affects the decorative surface provided to the ceiling finishing
material.
[0034] <3> A method of repairing a plaster ceiling having
plates bridged across joists and spaced apart from each other, a
ceiling base material applied to a surface formed from the plates
with a masonry trowel from a bottom side and having a penetrating
portion extending from a lower surface of one of the plates through
a gap between a plurality of the plates up to an upper surface of
the one of the plates, and a ceiling finishing material formed over
a lower surface of the ceiling base material, the method
comprising:
[0035] injecting an acrylic resin composition containing at least
one monomer selected from the group consisting of an acrylic
monomer and a methacrylic monomer, a thermosetting resin, and a
curing agent, into an interface between the one of the plates and
the ceiling base material, through a gap between a side face of the
one of the plates and the ceiling base material that is stuffed in
the gap between a plurality of the plates up to an upper surface of
the plate; and
[0036] adhering the one of the plates and the ceiling base material
by curing the acrylic resin composition.
[0037] The third embodiment, which is described above, can be
referred to as a modification of the previously described first
embodiment. In the present embodiment, cured bodies of the injected
acrylic resin composition are formed between the plates, which are
structural materials in the ceiling, and the ceiling base material,
which serve as a substrate for the ceiling finishing material
having a decoration such as a relief sculpture. The presence of the
cured bodies of the acrylic resin allows for a strong adhesion
between the plates and the ceiling base material, and effectively
prevents the collapse of the ceiling due to the delamination of the
plates and the ceiling base material from the ceiling. The above
described effect is the same as that provided by the method
according to the first embodiment.
[0038] In the present embodiment, the acrylic resin composition is
injected through the gaps between the ceiling base material
extending up to the upper surfaces of the plates and the side
surfaces of plates, without forming an injection hole in one of the
plates. By injecting the acrylic resin composition through the gaps
which have been formed between the ceiling base material and the
side surfaces of the plates, as a result of slight shrinkage of the
ceiling base material due to the passage of time, the cured bodies
of the acrylic resin composition are formed also between the side
surfaces of the plates and the ceiling base material. Thus, the
gaps formed between the plates and the ceiling base material are
also filled with the cured bodies of the acrylic resin composition.
Further, since there is no need to provide an injection hole in the
plate and the ceiling base material, in the present embodiment, it
is possible to allow for a stronger adhesion between the plates and
the ceiling base material, including the regions of the gaps formed
between the side surfaces of the plates and the ceiling base
material, by a simpler means.
[0039] <4> A method of repairing a plaster ceiling having
plates bridged across joists and spaced apart from each other, a
wire mesh provided so as to extend across the plates, and a ceiling
finishing material formed over a lower surface of the wire mesh,
the method comprising:
[0040] applying an acrylic resin composition containing at least
one monomer selected from the group consisting of an acrylic
monomer and a methacrylic monomer, a thermosetting resin, and a
curing agent, to the wire mesh from an upper side to introduce the
acrylic resin composition into an interface between the wire mesh
and the ceiling finishing material; and
[0041] adhering the wire mesh and the ceiling finishing material by
curing the acrylic resin composition.
[0042] The fourth embodiment, which is described above, is an
effective method of repairing a plaster ceiling including a wire
mesh reinforcing material referred to as "lath". Such type of
ceilings had been frequently formed in Japan around Meiji period.
The "lath" is sometimes used to collectively refer to materials
used as a base, in plaster ceilings and the like. The "lath" as
used in the present specification refers to a wire mesh, which is a
so-called "metal lath", used as a base reinforcing material in a
plaster ceiling, a plaster wall, or the like.
[0043] The ceiling to be repaired by the method of the present
embodiment includes: plates bridged across joists and spaced apart
from each other; and a wire mesh provided so as to extend across
the plates. Although the wire mesh is effective as a reinforcing
material, there is a risk that wire mesh may corrode under the
influence of moisture and the like, with the passage of time; in
other words, there is a risk that the strength of the wire mesh may
be decreased due to development of rust in the wire mesh.
[0044] In the present embodiment, the acrylic resin composition is
applied on the upper surface of the wire mesh. The wire mesh has
large pores, and thus, the applied acrylic resin composition is
introduced into the interface between the wire mesh and the ceiling
finishing material. When the acrylic resin composition is cured in
that state, the resulting cured bodies of the acrylic resin
composition include portions of the wire mesh therein, and are in
contact with the ceiling finishing material. The presence of the
cured bodies improves the adhesion between the wire mesh having a
risk of a reduced strength and the ceiling finishing material, and
effectively prevents the collapse of the ceiling due to the
delamination between the wire mesh and the ceiling finishing
material. Further, since the resulting cured bodies include therein
the wire mesh having a reduced strength, the cured bodies of the
acrylic resin composition themselves function as reinforcing
materials. As a result, a situation in which the plaster ceiling
collapses along with the wire mesh can also be prevented.
[0045] In addition, since the cured bodies of the acrylic resin
composition are formed at the upper surface of the ceiling
finishing material, in the present embodiment, the ceiling in which
the wire mesh is deteriorated due to corrosion can be repaired,
without a potential risk of affecting the decorative surface which
is formed at the lower surface of the ceiling finishing material
having a decoration.
[0046] It is to be noted, in the present specification, that a
phenomenon in which a wire mesh develops rust on at least a portion
thereof under the influence of moisture, acidic substances, and the
like, or a metal structure of the wire mesh is damaged, etc., to
result in a decrease in the strength of the wire mesh, is
hereinafter sometimes referred to as "corrosion of a wire
mesh".
[0047] <5> A method of repairing a plaster ceiling having
plates bridged across joists and spaced apart from each other, a
wire mesh provided so as to extend across the plates, and a ceiling
finishing material formed over a lower surface of the wire mesh,
the method comprising:
[0048] providing a new wire mesh so as to extend across upper
surfaces of the plates;
[0049] applying an acrylic resin composition containing at least
one monomer selected from the group consisting of an acrylic
monomer and a methacrylic monomer, a thermosetting resin, and a
curing agent, to an upper surface of the new wire mesh; and
[0050] adhering the new wire mesh, the wire mesh provided so as to
extend across upper surfaces of the plates and the ceiling
finishing material by curing the acrylic resin composition.
