U.S. patent application number 11/318160 was filed with the patent office on 2006-06-29 for waterproof sheet structure for a cool roof.
Invention is credited to Choong Yup Kim.
Application Number | 20060137272 11/318160 |
Document ID | / |
Family ID | 36609762 |
Filed Date | 2006-06-29 |
United States Patent
Application |
20060137272 |
Kind Code |
A1 |
Kim; Choong Yup |
June 29, 2006 |
Waterproof sheet structure for a cool roof
Abstract
A waterproof sheet structure for a cool roof includes a
waterproof sheet layer and a top reinforce layer placed on one side
of the waterproof layer. The top reinforce layer is impregnated in
a liquid polymer and then dried, and is treated to have a light
color. The liquid polymer has fire retardant property. The top
reinforce layer is made of a fiberglass cloth, which includes a
plurality of glass fibers woven with one another. The polymer fill
gaps between the woven fibers. The polymer is impregnated onto the
fiberglass cloth in such a thickness so that there are no glass
fibers exposed out of the polymer. The waterproof sheet is made by
forming the fiberglass cloth, and then coating asphalt on the
fiberglass cloth with a constant thickness.
Inventors: |
Kim; Choong Yup; (Rancho
Palos Verdes, CA) |
Correspondence
Address: |
PARK LAW FIRM
3255 WILSHIRE BLVD
SUITE 1110
LOS ANGELES
CA
90010
US
|
Family ID: |
36609762 |
Appl. No.: |
11/318160 |
Filed: |
December 23, 2005 |
Current U.S.
Class: |
52/411 |
Current CPC
Class: |
E04D 5/142 20130101;
E04D 5/10 20130101; E04D 5/148 20130101 |
Class at
Publication: |
052/411 |
International
Class: |
E04B 5/00 20060101
E04B005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 29, 2004 |
KR |
10-2004-0114610 |
Claims
1. A waterproof sheet structure for a cool roof comprising: a) a
waterproof sheet layer; and b) a top reinforce layer placed on one
side of the waterproof layer; wherein the top reinforce layer is
impregnated in a liquid polymer and then dried, and is treated to
have a light color.
2. The waterproof sheet structure according to claim 1, wherein the
waterproof sheet layer comprises an asphalt sheet.
3. The waterproof sheet structure according to claim 1, wherein the
asphalt sheet has a thickness in a range from about one (1) to
about five (5) mm.
4. The waterproof sheet structure according to claim 3, wherein the
asphalt sheet has a thickness in a range from about one half (1.5)
to about three (3) mm.
6. The waterproof sheet structure according to claim 1, wherein the
liquid polymer has fire retardant property.
7. The waterproof sheet structure according to claim 1, wherein the
top reinforce layer comprises a fiberglass cloth.
8. The joint sealing structure according to claim 7, wherein the
fiberglass cloth comprises a plurality of glass fibers woven with
one another, and wherein the polymer fill gaps between the woven
fibers.
9. The joint sealing structure according to claim 8, wherein the
polymer is impregnated onto the fiberglass cloth in such a
thickness so that there are no glass fibers exposed out of the
polymer.
10. The joint sealing structure according to claim 7, wherein each
of the waterproof sheets is made by forming the fiberglass cloth,
and then coating asphalt on the fiberglass cloth with a constant
thickness.
11. The waterproof sheet structure according to claim 7, wherein
the fiber glass cloth is soaked in the liquid polymer, and then
dried at a temperature in a range from about 100 to about 150
degree Celsius.
12. The waterproof sheet structure according to claim 11, wherein
the fiber glass cloth is dried for a time period in a range from
about 3 to about 5 minutes.
13. The waterproof sheet structure according to claim 7, wherein
the fiberglass cloth has a thickness in a range from about 0.1 to
about 0.3 mm.
14. The waterproof sheet structure according to claim 1, further
comprising a base layer placed on the other side of the waterproof
layer.
15. The waterproof sheet structure according to claim 14, wherein
the top reinforce layer is laminated on one side of the waterproof
sheet layer, and wherein the base layer is laminated on the other
side of the waterproof layer.
16. The waterproof sheet structure according to claim 14, wherein
the base layer comprises a fiber non-woven fabric.
17. The waterproof sheet structure according to claim 14, wherein
the base layer comprises a fine sand layer.
