U.S. patent application number 12/221957 was filed with the patent office on 2010-02-11 for roofing plate, installation and method therefor.
Invention is credited to Joshua S. Kelly.
Application Number | 20100031595 12/221957 |
Document ID | / |
Family ID | 41651638 |
Filed Date | 2010-02-11 |
United States Patent
Application |
20100031595 |
Kind Code |
A1 |
Kelly; Joshua S. |
February 11, 2010 |
Roofing plate, installation and method therefor
Abstract
A plate employed for securing substrate to a roofing structure
employs a recessed central hub through which a fastener is driven.
A barrier membrane covers the plate and is bonded in position to
the plate. A sidewall of the recessed hub includes at least one
vent opening to equalize pressure within the recessed hub during
installation and post-installation.
Inventors: |
Kelly; Joshua S.;
(Longmeadow, MA) |
Correspondence
Address: |
ALIX YALE & RISTAS LLP
750 MAIN STREET, SUITE 1400
HARTFORD
CT
06103
US
|
Family ID: |
41651638 |
Appl. No.: |
12/221957 |
Filed: |
August 8, 2008 |
Current U.S.
Class: |
52/408 ; 52/512;
52/746.11 |
Current CPC
Class: |
E04D 5/143 20130101;
E04D 5/148 20130101; E04D 5/145 20130101; E04D 5/147 20130101 |
Class at
Publication: |
52/408 ; 52/512;
52/746.11 |
International
Class: |
E04D 5/14 20060101
E04D005/14; E04D 5/00 20060101 E04D005/00; E04B 7/00 20060101
E04B007/00 |
Claims
1. A roofing plate comprising: a central recessed portion defining
a central axial opening; a raised portion surrounding said recessed
portion; a wall connecting said raised portion and central portion
and defining a vent opening; and a peripheral rim surrounding said
raised portion.
2. The roofing plate of claim 1 wherein said recessed portion, said
wall, said raised portion and said rim are generally symmetric
about said axial opening.
3. The roofing plate of claim 1 wherein said plate is metal.
4. The roofing plate of claim 3 further comprising a heat activated
adhesive applied to said raised portion.
5. The roofing plate of claim 1 wherein said plate is a one piece
integral member.
6. A method for installing a roofing system comprising: (a) driving
a fastener through a recessed portion of a roofing plate to secure
a substrate to a decking structure; (b) placing a membrane over
said plate and substrate; (c) bonding said membrane to said
substrate to form a cavity between said recessed portion and said
membrane; and (d) venting said cavity through a wall of said
plate.
7. The method of claim 6 wherein step 1 (c) further comprises
applying an adhesive to said plate.
8. The method of claim 6 wherein step (c) further comprises heating
a heat activated adhesive applied to the plate.
9. The method of claim 6 wherein step (a) further comprises driving
a fastener through a recessed portion of a roofing plate for a
multiplicity of roofing plates, and steps (c) and (d) further
comprise forming a cavity for each said plate and venting each said
cavity.
10. A roof installation comprising: a decking structure; a
substrate covering said decking structure; a roofing plate having a
recessed hub with a fastener driven through said hub and into said
structure to secure said substrate to said structure; a membrane
overlying said substrate and bonded to said substrate by adhesive
and forming a cavity between said recessed hub and said membrane;
and a vent path communicating through said plate with said
cavity.
11. The roof installation of claim 10 wherein said adhesive is heat
activated adhesive applied to said plate.
12. The roof installation of claim 10 wherein said plate is
metal.
13. The roof installation of claim 10 further comprising a
multiplicity of roofing plates and fasteners each of which form a
cavity and a vent path communicating through said plate with said
cavity.
14. The roof installation of claim 10 wherein said vent path is
located in a sidewall of said recessed hub.
Description
BACKGROUND
[0001] This application relates generally to roofing plates which
secure a substrate to a decking structure by means of a fastener.
More particularly, this application relates to roofing plates which
bond by means of an adhesive to an overlying barrier membrane.
[0002] In roofing installations to which the present application
relates a substrate is secured by a multiplicity of disc-like
plates to a decking structure. The substrate is typically a thermal
insulation layer such as a board of gypsum, resin foam or other
insulating materials. The decking structure is typically a
substructure of sheet steel, concrete or wood. Fasteners are driven
through a central recessed hub of the plate to secure the
substrate.