[0051] The fifth embodiment, which is described above, is also an
effective method of repairing a plaster ceiling including a wire
mesh reinforcing material referred to as "lath".
[0052] The ceiling to be repaired by the method of the present
embodiment includes: plates bridged across joists and spaced apart
from each other; and a wire mesh provided so as to extend across
the plates. Although the wire mesh is effective as a reinforcing
material, there is a risk that wire mesh may corrode under the
influence of moisture and the like, with the passage of time,
resulting in a decrease in the strength of the wire mesh.
[0053] The present embodiment includes the step of providing a new
wire mesh so as to extend across the upper surfaces of the plates,
in addition to the previously provided wire mesh. In general, the
previously provided wire mesh is fixed to the plates from the lower
surfaces of the plates. As a result of providing the new wire mesh
so as to extend across the upper surfaces of the plates, a new
reinforcing material having a high strength is additionally
provided. When the acrylic resin composition is applied over the
upper surface of the newly provided wire mesh, the applied acrylic
resin composition passes through the pores of the newly provided
wire mesh and the previously provided wire mesh, and is introduced
into the interface between the previously provided wire mesh and
the ceiling finishing material. By adjusting the amount to be
applied of the acrylic resin composition, it is possible to allow
the resulting cured bodies of the acrylic resin composition to
include portions of the newly provided wire mesh and the previously
provided wire mesh therein, and to be in contact with the ceiling
finishing material.
[0054] As a result, respective components in a structure composed
of the previously provided wire mesh having a risk of a reduced
strength and the ceiling finishing material, further reinforced
with the newly provided wire mesh, are adhered by the cured bodies
of the acrylic resin composition. By including the newly provided
wire mesh in the cured bodies, the collapse of the ceiling due to
the delamination between the previously provided wire mesh and the
ceiling finishing material can be further effectively prevented.
Further, at the regions where the newly provided wire mesh is in
contact with previously provided wire mesh and the ceiling
finishing material, the newly provided wire mesh is present within
the interior of the cured bodies of the acrylic resin composition,
and thus less prone to be affected by moisture in the air and the
like. Therefore, a situation in which the plaster ceiling collapses
along with the wire mesh can also be prevented over a longer period
of time.
[0055] Since the cured bodies of the acrylic resin composition are
formed at the upper surface of the ceiling finishing material, in
the present embodiment, as with the previously described fourth
embodiment, it is possible to repair the ceiling in which the wire
mesh is deteriorated, without a potential risk that the cured
bodies of the acrylic resin composition affect the decorative
surface which is formed at the lower surface of the ceiling
finishing material having a decoration.
[0056] <6> A method of repairing a plaster wall, the method
comprising:
[0057] drilling an injection hole at a site of the plaster wall to
be repaired, which has: a base material; an intermediate coating
material applied with a masonry trowel on the base material; and a
surface material applied with a masonry trowel on the intermediate
coating material, wherein the injection hole is extended from the
base material through the intermediate coating material to an
interface between the intermediate coating material and the surface
material;
[0058] injecting an acrylic resin composition containing at least
one monomer selected from the group consisting of an acrylic
monomer and a methacrylic monomer, a thermosetting resin, and a
curing agent, into the interface between the intermediate coating
material and the surface material; and
[0059] adhering the interface between the intermediate coating
material and the surface material by curing the acrylic resin
composition.
[0060] The sixth embodiment, which is described above, relates to a
method of repairing a wall (plaster wall) including a surface
material having a decoration formed with plaster.
[0061] In the present embodiment, the injection hole for injecting
the acrylic resin composition is formed from the side of the wall
opposite to the surface material. In the present embodiment, it is
preferable to detect the portion of the interface which needs to be
repaired, more specifically, the portion of the interface between
the intermediate coating material and the surface material at which
a gap has been formed, in advance, and to drill the injection hole
so as to extend to the detected portion of the interface. When the
acrylic resin composition is injected into the portion of the
interface at which the gap has been formed and an adhesion strength
is reduced, the acrylic resin composition is filled into the gap
and formed into a cured body of the acrylic resin composition
thereat. In this manner, it is possible to achieve both filling the
gap and improving the adhesion between the intermediate coating
material and the surface material at the interface therebetween, at
the same time.
[0062] In the present embodiment, the acrylic resin composition
infiltrates into a portion of the plaster constituting the
intermediate coating material and the surface material to exhibit
an anchoring effect, thereby enabling to provide a robust repair.
Further, there is no risk that the acrylic resin composition which
has infiltrated into the surface material from the side thereof in
contact with the intermediate coating material, infiltrates as far
as to reach the surface of the surface material provided with a
decoration. Therefore, it is possible to reinforce the plaster
wall, without a potential risk that the resulting cured body of the
acrylic resin composition affect the decoration provided on the
surface.
Advantageous Effects of Invention
[0063] One embodiment of the invention provides a method of
repairing a ceiling, wherein the method allows for repairing a
portion having a reduced strength or the like, in a ceiling which
is formed with a trowel finish and which includes on the surface
thereof a finishing material layer formed with plaster, while
minimizing the impact on the appearance. Another embodiment of the
invention provides a method of repairing a plaster wall, wherein
the method allows for repairing a portion having a reduced strength
or the like, in a wall which includes on the surface thereof a
finishing material layer formed with plaster, while minimizing the
impact on the appearance.
BRIEF DESCRIPTION OF DRAWINGS
[0064] FIG. 1 is a schematic sectional view showing a portion of
one embodiment of a ceiling which has been repaired by the method
according to the first embodiment, and which includes a cured body
of an acrylic resin composition formed at the interface between a
plate and a ceiling base material.
[0065] FIG. 2 is a schematic sectional view showing a portion of
one embodiment of a ceiling which has been repaired by the method
according to the second embodiment, and which includes a cured body
of the acrylic resin composition formed at the interface between
the ceiling base material and a ceiling finishing material.
[0066] FIG. 3 is a schematic sectional view showing a portion of
one embodiment of a ceiling which has been repaired by the method
according to the third embodiment, and which includes cured bodies
of the acrylic resin composition formed at the interface between
the plates and the ceiling base material, and between the side
surfaces of the plates and the ceiling base material.
[0067] FIG. 4A is a schematic sectional view showing a portion of
one embodiment of a ceiling which has been repaired by the method
according to the fourth embodiment, and which includes cured bodies
of the acrylic resin composition formed to include the regions of a
wire mesh.