18. The waterproof sheet structure according to claim 14, wherein
the base layer comprises a polyester film.
19. The waterproof sheet structure according to claim 1, wherein
the liquid polymer is selected from the group consisting of acrylic
resin, epoxy resin, polyurea resin, and polyurethane.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The application claims priority on Korean Patent Application
No. 10-2004-0114610, filed on Dec. 29, 2004, and the disclosure of
which is incorporated by reference into this application as if
fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is related to a waterproof sheet
structure for a cool roof. More particularly, the invention is
related to a waterproof sheet that has fire retardancy and light
reflectivity while using common and cheap materials.
[0004] 2. Background of the Related Art
[0005] In general, a waterproof material is applied to the rooftop
of the building or the top floor of the parking lot, in order to
prevent a water leakage due to rainfall, or the like. Commonly,
water-soluble or oil-soluble paint film waterproof material,
asphalt waterproof material, and asphalt sheet waterproof material
are employed.
[0006] In case of the paint film waterproof material, a liquid
waterproof agent is repeatedly coated on the surface of a
structure, to thereby form a film of paint. A tight waterproof
layer can be formed, and a narrow and difficult area can be
waterproofed with a simple process. However, a uniform thickness of
waterproof layer cannot be achieved, and the peel-off of the
waterproof layer is prone to occur by vapor pressure due to water
contained in the concrete bottom floor. If a crack is generated in
the structure, then the paint film also is cracked, thereby leading
to a water leakage.
[0007] In case of the asphalt waterproofing material, a waterproof
layer is formed using asphalt as its main material. In this
process, asphalt is heated to melt and the melted asphalt is coated
repeatedly in the area to be waterproofed to thereby form a
waterproof layer. Alternatively, asphalt is rubberized and formed
in the form of a sheet, and in installation process, the asphalt
sheets are arranged with their edges being overlapped. Then, the
overlapped connecting portions are heated and adhered with a torch
or the like.
[0008] Among the above asphalt waterproofing processes, the asphalt
sheet process has been widely used because its installation is
simple, a uniform thickness of waterproof layer can be obtained,
and the construction period can be shortened.
[0009] However, in case where the asphalt sheet process is carried
out in an exposed waterproofing mode, as the waterproof sheet is
exposed to the sunlight for a longer period of time, the surface
thereof is deteriorated and thus the service life is
disadvantageously shortened. That is, the ultraviolet rays
contained in the sunlight accelerates the polymerization of
hydrocarbon molecules in the waterproof asphalt sheet and thus
carbonizes the surface thereof, thereby causing a crack in the
asphalt and thus a water leakage therethrough. In addition, the
asphalt material is susceptible to heat, and thus when a fire is
caught, it is easily melted down and generates poisonous gases.
[0010] In order to solve these problems, commonly a protective
mortar layer or a crushed aggregate layer has been formed on top of
the asphalt sheet. In particular, U.S. Pat. No. 5,096,759 discloses
a protection structure of an asphalt sheet, in which an aluminum
foil is laminated on the asphalt sheet to protect the lower asphalt
layer. The aluminum foil, which is attached to the top of the
waterproof asphalt sheet, reflects the sunlight and blocks harmful
ultraviolet rays from asphalt, thereby lengthening the service life
of the waterproof asphalt sheet. In addition, since aluminum is
very resistant to heat, with the aluminum foil attached, the
fire-retardancy of the entire waterproof structure including the
waterproof asphalt sheet is significantly improved.
[0011] However, in case of the conventional waterproof asphalt
sheet having an aluminum surface, the aluminum foil laminated on
top thereof reacts with oxygen in the air and thus is easily
oxidized. If the aluminum foil is oxidized, rust is created in the
surface thereof so that its fire-retardancy is deteriorated and at
the same time its surface gloss is lost thereby lowering the
reflectivity to the sunlight. Consequently, the function as a cool
roof system is lost.
[0012] The cool roof system is one of various approaches for
minimizing the electric energy consumed for cooling purpose. In
other words, light colored materials having a higher reflectivity
to the sunlight are applied to the rooftop of buildings, instead of
traditional dark colored ones. Therefore, the solar heat is
prevented from being transferred into the inside of the building,
thereby minimizing heating-up of the interior of the building. As a
method of realizing the cool roof system, a white colored polymer
layer is formed on the roof surface, or a roof shingle is
installed. Generally, the former method has been widely used.