[0003] For some applications, the plate has a heat activated
adhesive on an upper surface of the plate. A barrier membrane,
which is typically a single ply waterproof membrane, is installed
over the substrate and the grid of metal plates. An induction tool,
which generates magnetic eddy currents in the metal plate, heats
the metal plate and activates the adhesive. Upon cooling and
setting, the adhesive then bonds the underside of the membrane to
the plate.
[0004] The membrane covers the plates prior to setting of the
adhesive. For some conventional applications, there is a tendency
for air to be trapped in the hub recess of the plate. The hub
portion is sealed to the substrate at the bottom by the fastener
head and at the top by the membrane. During the heating cycle, the
trapped air expands. When the plate cools and the adhesive sets, a
vacuum forms in the hub recess. The vacuum may draw the membrane
into the recess and form concave pockets or indentations across the
top of the membrane surface. The consequence of the membrane
indentations formed across the membrane surface is that the
stretching of the membrane into the indentations results in stress
on the membrane, and the membrane may also tend to be susceptible
to moisture retention--ultimately jeopardizing the barrier bonding
and integrity of the membrane.
[0005] Related phenomena may also occur in other systems that
employ various forms of plates and fastening techniques. When a
solvent based adhesive is applied to the top of the plates, the
solvent vaporizes and may partially become trapped in the hub
recess upon covering by the membrane. The trapped solvent may cause
the membrane to essentially form a convex-like bubble. Such bubbles
tend to cause peeling at the plate/membrane bonding interface and
jeopardize the bond.
SUMMARY
[0006] A roofing plate comprises a central recessed portion which
has a central axial opening. A raised portion surrounds the
recessed portion. A wall which may be of a frustoconical form
connects the raised portion and the central portion. A vent opening
is formed in the wall. A peripheral rim surrounds the raised
portion. In one embodiment the recessed portion wall, raised
portion and rim are generally symmetric about the axial opening.
The plate is preferably metal. A heat activated adhesive may be
applied to the raised portion of the plate. The plate may be a
one-piece integral member.
[0007] A method for installing a roofing system comprises driving a
fastener through a recessed portion of a roofing plate to secure a
substrate such as an insulation board to a decking structure. A
membrane is placed over the plate and substrate. The membrane is
bonded to the substrate to form a cavity between the recessed
portion and the membrane. The cavity is vented through a wall of
the plate. A heat activated adhesive may be applied to the plate
prior to securing the plate into position. Alternatively, an
adhesive may be applied to the plate after the plate is secured. A
multiplicity of roofing plates are employed for securing the
substrate to the deck. The cavities formed in the plates are vented
during the installation.
[0008] A roof installation comprises a decking structure. A
substrate covers the decking structure. A roofing plate has a
fastener driven through the hub and into the structure to secure
the substrate to the structure. A member overlies the substrate and
is bonded to the substrate by adhesive. A cavity is formed between
the hub and the membrane. A vent path through the plate
communicates with the cavity. The plate may be metal and the
adhesive may be heat activated adhesive, pre-applied to the plate.
The vent path is located in a side wall of the recessed hub.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a top plan view of a roofing plate;
[0010] FIG. 2 is a sectional view of the roofing plate of FIG. 1
taken along the line 2-2 thereof;
[0011] FIG. 3 is a sectional view of a roof installation, showing a
roofing plate, a fastener, a substrate, a decking structure and an
overlying barrier membrane;
[0012] FIG. 4 is a perspective view of an installment stage of a
roofing installation showing a plurality of roofing plates secured
to a substrate prior to covering by a roofing membrane; and
[0013] FIG. 5 is a sectional view of a prior art roof installation
showing a prior art roofing plate, a fastener, a substrate, a
decking structure and an overlying barrier membrane.
DETAILED DESCRIPTION
[0014] With reference to the drawings wherein like numerals
represent like parts throughout the several figures, a roofing
plate is designated generally by the numeral 10. The roofing plate
10 preferably has a generally disc-like shape and a sturdy,
reinforced construction. The plate is secured to the decking
structure 20 by a fastener 12 for retaining the substrate 22 in
position to a deck substructure. For a given installation, numerous
plates are employed for the substrate and positioned in a grid-like
pattern. The substrate 22 is typically a thermal insulation layer
such as an insulation board. The deck structure 20 may be a steel
sheet or concrete. The roofing plate is configured to properly
engage the substrate and facilitate proper orientation of the
fastener.