[0068] FIG. 4B is a plan view showing a portion of one embodiment
of the wire mesh used in the fourth embodiment.
[0069] FIG. 5 is a schematic sectional view showing a portion of
one embodiment of a ceiling which has been repaired by the method
according to the fifth embodiment, and which includes cured bodies
of the acrylic resin composition formed to include the regions of a
newly provided wire mesh and the previously provided wire mesh.
[0070] FIG. 6 is a schematic sectional view showing a portion of
one embodiment of a wall which has been repaired by the method
according to the sixth embodiment, and which includes a cured body
of the acrylic resin composition formed at the interface between a
base material and a finishing material.
DESCRIPTION OF EMBODIMENTS
[0071] First, the methods of repairing a ceiling according to the
embodiments of the present invention will be described with
reference to drawings.
[0072] In each of the drawings, the same reference numerals are
used to refer to the same components.
[0073] In the present specification, the definition of a "wall or
ceiling finished with a masonry trowel" or a "wall or ceiling
formed with a trowel finish" encompasses any structure finished by
hand using a masonry trowel, such as an earthen wall, a plaster
wall, a mortar wall, a plaster ceiling, a mortar ceiling, or the
like.
[0074] A masonry trowel is a tool used for applying plaster or the
like, or planarizing the surface applied therewith for finishing.
In general, a masonry trowel has a form in which a wooden handle is
attached to a metal plate, such as an iron plate. The expression
"to form with a `trowel finish`" or to "finish with a masonry
trowel" refers to planarizing, or to providing a decoration having
irregularities on, the surface of a surface material containing
plaster, mortar or the like, using a masonry trowel.
[0075] Further, in the present specification, the definition of the
term "ceiling finishing material" or "surface material" of a wall
encompasses any surface material to be provided to a ceiling or a
wall, which has a surface on which a three dimensional decoration
such as a relief sculpture is formed with plaster, or a plaster
surface on which a painting, a pattern or the like is provided.
Method of Repairing Ceiling According to First Embodiment
[0076] FIG. 1 is a schematic sectional view showing a portion of
one embodiment of a plaster ceiling 10 (hereinafter, sometimes
referred to as a ceiling 10) which has been repaired by the method
of repairing a ceiling according to the first embodiment, and which
includes a cured body 15 of an acrylic resin composition formed at
the interface between one of plates 11 and a ceiling base material
12.
[0077] The method of repairing a plaster ceiling according to the
first embodiment is a method of repairing the plaster ceiling 10,
which includes: the plates 11 bridged across joists and spaced
apart from each other; the ceiling base material 12 finished with a
masonry trowel over the lower surfaces of the plates 11; and a
ceiling finishing material 13 formed over the lower surface of the
ceiling base material 12.
[0078] First, an injection hole 14 which extends from the upper
surface of the plate 11 to the interface between the plate 11 and
the ceiling base material 12 is drilled. Subsequently, the acrylic
resin composition is injected through the injection hole 14 into
the interface between the plate 11 and the ceiling base material
12.
[0079] The thus injected acrylic resin composition is cured to form
the cured body 15 of the acrylic resin composition, so that the
plate 11 and the ceiling base material 12 are adhered to each other
via the cured body 15.
[0080] When drilling the injection hole, it is preferred to detect
the portion of the interface at which a gap has been formed, in
advance, and to determine a drilling depth of the injection hole,
accordingly.
[0081] The portion of the interface at which a gap has been formed
can be detected, for example, by: a method in which preliminary
drilling is carried out at a site to be repaired; a method in which
a tapping rod such as one used for detecting the delamination of
tiles and the like is used to determine the portion at which
floating of the base material has occurred, namely, the portion at
which a gap has been formed, based on the dullness of a sound in
response to the tapping; or a method in which the portion at which
floating has occurred is detected based on the degree of decrease
in rebound velocity ratio which is measured as the ratio of a
reflected wave to an incident wave by a tapping sound.
[0082] By detecting the position of the interface at which a gap
has been formed, in advance, according to the previously described
method, and inserting a needle into the gap portion between the
base material and plaster, it is possible to measure the thickness
of the base material, and to determine the drilling depth of the
injection hole.
[0083] The detection of the portion of the interface at which a gap
has been formed in advance enables to carry out an efficient
repair.
[0084] Since the shrinkage rate due to changes in temperature and
humidity differs between the plates 11, and the ceiling base
material 12 which is formed with a trowel finish using plaster or
the like, an embodiment is also preferred in which the acrylic
resin composition is injected into the interface between the plates
11 and the ceiling base material 12, first, so as to fill the
acrylic resin composition into gaps formed due to the difference in
the shrinkage rate.
[0085] The acrylic resin composition injected into the injection
hole 14 flows through the injection hole 14 to reach the gap
between the plate 11 and the ceiling base material 12, and fills
the gap space. Thereafter, a portion of the acrylic resin
composition infiltrates into voids between plaster particles
included in the ceiling base material 12. Subsequently, the
infiltrated acrylic resin composition is cured to form the cured
body 15 of the acrylic resin composition.
[0086] The thus formed cured body 15 of the acrylic resin
composition enables the adhesion between the plate 11 and the
ceiling base material 12 at the interface therebetween, and serves
as an anchor to the ceiling base material 12. This allows for a
strong adhesion between the plates 11 and the ceiling base material
12, and prevents the delamination of the ceiling 10, particularly,
the collapse of the ceiling 10 which occurs as a result of the
ceiling base material 12 and the ceiling finishing material 13
delaminated and falls off from the plates 11.
[0087] (Step of Drilling Injection Hole)
[0088] The drilling of the injection hole 14 can be carried out by
an ordinary method. In the case of drilling the injection hole to
one of the plates 11, it is possible to use a known drilling
method, such as a method using a drill.
[0089] The drill to be used for drilling is preferably a rotary
drill whose number of revolution can be controlled depending on the
strength of the material to be drilled, such as the plates 11, and
the ceiling base material 12 to be described later, namely, a
resistance during the drilling. By means, such as using the rotary
drill whose number of revolution can be controlled, it is possible
to prevent the adhesion of components around the injection hole 14
to be formed by the drilling, thereby enabling to carry out the
drilling without damaging the ceiling base material, ceiling
finishing material and the like.