[0013] As described above, in case of the aluminum foil, the
sunlight is reflected to some extent to thereby serve as a cool
roof system. However, as time passes, its surface is oxidized to
reduce the reflectivity to the sunlight, and the aluminum foil is
contacted with alkaline component of the bottom concrete and easily
corroded. Therefore, an adequate reflectivity to be acceptable as a
cool roof system cannot be maintained. There is a need to provide
an improved solution.
[0014] The process for placing the conventional waterproof asphalt
sheet including the aluminum-laminated asphalt sheet is hereafter
explained. First, a primer is coated, and then the waterproof
asphalt sheet is installed. The waterproof asphalt sheets are
placed in a way that they are arranged in such a way that the edges
of neighboring sheets are overlapped. Thereafter, the overlapped
connecting portions (edges) are heat-melted and adhered using a
torch or the like, to thereby provide waterproofing
[0015] However, in this method, since the connecting portions are
heated up and melted in order to adhere them together, excessive
heat may result in damage and deformation of the sheet. In
contrast, if an adequate amount of heat is not applied, the
connecting portions cannot be adhered uniformly, which may lead to
a water leakage.
[0016] In order to solve the above problems, Korean Laid-open
Patent No. 2001-95666 discloses a joint sealing structure (also
known as an I-joint structure) for the waterproof asphalt sheets.
This joint structure is composed of asphalt sheets installed with a
certain gap in between, a melted asphalt filled in the gap, a
reinforced fiber cloth installed above the melted asphalt, and
another melted asphalt coated on the reinforced fiber cloth. In
case where this joint sealing structure can be used, the connecting
portions of the sheet can be uniformed covered by the melted
asphalt, thereby enabling a perfect waterproofing treatment.
[0017] However, the above-described I-joint structure fails to
guarantee fire-retardancy for the connecting portions between the
sheets, even in the case of the aluminum-surfaced asphalt sheet as
described previously. It is because the connecting portions between
the sheets are composed of only asphalt, although the asphalt sheet
itself has a fire-retardancy by means of the aluminum foil attached
to the surface of the asphalt sheet. As described above, if the
connecting portions between the sheets do not exhibit a proper
fire-retardancy, the fire-retardancy for the whole waterproofing
system would not be acceptable.
[0018] Therefore, even in case where a fire-retardancy is provided
as in the aluminum-surfaced asphalt waterproof sheet, in order to
apply the I-joint sealing structure to the connection portions
between the sheets, an appropriate improvement is required so as to
provide an adequate fire-retardancy to the connecting portions.
SUMMARY OF THE INVENTION
[0019] Therefore, the present invention has been made in view of
the above problems, and it is an object of the present invention to
provide a waterproof asphalt sheet suitable for a cool roof system,
in which the problems with the aluminum waterproof sheet is
eliminated, its fire-retardancy is maintained semi-permanently, and
at the same time a high reflectivity to the sunlight is
achieved.
[0020] Another object of the invention is to provide a waterproof
asphalt sheet, which does not require any separate cool roof
coating work.
[0021] A further object of the invention is to provide a joint
sealing structure for the waterproof asphalt sheet for a cool roof,
in which, in the case where the conventional I joint process is
applied to the waterproof asphalt sheet for a cool roof according
to the invention, its fire-retardancy can be maintained over the
entire waterproofing area including the connecting portion between
the sheets.
[0022] To accomplish the above objects, according to an aspect of
the present invention, there is provided a waterproof sheet
structure suitable for a cool roof system and having
fire-retardancy.
[0023] The waterproof sheet structure includes a waterproof sheet
layer, and a top reinforce layer placed on one side of the
waterproof layer. The top reinforce layer is impregnated in a
liquid polymer and then dried, and is treated to have a light color
so that the waterproof layer that lies under the top reinforce
layer is prevented from being heated.
[0024] The waterproof sheet layer may be made of an asphalt
sheet.
[0025] Preferably, the asphalt sheet has a thickness in a range
from about one (1) to about five (5) mm. More preferably, the
asphalt sheet has a thickness in a range from about one half (1.5)
to about three (3) mm.
[0026] The liquid polymer has fire retardant property so that the
top reinforce layer, and thus the entire sheet structure has fire
retardant property that is required for a roof.