[0015] The roofing plate 10 has a central recessed hub 30 which
defines the central opening 32 for the fastener. The bottom surface
34 of the hub provides the plate engagement structure for the
underside of the head 14 of the fastener. The peripheral side 36 of
the central hub tapers upwardly (preferably a frustoconical
surface) to integrally join with an annular raised platform portion
40. The peripheral portion of the raised platform integrally tapers
downwardly to form a circumferential rim 42 which engages the
substrate. Surface 34 and rim 42 are generally parallel and have a
spacing slightly offset from a co-planar relationship. In some
embodiments, the rim 42 is co-planar with the central surface 34 of
the recessed hub. In the illustrated embodiment, the plate 10, rim
42, raised platform 40 and central hub 30 are generally axially
symmetric about a central axis through the fastener opening. The
plate may be stamped from metal. Other plate shapes which employ a
recessed hub are also possible.
[0016] A vent opening 50 is formed in the tapered recessed wall 36
of the hub. In one embodiment, for a plate having a platform
diameter P of 80 mm or 2.66 ins. and a hub surface diameters of
1.16 ins., the diameter of the vent opening 50 is 0.125 ins. and
the opening is located at the midpoint of the frustoconical side
36. The diameter H of the hub is 1.51 ins. and has a depth D of
approximately 0.17 ins. In some embodiments more than one such
opening may be formed. The opening 50 provides a vent passage which
tends to equalize the pressure within the hub and surrounding
region during installation and post-installation and throughout the
useful life of the installation provided by the roofing plates.
[0017] Roofing plate 10 may be affixed with a heat activated
adhesive 44 which is applied to the raised platform 40 of the
plate. In typical roof installations, numerous roofing plates are
secured to the substrate via a fastener which tightens against the
recessed portion.
[0018] With reference to FIGS. 3 and 4, a barrier membrane 24 is
then installed over the top of the roofing plates 10 and the
substrate 20. The barrier membrane is typically a single-ply
moisture resistant or waterproof sheet. The sheet is transported to
the roofing structure in roll form and unrolled across the
substrate.
[0019] An induction tool (not illustrated) on top of the membrane
24 is brought into the vicinity of the metal plates positioned
under the membrane. The induction tool is energized so that
magnetically induced eddy currents within the metal plate 10 heat
the metal plate to thereby activate the adhesive 44. The adhesive,
which is sandwiched between the membrane 24 and the platform 40 of
the plate, is ultimately cooled so that the adhesive sets and bonds
the barrier membrane to the plates. In some embodiments, the
adhesive may be mixed with metallic particles and the plate may not
be metal.
[0020] Because in conventional installations, the barrier membrane
essentially hermetically seals across the top of the hub and the
bottom surface of the hub is sealingly engaged against the
substrate, an air pocket may be typically formed in the hub. Under
such conditions, when the prior art plate 11 cools, a seal forms
between the underside of the fastener head and the top side of the
plate adjacent the hole. A vacuum could be created in the hub
thereby forming a depression 27 such as illustrated in FIG. 5.
[0021] However, with reference to FIG. 3 and plate 10, because of
the vent opening 50, the pressure will rapidly be equalized with
the surrounding region and consequently upon cooling and bonding of
the plate, the pressure within the hub recess will not be
sufficiently different to result in creation of an indentation in
the membrane. The membrane will essentially bond in a substantially
planar, flat relationship 26 across the entire expanse of the plate
(which may-be slightly elevated above the substrate).
[0022] In an installation wherein the induction heat activated
process is not employed, the roofing plates are secured against the
substrate in a grid-like pattern to anchor the substrate to the
decking structure. Solvent based adhesive is then sprayed or
otherwise applied across the tops of plates. The barrier membrane
is then laid or rolled over the substrate and plates. Any solvent
which typically vaporizes off from the adhesive which may become
trapped in the recessed hub will be vented via the vent opening 50
to essentially equalize the local pressure and prevent any bubbling
effect across the membrane.
[0023] While preferred embodiments of the foregoing have been set
forth for purposes of description, the foregoing should not be
deemed a limitation. Accordingly, various modifications,
adaptations or alternatives may occur to one skilled in the art
without departing from the spirit and the scope of the appended
claims.
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