[0090] After the formation of the injection hole 14, it is
preferred to properly clean the interior of the injection hole 14
to remove machining chips, machining powder and the like generated
inside the injection hole 14 during the drilling, from the
viewpoint of improving the infiltrability of the acrylic resin
composition. The interior of the injection hole 14 can be cleaned
using a simple air dropper, by a method of blowing off the
machining chips or machining powder, or the like.
[0091] By adjusting the drilling depth of the injection hole 14, it
is possible to determine the site to be repaired. In the first
embodiment, the injection hole 14 is formed to a depth sufficient
to penetrate the plate 11.
[0092] When the depth of the injection hole 14 is adjusted to a
depth sufficient to penetrate the plate 11, it is possible to allow
the acrylic resin composition to infiltrate into the gap between
the plate 11 and the ceiling base material 12, and to firmly fix
the plate 11 and the ceiling base material 12 to each other, by the
cured body 15 of the acrylic resin composition formed by curing the
infiltrated composition.
[0093] After allowing the acrylic resin composition to infiltrate
into the gap formed at the interface between the plate 11 and the
ceiling base material 12, through the injection hole 14, the
acrylic resin composition is cured to form the cured body 15.
[0094] The acrylic resin composition usually cures in a curing time
of about one hour to two hours, and the composition quickly cures
to form the cured body 15 of the acrylic resin composition. The
curing time can be adjusted from about 30 minutes to seven days,
depending on the type and the amount to be added of a curing agent,
a delaying agent and the like contained in the acrylic resin
composition.
[0095] (Acrylic Resin Composition)
[0096] The acrylic resin composition to be used for forming a cured
body of the acrylic resin composition in the repairing method
according to the present disclosure is preferably an acrylic resin
composition containing one or more monomers selected from the group
consisting of acrylic monomers and methacrylic monomers, from the
viewpoint of infiltrability.
[0097] In the present specification, the term "(meth)acrylic" is
sometimes used to refer to either or both of "acrylic" and/or
"methacrylic", and the term "(meth)acrylate" is sometimes used to
refer to either or both of "acrylate" and/or "methacrylate".
[0098] Examples of a preferred acrylic resin composition to be used
in the repairing method according to the present disclosure include
an acrylic resin composition containing a (meth)acrylic monomer, a
thermosetting resin, and a curing agent.
[0099] The acrylic resin composition preferably has a viscosity at
normal temperature (25.degree. C.) within a range of from 80 mPas
to 100 mPas, from the viewpoint of achieving a favorable
infiltrability into the ceiling base material 12 and the ceiling
finishing material 13. The viscosity of the acrylic resin
composition can be measured by a method in accordance with JIS
K6833-1 (2008) at normal temperature (25.degree. C.), using a
Type-B viscosity meter.
[0100] When the acrylic resin composition has a viscosity within
the above described range, the acrylic resin quickly infiltrates
into a gap between the plate 11 and the ceiling base material 12, a
gap between the ceiling base material 12 and the ceiling finishing
material 13, etc. Further, a portion of the acrylic resin
composition naturally infiltrates into the interior of the ceiling
base material 12, the ceiling finishing material 13, etc., for
example, into the voids between clay particles, fine cracks having
a size of about 0.05 mm, and the like, under the condition of
atmospheric pressure.
[0101] It is preferred that the acrylic resin composition contains,
as an acrylic monomer which is a main component of the composition,
at least one selected from an acrylate monomer or a methacrylate
monomer. The (meth)acrylic monomer may be modified.
[0102] Preferred examples of the (meth)acrylic monomer include
dicyclopentenyloxyethylene methacrylate, and methoxypolyethylene
glycol #900 methacrylate.
[0103] It is also possible to use a commercially available product
of the (meth)acrylate monomer, and examples thereof include a
rebuilt resin, REBUILT 300 (brand name; dicyclopentenyloxyethylene
methacrylate, manufactured by Fukuda Jitsugyo Co., Ltd.), and
NK-ESTER M-20G (brand name; methoxypolyethylene glycol #900
methacrylate, manufactured by Shin Nakamura Chemical Co.,
Ltd.).
[0104] The content of the (meth)acrylic monomer with respect to the
total amount of the acrylic resin composition is preferably within
the range of from 80% by mass to 90% by mass, and more preferably
within the range of from 83% by mass to 88% by mass.
[0105] The acrylic resin composition may further contain
(meth)acrylic resin particles to the extent that a flowability of
the composition is not impaired.
[0106] The acrylic resin composition contains, in addition to the
(meth)acrylic monomer, a thermosetting resin which is useful for
forming a cured body having a high strength, and a curing agent
which allows the thermosetting resin to be cured.
[0107] Examples of the thermosetting resin include epoxy resins,
urethane resins, silicone resins, urea resins, and phenol
resins.
[0108] The content of the thermosetting resin with respect to the
total amount of the acrylic resin composition is preferably within
the range of from 10% by mass to 20% by mass, and more preferably
within the range of from 12% by mass to 16% by mass.
[0109] Preferred examples of the curing agent which allows the
thermosetting resin to be cured include organic peroxides such as
ketone peroxides, diacyl peroxides, dialkyl peroxides, and peroxy
esters.
[0110] The type and the content of the curing agent can be selected
as appropriate depending on the type and the content of the
thermosetting resin to be used.
[0111] The acrylic resin composition has a favorable flowability
even without containing a solvent, because the (meth)acrylic
monomer is in the form of a liquid. Therefore, the acrylic resin
composition has a lower volume shrinkage upon curing, as compared
to a resin composition obtained by dissolving a resin in a solvent,
and thus is preferably used in the repairing method according to
the present disclosure.
[0112] The acrylic resin composition may contain any of other
components as additives in order to adjust the flowability,
curability, and the like, to the extent that the effect of the
invention is not impaired.
[0113] Examples of the additive include: a chloroprene rubber as a
softening agent; inorganic particles as a viscosity modifier, such
as AEROSIL; an alkyl phenol as a delaying agent; and naphthene
cobalt as an accelerator.