[0027] The top reinforce layer may be made of a fiber glass
cloth.
[0028] The fiberglass cloth includes a plurality of glass fibers
woven with one another, and wherein the polymer fill gaps between
the woven fibers.
[0029] The polymer is impregnated onto the fiberglass cloth in such
a thickness so that there are no glass fibers exposed out of the
polymer.
[0030] Each of the waterproof sheets is made by forming the
fiberglass cloth, and then coating asphalt on the fiberglass cloth
with a constant thickness.
[0031] The fiber glass cloth is soaked in the liquid polymer, and
then dried at a temperature in a range from about 100 to about 150
degree Celsius for a time period in a range from about 3 to about 5
minutes.
[0032] Preferably, the fiberglass cloth has a thickness in a range
from about 0.1 to about 0.3 mm.
[0033] The waterproof sheet structure may further include a base
layer placed on the other side of the waterproof layer.
[0034] The top reinforce layer and the base layer are laminated on
the sides of the waterproof layer.
[0035] The base layer may be a fiber non-woven fabric, a fine sand
layer, or a polyester film.
[0036] The liquid polymer is selected from the group consisting of
acrylic resin, epoxy resin, polyurea resin, and polyurethane.
[0037] The fiber non-woven fabric functions to enhance the tensile
strength of the asphalt sheet.
[0038] The fiberglass cloth functions to prevent the lower asphalt
sheet from the ultraviolet rays of the sunlight, and is laminated
above the asphalt sheet to provide a fire-retardancy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The above and other objects, features and advantages of the
present invention will be apparent from the following detailed
description of the preferred embodiments of the invention in
conjunction with the accompanying drawings, in which:
[0040] FIGS. 1(a) and 1(b) are a perspective view and a
cross-section showing a waterproof sheet structure for a cool roof
according to one embodiment of the invention;
[0041] FIGS. 2(a) and 2(b) are a perspective view and a
cross-section showing a waterproof sheet structure for a cool roof
according to another embodiment of the invention;
[0042] FIGS. 3(a) and 3(b) are a perspective view and a
cross-section showing a waterproof sheet structure for a cool roof
according to further embodiment of the invention;
[0043] FIG. 4 illustrates a joint sealing structure of waterproof
sheets according to the invention;
[0044] FIG. 5 illustrates a practical construction of the joint
sealing structure of the invention;
[0045] FIG. 6 schematically shows glass fibers of which a
fiberglass cloth is consisting;
[0046] FIG. 7 is a schematic cross section that illustrates the
glass fibers are completely impregnated in polymer;
[0047] FIG. 8 a schematic cross sectional view illustrating an
asphalt layer is formed on the fiberglass cloth that is impregnated
with the polymer; and
[0048] FIG. 9 is a cross sectional view showing a fiberglass tape
covered directly over the joining region of two waterproof
sheets.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0049] Reference will now made in detail to the preferred
embodiment of the present invention with reference to the attached
drawings.
[0050] FIGS. 1(a) and 1(b) illustrate a waterproof sheet structure
4 of a cool roof according to one embodiment of the invention. The
waterproof asphalt sheet 4 of the invention comprises a fiber
non-woven fabric 10, an asphalt sheet 20, and a glass fiber fabric
30 which will be hereafter explained in sequence from the lowest
layer.
[0051] The fiber non-woven fabric 10 constitutes the lowest layer
of the waterproof sheet structure. The fiber non-woven fabric 10
serves as reinforcement for strengthening the waterproof sheet
structure of the invention. The specific material for the fiber
non-woven fabric 10 is not particularly limited, and a non-woven
fabric made of a synthetic fiber such as polyester can be employed
in common.
[0052] The fiber non-woven fabric 10 is composed of numerous fibers
and serves as enhancing the tensile strength of the waterproof
asphalt sheet for a cool roof. At the same time, in case where the
waterproof asphalt sheet for a cool roof according to the invention
employs an I-joint for connecting plural sheets, a liquid polymer
to be filled from above permeates between the fiber non-woven
fabrics and adhered thereto. Therefore, the bonding between the
waterproof sheet and the polymer liquid is more strengthened to
thereby further improve the effect of waterproofing. The fiber
non-woven fabric 10 is laminated or adhered with the asphalt sheet
20 by heat-melting or by an adhesive material.