[0114] A commercially available product may also be used as the
acrylic resin composition. Examples of the commercially available
product thereof include SHINTO JUST (brand name) manufactured by
Just Co., Ltd. There were cases in which SHINTO JUST was used as a
material for repairing cracks in a concrete cured body, or for
forming a rust preventive film for a metal; however, no case is
known in which SHINTO JUST was used in a method of repairing a
plaster ceiling or a plaster wall having a decoration, without
impairing the appearance thereof.
Method of Repairing Ceiling According to Second Embodiment
[0115] FIG. 2 is a schematic sectional view showing a portion of
one embodiment of a plaster ceiling 20 (hereinafter, sometimes
referred to as a ceiling 20) which has been repaired by the method
of repairing a ceiling according to the second embodiment, and
which includes a cured body 15 of the acrylic resin composition
formed at the interface between the ceiling base material 12 and
the ceiling finishing material 13.
[0116] As with the method of repairing a ceiling according to the
first embodiment, the method of repairing a plaster ceiling
according to the second embodiment is a method of repairing the
plaster ceiling 10, which includes: the plates 11 bridged across
joists and spaced apart from each other; the ceiling base material
12 finished with a masonry trowel over the lower surfaces of the
plates 11; and the ceiling finishing material 13 formed over the
lower surface of the ceiling base material 12.
[0117] In the second embodiment, an injection hole 14 is formed so
as to penetrate the plate 11 and the ceiling base material 12, and
the injection hole 14 is formed to a depth extending to the
interface between the ceiling base material 12 and the ceiling
finishing material 13.
[0118] When the depth of the injection hole 14 is adjusted to a
depth sufficient to penetrate the plate 11 and the ceiling base
material 12, it is possible to allow the acrylic resin composition
to infiltrate into the gap between the ceiling base material 12 and
the ceiling finishing material 13, and to firmly fix the ceiling
base material 12 and the ceiling finishing material 13 to each
other, by the cured body 15 of the acrylic resin composition, which
is a cured body of the infiltrated acrylic resin composition.
[0119] The method of forming the injection hole 14 is the same as
the method used in the previously described first embodiment.
[0120] The method according to the second embodiment allows for
effectively preventing the collapse of the ceiling base material 12
and the ceiling finishing material 13 from the ceiling 20. Further,
the cured body 15 of the acrylic resin composition is formed in a
state where the composition has partially infiltrated into the
ceiling base material 12 and the ceiling finishing material 13 from
the interface between the ceiling base material 12 and the ceiling
finishing material 13. This provides an anchoring effect which
allows for a strong adhesion between the ceiling base material 12
and the ceiling finishing material 13. Since the ceiling finishing
material 13 is usually formed so that the density of the material
increases as it gets closer to the surface, there is no possibility
that the acrylic resin composition infiltrates into the ceiling
finishing material 13 as deep as to cause a potential damage to the
appearance of the surface of the ceiling finishing material 13.
Therefore, there is no risk that the cured body of the acrylic
resin composition has an impact on the appearance of the decorative
surface provided to the ceiling finishing material 13.
[0121] The repairing method according to the second embodiment can
be carried out in the same manner as the repairing method according
to the first embodiment previously described, except that the
injection hole 14 is formed to a different drilling depth.
Repairing Method According to Third Embodiment
[0122] FIG. 3 is a schematic sectional view showing a portion of
one embodiment of a plaster ceiling 30 (hereinafter, sometimes
referred to as a ceiling 30) which has been repaired by the
repairing method according to the third embodiment, and which
includes cured bodies 15 of the acrylic resin composition formed at
the interface between the plates 11 and the ceiling base material
12, and between the side surfaces of the plates 11 and the ceiling
base material 12.
[0123] The present embodiment is a modification of the previously
described first embodiment.
[0124] In the present embodiment, the acrylic resin is injected
between the plates 11, which are structural materials in the
ceiling 30, and the ceiling base material 12, which serve as a
substrate for the ceiling finishing material 13 having a decoration
such as a relief sculpture, and cured to form the cured bodies 15
of the acrylic resin composition therebetween. The thus formed
cured bodies 15 allow for a strong adhesion between the plates 11
and the ceiling base material 12.
[0125] In the present embodiment, the acrylic resin composition is
injected through gaps A between the ceiling base material 12
extending up to the upper surfaces of the plates 11, and the side
surfaces of the plates 11, as shown in FIG. 3, without forming an
injection hole in one of the plates 11. By injecting the acrylic
resin composition through the gaps A, which have been formed
between the ceiling base material 12 and the side surfaces of the
plates 11 as a result of a slight shrinkage of the ceiling base
material 12, the cured bodies 15 of the acrylic resin composition
are formed also between the side surfaces of the plates 11 and the
ceiling base material 12. As a result, the gaps A formed between
the plates 11 and the ceiling base material 12 are also filled with
the cured bodies 15 of the acrylic resin composition.
[0126] Since there is no need to provide an injection hole in the
plate 11 and the ceiling base material 12, in the present
embodiment, it is possible to allow for a stronger adhesion between
the plates 11 and the ceiling base material 12, including the
regions of the gaps A formed at the side surfaces of the plates 11,
by a simpler means.
[0127] The repairing method according to the third embodiment can
be carried out in the same manner as the repairing method according
to the first embodiment previously described, except that the
injection hole 14 is not provided, and the acrylic resin
composition is injected into the gaps A formed between the side
surfaces of the plates 11 and the ceiling base material 12.
Repairing Method According to Fourth Embodiment
[0128] FIG. 4A is a schematic sectional view showing a portion of
one embodiment of a plaster ceiling (ceiling) 40, which has been
repaired by the repairing method according to the fourth
embodiment, and which includes cured bodies 15 of the acrylic resin
composition, formed to include the regions of a wire mesh 16 as a
reinforcing material. FIG. 4B is a plan view showing a portion of
one embodiment of the wire mesh 16 used in the fourth
embodiment.
[0129] The present embodiment is a method of repairing the plaster
ceiling 40 (hereinafter, sometimes referred to as a ceiling 40),
which includes plates 11 bridged across joists and spaced apart
from each other; the wire mesh 16 provided so as to extend across
the plates 11; and a ceiling finishing material 13 finished with a
masonry trowel over the lower surface of the wire mesh 16. The
present method is a method of repairing a plaster ceiling including
the steps of: applying the acrylic resin composition over the upper
surface of the wire mesh 16, so that the acrylic resin composition
is introduced into the interface between the wire mesh 16 and the
ceiling finishing material 13; and curing the acrylic resin
composition so that the wire mesh 16 and the ceiling finishing
material 13 are adhered to each other, by the cured bodies of the
acrylic resin composition.
[0130] The present embodiment is an effective method of repairing
the plaster ceiling 40 which includes the wire mesh 16 as a
reinforcing material.
[0131] As shown in FIG. 4A, the wire mesh 16 is usually fixed to
the lower surfaces of the plates 11.
[0132] The ceiling 40, which is a subject to be repaired by the
method of the present embodiment, includes the wire mesh 16
provided so as to extend across the plates 11. In the present
embodiment, the acrylic resin composition is applied over the upper
surface of the wire mesh 16. The wire mesh has large pores, and
thus, the applied acrylic resin composition is introduced into the
interface between the wire mesh 16 and the ceiling finishing
material 13. When the thus introduced acrylic resin composition is
cured, the cured bodies 15 of the acrylic resin composition, which
include portions of the wire mesh 16 and which are in contact with
the ceiling finishing material 13 over large areas, are formed over
a wide region.
[0133] Accordingly, the adhesion between the wire mesh 16 having a
risk of a reduced strength and the ceiling finishing material 13 is
improved, and the collapse of the ceiling 40 due to the
delamination between the wire mesh 16 and the ceiling finishing
material 13 is effectively prevented. Further, when the cured
bodies 15 including the wire mesh 16 having a reduced strength are
formed, the cured bodies 15 of the acrylic resin composition
themselves function as reinforcing materials. As a result, a
situation in which the plaster ceiling 40 collapses along with the
wire mesh 16 can be also prevented.
[0134] Since the cured bodies of the acrylic resin composition are
formed at the upper surface of the ceiling base material, in the
present embodiment, it is possible to repair the ceiling in which
the wire mesh is deteriorated, without a potential risk of
affecting the decorative surface which is formed at the lower
surface of the ceiling finishing material having a decoration.
Repairing Method According to Fifth Embodiment
[0135] FIG. 5 is a schematic sectional view showing a portion of
one embodiment of a plaster ceiling 50 (hereinafter, sometimes
referred to as a ceiling 50) which has been repaired by the
repairing method according to the fifth embodiment, and which
includes cured bodies 15 of the acrylic resin composition formed to
include the regions of a newly provided wire mesh 17 and the
previously provided wire mesh 16.
[0136] The above described fifth embodiment is also a method of
effectively repairing a plaster ceiling which includes, as with the
previously described fourth embodiment, the wire mesh 16 as a
reinforcing material referred to as "lath".
[0137] The ceiling 50, which is a subject to be repaired by the
method of the present embodiment, includes the plates 11 bridged
across joists and spaced apart from each other; and the wire mesh
16 provided so as to extend across the plates 11. The repairing
method of the present embodiment includes the step of providing the
new wire mesh 17 so as to extend across the upper surfaces of
plates 11, in addition to the previously provided wire mesh 16.
[0138] In general, the previously provided wire mesh 16 is fixed to
the plates 11 from the lower surfaces of the plates 11. By
providing the new wire mesh 17 so as to extend across the upper
surfaces of the plates 11, the wire mesh 17, which is a new
reinforcing material having a high strength, is additionally
provided. When the acrylic resin composition is applied over the
upper surface of the newly provided wire mesh 17, the applied
acrylic resin composition passes through the pores of the newly
provided wire mesh 17, and the previously provided wire mesh 16,
and is introduced into the interface between the previously
provided wire mesh 16 and the ceiling finishing material 13.
[0139] By adjusting the amount to be applied of the acrylic resin
composition, it is possible to allow the resulting cured bodies 15
of the acrylic resin composition to include portions of the newly
provided wire mesh 17 and the previously provided wire mesh 16
therein, and to be in contact with the ceiling finishing material
13. As a result, respective components in a structure composed of
the previously provided wire mesh 16 having a risk of a reduced
strength and the ceiling finishing material 13, further reinforced
with the newly provided wire mesh 17, are adhered by the cured
bodies 15 of the acrylic resin composition, thereby allowing for a
robust repair.
[0140] By forming the cured bodies 15 including the newly provided
wire mesh 17, the collapse of the ceiling due to the delamination
between the previously provided wire mesh 16 and the ceiling
finishing material 13 can be further effectively prevented.
Further, when the cured bodies 15 including the newly provided wire
mesh 17 are formed, the newly provided wire mesh 17 is present
within the interior of the cured bodies 15 of the acrylic resin
composition, at the regions where the wire mesh 17 is in contact
with the previously provided wire mesh 16 and the ceiling finishing
material 13. This makes the wire mesh 17 less prone to be affected
by moisture in the air and the like, thereby enabling to prevent a
situation in which the plaster ceiling 50 collapses, over a longer
period of time.
[0141] Since the cured bodies 15 of the acrylic resin composition
are formed at the upper surface of the ceiling finishing material
13, in the present embodiment, as with the previously described
fourth embodiment, there is no risk that the cured bodies 15 of the
acrylic resin composition affect the appearance of the decorative
surface which is formed at the lower surface of the ceiling
finishing material 13 having a decoration.
Repairing Method According to Sixth Embodiment
[0142] FIG. 6 is a schematic sectional view showing a portion of
one embodiment of a plaster wall 60 (hereinafter, sometimes
referred to as a wall 60) which has been repaired by the repairing
method according to the sixth embodiment, and which includes a
cured body 65 of the acrylic resin composition formed at the
interface between an intermediate coating material 62 and a
finishing material 63.
[0143] The present embodiment relates to a method of repairing the
wall 60 having a decoration. The wall 60 includes: a base material
61; the intermediate coating material 62 finished with a masonry
trowel on the base material 61; and the surface material 63
finished with a masonry trowel on the intermediate coating material
62. The present method is a method of repairing a plaster wall,
including the steps of: drilling an injection hole 64 extending to
the interface between the intermediate coating material 62 and the
surface material 63, to the site of the plaster wall 60 to be
repaired, from the side of the base material 61; injecting the
previously described acrylic resin composition through the
injection hole 64 into the interface between the intermediate
coating material 62 and the surface material 63; and curing the
acrylic resin composition to form the cured body 65 of the acrylic
resin composition, so that the intermediate coating material 62 and
the surface material 63 are adhered to each other at the interface
therebetween.