[0053] The asphalt sheet 20 is formed above the fiber non-woven
fabric 10. According to the invention, the thickness of the asphalt
sheet 20 varies with applications. In practice, a thickness of 1-5
mm is applied. However, preferably a thickness of 1.5.about.3 mm is
suitable.
[0054] Above the asphalt sheet 20 is formed a fiberglass cloth 30.
According to the invention, the fiberglass cloth 30 is woven
transversally and longitudinally of fiberglass. The fiberglass
cloth 30 holds a thickness of 0.1-0.3 mm such that the waterproof
sheet structure has an adequate fire-resistant property. The
fiberglass cloth 30 is laminated or adhered with the asphalt sheet
20 by heat-melting or by an adhesive material.
[0055] The fiberglass cloth 30 is formed by a method in which
transversely and longitudinally woven fiberglass is embedded into a
liquid polymer 31 and then dried. The fiberglass cloth 30 is
treated to have a light color such that it reflects the sunlight to
prevent the lower layer from heating up.
[0056] In other words, the fiberglass cloth 30 is fabricated in
such a manner that fiberglass is soaked in the liquid polymer 31,
and the fiberglass soaked with the liquid polymer 31 is dried in a
drying chamber at 100-150.degree. C. for 3-5 minutes through hot
air, thereby curing the polymer 31.
[0057] As the polymer 31, acrylic resin, epoxy resin, polyurea, and
polyurethane are preferred. Particularly, acrylic resin is most
preferred. In addition, it is preferable that the polymer 31 is
fire-retard-treated and thus has a fire resistance in itself.
[0058] The fiberglass cloth 30 constitutes the uppermost layer of
the waterproof asphalt sheet of the invention. The fiberglass cloth
30 reflects the sunlight such that the lower layers of the
waterproof asphalt sheet and the roof structure are prevented from
being heated up due to the sunlight. Therefore, the fiberglass
cloth 30 has a color having a high reflectivity to the sunlight. In
particular the while color is preferable.
[0059] The fiberglass cloth 30 is cured with the polymer 31, and
then may be introduced into a construction site and installed,
independently from the asphalt sheet 20. It is however preferred to
be formed integrally with the fiber non-woven fabric 10 and the
asphalt sheet 20 in the factory. In this way, in case where the
fiberglass cloth 30, the asphalt sheet 20 and the fiber non-woven
fabric 10 are integrally formed in a factory and delivered to the
construction site, if the waterproof asphalt sheet for a cool roof
according to the invention is installed at the construction site, a
waterproof work, a fire-resistance work, and a cool roof coating
work are simultaneously carried out.
[0060] FIGS. 2(a) to 3(b) illustrate a waterproof asphalt sheet for
a cool roof according to another embodiment of the invention.
[0061] FIGS. 2(a) and 2(b) show another embodiment of the
invention, in which below the asphalt sheet 20 is formed a fine
sand layer 11 instead of the fiber non-woven fabric 10. In FIGS.
3(a) and 3(b), a polyester film 12 is formed, instead of the fiber
non-woven fabric 10.
[0062] FIG. 4 illustrates a joint sealing structure for the asphalt
sheets according to one embodiment of the invention. In FIG. 4, a
joint sealing structure between neighboring two waterproof asphalt
sheets is illustrated. A first asphalt sheet 100 and a second
waterproof asphalt sheet 200 for a cool roof are installed in such
a manner that their edges are spaced apart from each other with a
desired gap in-between. A liquid polymer is coated above the
connecting portion between the first and second waterproof asphalt
sheets 100, 200 and filled inside the gap in-between. A polymer
filled portion 40 is formed in such a way to be projected in a
convex form upwards the first and second waterproof asphalt sheet
100, 200. Each of the first and second waterproof asphalt sheet
100, 200 is composed of an asphalt sheet 20, a fiberglass cloth 30
laminated on top of the asphalt sheet 20, and a fiber non-woven
fabric 10 formed underneath the asphalt sheet 20. The fiberglass
cloth 30 is impregnated with a liquid polymer 31 and dried, and
treated to have a light color such that the lower layer thereof can
be prevented from being heated up by reflecting the sunlight. The
polymer 31 itself has a fire-retardant property.