[0144] The method according to the sixth embodiment is suitable for
repairing the wall 60 including the surface material having a
decoration formed with plaster.
[0145] In the present embodiment, the injection hole 64 for
injecting the acrylic resin composition is formed from the side of
the wall 60 opposite to the surface material 63. In the present
embodiment, it is preferable to detect the portion of the interface
which needs to be repaired, more specifically, the portion of the
interface between the intermediate coating material 62 and the
surface material 63 at which a gap has been formed, in advance, and
to drill the injection hole 64 so as to extend to the detected
portion of the interface.
[0146] In order to detect the portion of the interface at which a
gap has been formed, it is possible to use the same method as the
method described in the first embodiment, for detecting a gap
formed at the interface in the ceiling.
[0147] When the acrylic resin composition is injected into the
portion of the interface between the intermediate coating material
62 and the surface material 63, at which a gap has been formed and
the adhesion strength is reduced, the acrylic resin composition is
filled into the interface, and formed into the cured body 65 of the
acrylic resin composition thereat. In this manner, it is possible
to achieve both filling the gap and improving the adhesion between
the intermediate coating material 62 and the surface material 63 at
the interface therebetween, at the same time.
[0148] In the present embodiment, the acrylic resin composition
infiltrates into a portion of the plaster constituting the
intermediate coating material 62 and the surface material 63 to
exhibit an anchoring effect, thereby enabling to provide a robust
repair. Further, since the surface material 63 is formed such that
the density of the material increases as it gets closer to the
decorative surface, there is no risk that the acrylic resin
composition which has infiltrated into the surface material 63 from
the side thereof in contact with the intermediate coating material
62, infiltrates as far as to reach the dense surface of the surface
material 63 provided with a decoration. Therefore, it is possible
to reinforce the wall 60 provided with a decoration, without
affecting the decoration provided on the surface.
EXAMPLES
[0149] The repairing methods according to the present disclosure
will now be described in detail, with reference to Examples.
However, each of the following Examples is merely one embodiment of
the repairing method according to the present disclosure, and the
present invention is in no way limited to these examples. Further,
a variety of modifications of the methods are possible.
(1) Example 1
[Preparation of Plaster Ceiling Material Test Specimens]
[0150] First, a ceiling for carrying out the repair according to
the present embodiment is prepared.
[0151] A wooden frame corresponding to a structure material was
formed, and four pieces of the plates 11 were bridged to extend in
one direction of the wooden frame, so as to be in parallel with and
spaced apart from each other, assuming that the wooden frame is a
joist.
[0152] The ceiling base material 12 was finished with a masonry
trowel over the lower surfaces of the plates 11. The plaster for
forming the ceiling base material 12 was provided so as to protrude
from between the adjacent plates 11 above the upper surfaces of the
plates 11. In this manner, biting portions of the ceiling base
material 12 protruding above the upper surfaces of the plates 11
were formed, as shown in FIG. 1. Then the ceiling finishing
material 13 was formed with a trowel finish over the lower surface
of the ceiling base material 12, and irregularities were formed on
the surface of the ceiling finishing material 13 with a masonry
trowel, as shown in FIG. 1, to provide a decorative surface.
[0153] The ceiling base material 12 and the ceiling finishing
material 13 were both formed with plaster. In this manner, each of
a plurality of test bodies was prepared.
[0154] The details of the plaster used in the formation of each
test body are shown below.
[0155] (Plaster Material Used for Forming Ceiling Base Material
12)
[0156] The materials used are tap water, slaked lime, straw fibers
for plastering (hereinafter, also simply referred to as "straw
fibers") treated to remove harshness, and the like.
[0157] As the plates 11, wood lath bases of rough cedar wood
(thickness: 12 mm, width 40: mm) were used.
[0158] The composition of the plaster for forming the ceiling base
material is such that the ratio of water and slaked lime was 85% by
mass, and the content of sand was 0% by mass.
[0159] The content of the straw fibers was adjusted to 0% by
volume, 2% by volume, or 4% by volume with respect to volume of the
test body.
[0160] The above described components were mixed, and water was
added to a total of 100% by mass, taking into account the mass of
the straw fibers corresponding to the above described volume, to
prepare a plaster material for forming the ceiling base material
12.
[0161] The "straw fibers" are a material obtained by cutting straw
such as rice straw into a size of about from 5 mm to 6 cm. The
straw fibers are mixed into plaster or the like, and used as a
reinforcing material or a filler. The "straw fibers treated to
remove harshness" (hereinafter, also simply referred to as
"lye-treated straw fibers") refer to straw fibers which have been
dipped in water or lye, followed by drying.
[0162] The "rough cedar wood" refers to a plate of cedar, obtained
by: removing the bark from a cedar log material, which is used as a
shaft material for use as a pillar or the like; and cutting into
strips peripheral end material portions, which are obtained after
cutting out a pillar material from the central portion of the log
material; which plate has not yet been subjected to surface
finishing with a plane or the like.
[0163] (Plaster Material Used for Forming Ceiling Finishing
Material 13)
[0164] The materials used are tap water, slaked lime, fine
aggregates for plastering (sand), lye-treated straw fibers, and the
like.
[0165] The composition of the plaster was such that the ratio of
water and slaked lime was 85% by mass, the content of sand was 20%
by mass, and the content of straw fibers was 0% by volume, 2% by
volume, or 4% by volume with respect to the volume of the test
body.
[0166] Thereafter, the above described components were mixed, in
the same manner as in the preparation of the plaster material used
for forming the ceiling base material 12, and water was added to a
total of 100% by mass, to prepare a plaster material for forming
the ceiling finishing material 13.
[0167] (Drilling of Injection Hole)
[0168] To one of the plates 11 in each resulting test body, the
injection hole 14 having a diameter of from 5 mm to 10 mm was
drilled using an electric drill.
[0169] The injection hole 14 was formed in a depth sufficient to
penetrate the plate 11 and to reach the ceiling base material 12. A
gap was experimentally formed between the plate 11 and the ceiling
base material 12.
[0170] (Injection of Acrylic Resin Composition and Preparation of
Cured Body of Acrylic Resin)
[0171] Into the thus drilled injection hole 14, an acrylic resin
composition [an infiltrative acrylic resin, SHINTO JUST (brand
name), manufactured by Just Co., Ltd.] was injected using a
syringe.
[0172] The acrylic resin composition was injected into the
injection hole 14 in such an amount that the interior of the
injection hole 14, and the gap formed between the plate 11 and the
ceiling base material 12 were both filled with the acrylic resin
composition.
[0173] The thus formed gap had local variations in thickness, which
were within the range of from more than 0 mm but equal to or less
than 2 mm.
[0174] The thickness of the gap in Example 1 was determined by
cutting one of the plurality of test bodies in a direction vertical
to a surface direction, and observing the resulting cross section
to carry out a measurement.
[0175] According to the repairing method of the present embodiment,
the acrylic resin composition infiltrates even into a portion at
which the plate 11 and the ceiling base material 12 are not
completely adhered to each other and a slight gap of more than 0 mm
was formed, and is cured thereat; and the thus formed cured body of
the acrylic resin composition serves to provide reinforcement.
[0176] When injecting the acrylic resin composition, it is possible
to inject an intended amount of resin, by injecting the composition
multiple times in stages, aiming to inject the acrylic resin
composition in an amount larger than an injection volume of the
resin composition, which is determined based on a maximum estimated
gap thickness and the area of the region to be injected.
[0177] Subsequently, each test body was left to stand for one day
at room temperature, to allow the acrylic resin composition
infiltrated into the interior of the injection hole 14 and between
the plate 11 and the ceiling base material 12 to be cured, to form
the cured body 15 of the acrylic resin composition. In this manner,
the repair of the plaster ceiling 10 was carried out.
[0178] [Evaluation of Repaired Plaster Ceiling]
[0179] For evaluation, the adhesion strength between the plate 11
and the ceiling base material 12 was measured, in each of the test
bodies of the plaster ceiling. The measurement of the adhesion
strength between the plate 11 and the ceiling base material 12 was
also carried out in a plaster ceiling, as a Comparative Example, in
which the cured body 15 of the acrylic resin composition had not
been formed in accordance with the repairing method of the present
embodiment.
[0180] The adhesion strength was measured using a tensile tester
(TECHNOTESTER, manufactured by Good Co., Ltd.) authorized by Japan
Society for Finishings Technology.
[0181] As a result, it has been found out that, in each of the test
bodies of the plaster ceiling in which the gap and the peripheral
portion thereof were sufficiently filled with the acrylic resin
composition and the resin cured body was partially formed, the
ceiling was reinforced due to the formation of the cured body 15 of
the acrylic resin composition at the gap portion. Such
reinforcement was observed even at a portion where the gap
thickness was as large as about 2 mm, and the adhesion strength
between the plate 11 and the ceiling base material 12 was reduced
to an extremely low level. The results have revealed that a peeling
strength in each of the test bodies repaired by the repairing
method according to the present disclosure is improved about from
67 times to 183 times, as compared to the peeling strength in the
ceiling of the Comparative Example, for which the present method
has not been used. This indicates that the adhesion strength
between the plate 11 and the ceiling base material 12 at the
repaired site in the plaster ceiling can be markedly improved by
carrying out the repairing method according to the present
disclosure.
[0182] Further, since the repairing method of Example 1 enables to
perform a repair from the side which does not affect the
appearance, for example, from a back side of the ceiling, it has
been confirmed that there is no difference in the appearance
between the ceiling before and after the repair, namely, that the
use of the present method does not affect the appearance of the
plaster ceiling.
[0183] As described above, the repairing method according to the
present disclosure allows for performing a repair or reinforcement
without affecting the appearance, unless a subject to be repaired
is a ceiling having cracks or the like extending to an outermost
layer thereof.
[0184] Further, even in the case of a plaster ceiling which
includes a wire mesh provided so as to extend across the plates, as
previously described, the present method allows for repairing the
ceiling without affecting the appearance, in the same manner. This
is because, since the plaster which has infiltrated through the
wire mesh to the back side of the ceiling forms a rough surface,
and the repair utilizing the cured body of acrylic resin can be
performed on the rough surface.
(2) Example 2
[0185] The same procedure as in the above described Example 1 was
repeated, except that an equal mixture of white fibers and bleached
fibers for plastering was used instead of the lye-treated straw
fibers, in the preparation of the plaster material for forming the
ceiling finishing material, to prepare each of a plurality of
plaster ceiling material test bodies.
[0186] Since white fibers and bleached fibers for plastering were
used in the plaster material for forming the finishing material,
the resulting plaster ceiling material test bodies of Example 2 had
a better appearance as compared to the plaster ceiling material
test bodies used in Example 1.
[0187] The white fibers for plastering are those obtained by
cutting sisal hemp fibers, and the bleached fibers for plastering
are those obtained using plant fibers such as jute and kenaf as raw
materials. The bleached fibers are usually prepared using waste
materials of jute bags for grains and the like, and by bleaching
and cutting fibers constituting the jute bags.
[0188] The resulting plaster ceiling material test bodies were each
repaired in the same manner as in Example 1.
[0189] [Evaluation of Repaired Plaster Ceiling]
[0190] In Example 2, as well, it has been found out that the
peeling strength in each of the test bodies repaired by the
repairing method according to the present disclosure is improved
about from 67 times to 183 times, as compared to the peeling
strength in the ceiling of the Comparative Example for which the
present method has not been used, in the same manner as in Example
1. The results have revealed that the adhesion strength between the
plate and the ceiling base material at the repaired site in the
plaster ceiling can be markedly improved by carrying out the
repairing method according to the present disclosure.
[0191] Further, it has been confirmed that there is no difference
in the appearance between the ceiling before and after the repair,
namely, that the use of the repairing method of Example 2 also does
not affect the appearance of the plaster ceiling.
[0192] The disclosure of Japanese Patent Application No.
2016-150662 filed on Jul. 29, 2016 is incorporated herein by
reference in their entirety. All publications, patent applications,
and technical standards mentioned in the present specification are
incorporated herein by reference to the same extent as if such
individual publication, patent application, or technical standard
was specifically and individually indicated to be incorporated by
reference.
* * * * *