[0063] On the other hand, a fine sand layer 11 may be formed as
shown in FIGS. 2(a) and 2(b), or a polyester film 12 may be formed
as depicted in FIGS. 3(a) and 3(b), instead of the fiberglass cloth
10.
[0064] The polymer used for the polymer filled portion 40 has a
waterproofing property and also a fire-retardant characteristic.
The polymer is selected from acrylic resin, epoxy resin,
polyurethane, polyurea, and asphalt. In particular, polyurethane,
or polyurea can be placed in a liquid state at room temperature,
and, similar to where asphalt is used, they do not require any
heating process so that they can be used very conveniently.
[0065] Similar to the polymer 31 impregnated and cured in the
fiberglass cloth 30, the polymer used in the polymer filled portion
40 employs one treated to have a light color. Therefore, the entire
waterproofing area including the connecting portion forms a cool
roof system, including the area where the waterproof asphalt sheet
of the invention is placed.
[0066] Referring back to FIG. 4, a fiberglass tape 50 is further
provided above the polymer filled portion 40, in such a way to
enclose the polymer filled portion along the gap between the first
and second waterproof asphalt sheets 100, 200. Similar to the
fiberglass cloth 30, the fiberglass tape 50 is impregnated with a
liquid polymer having a waterproofing and fire-retardant
properties, and then dried. Similarly, it is treated to have a
light color so as to reflect the sunlight and thus prevent the
heating-up of the lower layers.
[0067] In this way, in case where the fiberglass tape 50 is
installed additionally, the fire-retardant characteristic of the
waterproof asphalt sheet of the invention is further strengthened.
It is because the polymer filled portion 40 itself has a
fire-retardant property and also the fiberglass tape 50 installed
above the polymer filled portion 40 has a fire-retardant
characteristic.
[0068] In case where the fire-retardancy of the polymer filled
portion 40 is determined to be adequate, the fiberglass tape 50 may
be omitted.
[0069] Referring to FIG. 5, a method of forming the joint sealing
structure between the waterproof asphalt sheets is explained.
[0070] First, the waterproof asphalt sheets 100 and 200 for a cool
roof are spread-installed on the roof surface in such a manner that
the two neighboring waterproof asphalt sheets 100 and 200 have a
desired gap in-between. Preferably, the gap between the neighboring
waterproof asphalt sheets 100 and 200 is about 0.7.about.1.5 cm,
and more preferably, about 1.0 cm.
[0071] The connecting portion formed between the neighboring
waterproof asphalt sheets 100 and 200 is coated with a liquid
polymer such as polyurethane so as to fill the gap between the
sheets. In this step, the liquid polymer is coated adequately to
the extent that it can fill the entire gap between the waterproof
asphalt sheets 100 and 200 and further cover slightly the upper
portion thereof.
[0072] The fiberglass tape 50 is installed above the polymer filled
portion 40, which is filled with a liquid polymer as described
above. In this step, the width of the fiberglass tape 50 is chosen
to be wider than the gap between the waterproof asphalt sheets 100
and 200, such that the whole waterproofing area is covered with
fiberglass. In case where the gap between the waterproof asphalt
sheets 100 and 200 is 1 cm, the width of the tape is suitable to be
about 10-15 cm. For the convenience of installation, the fiberglass
tape 50 is preferred to be manufactured in the form of a
self-adhesive type.
[0073] In this way, the whole area to be waterproofed, which
includes the asphalt sheet 20 and the polymer filled portion 40, is
covered with the fiberglass cloth 30 and the fiberglass tape 50.
The fiberglass cloth 30 and the fiberglass tape 50 are impregnated
and dried in the liquid polymer 31, and treated to have a light
color so as to prevent heating-up of the lower layer by reflecting
the sunlight. Therefore, the whole waterproofing area serves as a
cool roof system.
[0074] As shown in FIGS. 6 and 7, the fiberglass cloth 30 includes
a plurality of glass fibers 52 woven with one another. When the
fiberglass cloth 30 is impregnated with the polymer 31, the polymer
31 fill gaps between the woven fibers 52. The polymer 31 is
impregnated onto the fiberglass cloth 30 in such a thickness so
that there are no glass fibers 52 exposed out of the polymer
31.
[0075] As shown in FIG. 8, the waterproof sheet is made by forming
the fiberglass cloth 30 as explained above referring FIGS. 6 and 7,
and then coating asphalt 54 on the fiberglass cloth 30 with a
constant thickness.
[0076] This process of forming an asphalt layer is commonly called
`asphalt knife coating.` As shown in FIG. 8, molten asphalt 54 is
poured over the fiberglass cloth 30. A knife 56 regulates the
thickness of the asphalt sheet 20 as the asphalt solidifies. Since
the fiberglass cloth 30 is made so that a fluid cannot penetrate
into it, molten asphalt can be poured directly onto the fiberglass
cloth 30 without the problem of leaking.
[0077] With the above construction, manufacture of the waterproof
asphalt sheet 4 is substantially simplified. This is because the
top reinforce layer, or the fiberglass cloth provides light color
and fire retardancy, which are required for external portion of a
waterproof structure, and provides a fluid tight layer that
facilitates asphalt coating.
[0078] The present invention also has a great advantage over the
prior art in the aspect of maintaining uniform appearance. In the
prior art, waterproof sheets were joined by overlapping edges of
adjacent waterproof sheets, and surface layer such as aluminum
layer was not provided on the overlapping portion of the waterproof
sheet. This increased complexity of manufacturing. Since the
waterproof sheet of the present invention does not require
overlapping to join the sheets, the entire sheet can be
manufactured as a single uniform sheet.
[0079] Referring back to FIG. 4, preferably, the width a of the gap
between the first and second waterproof sheets is in a range from
about 0.7 cm to about 1.5 cm, and the width b of the fiberglass
tape 50 is in a range from about 10 cm to 15 cm.
[0080] As shown in FIG. 9, the fiberglass tape 50 may be installed
over the area that the edges of the first waterproof sheet and the
second waterproof sheet are adjacently positioned without a
polymer-filled portion between the sheets.
[0081] The present invention provides the following advantageous
effects.
[0082] First, the invention eliminates the problems with the
aluminum waterproof sheet, maintains its fire-retardancy
semi-permanently, and at the same time has a high reflectivity to
the sunlight, thereby providing a waterproof asphalt sheet suitable
for a cool roof system.
[0083] That is, in the case of the conventional waterproof asphalt
sheet having an aluminum surface, the aluminum foil laminated on
top thereof reacts with oxygen in the air and thus is oxidized
easily, so that its fire-retardancy is deteriorated. Also, the
gloss of the aluminum foil surface is easily lost so that the
reflectivity to the sunlight is significantly lowered. Therefore,
it cannot function properly as a cool roof system. In the present
invention, however, on top of the asphalt sheet 20 is installed the
fiberglass cloth 30, which is treated to have a light color, such
that its fire-retardancy and reflectivity to the sunlight can be
maintained for a long time. Therefore, a waterproof asphalt sheet
suitable for a cool roof system can be achieved.
[0084] Second, the present invention provides a waterproof asphalt
sheet, which does not require any separate cool roof coating
work.
[0085] In other words, according to the present invention, the
asphalt sheet 20 is integrally formed with the fiberglass cloth 30,
which is treated to have a light color and formed above the asphalt
sheet 20. The waterproof asphalt sheet of the invention can be
simply cut and installed in the construction site to thereby
provide a cool roof system. As such, it does not require any
separate coating process for enhancing the reflectivity to the
sunlight.
[0086] Third, in the case where the I joint process is adopted to
the waterproof asphalt sheet for a cool roof according to the
invention, a joint sealing structure for the waterproof asphalt
sheet for a cool roof can be provided, in which its fire-retardancy
can be maintained over the entire waterproofing area including the
connecting portion between the sheets.
[0087] In other words, the connecting portion between the first and
second waterproof asphalt sheets 100 and 200 is coated with a
liquid polymer having a waterproofing and fire-retardant
characteristics, to thereby form the polymer filled portion 40.
Above the polymer filled portion 40 is additionally installed the
fiberglass tape 50 having a fire-retardancy. Therefore, a
fire-retardancy can be maintained over the entire waterproofing
area including the connecting portion.
[0088] While the present invention has been described with
reference to the particular illustrative embodiments, it is not to
be restricted by the embodiments but only by the appended claims.
It is to be appreciated that those skilled in the art can change or
modify the embodiments without departing from the scope and spirit
of the present invention.
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