U.S. patent application number 10/859277 was filed with the patent office on 2004-12-09 for cool roof covering.
Invention is credited to Harris, Christopher J., Macuga, James A..
Application Number | 20040244316 10/859277 |
Document ID | / |
Family ID | 33514037 |
Filed Date | 2004-12-09 |
United States Patent
Application |
20040244316 |
Kind Code |
A1 |
Macuga, James A. ; et
al. |
December 9, 2004 |
Cool roof covering
Abstract
A roof covering (10) comprising a plastic film (40) and an
adhesive (46) positioned under the lower film surface (44). The
film (40) can be a plastic film selected to provide substantial
solar reflectance and high thermal emittance and the adhesive (46)
can be a pressure-sensitive adhesive. The roof covering (10) of the
present invention can be provided in a roll, sheets, or other
medium, and it can be applied to an EPDM membrane after the
membrane is assembled to the roof. The roof covering (10) can
instead be incorporated into a laminate including an EPDM membrane
and assembled to the roof at the same time as the membrane.
Inventors: |
Macuga, James A.; (Concord,
OH) ; Harris, Christopher J.; (Los Angeles,
CA) |
Correspondence
Address: |
Cynthia S. Murphy
Renner, Otto, Boisselle & Sklar, LLP
1621 Euclid Avenue, Nineteenth Floor
Cleveland
OH
44115-2191
US
|
Family ID: |
33514037 |
Appl. No.: |
10/859277 |
Filed: |
June 2, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60496099 |
Aug 18, 2003 |
|
|
|
60474970 |
Jun 2, 2003 |
|
|
|
Current U.S.
Class: |
52/198 |
Current CPC
Class: |
E04D 5/10 20130101; B32B
25/08 20130101; C09J 7/22 20180101; B32B 2419/06 20130101; B32B
27/08 20130101; B32B 2333/12 20130101; B32B 7/12 20130101; B32B
27/10 20130101; B32B 2323/16 20130101; C08K 3/22 20130101; E04D
5/06 20130101; C09J 7/38 20180101; C09J 2301/204 20200801; C09D
7/61 20180101; B32B 27/20 20130101 |
Class at
Publication: |
052/198 |
International
Class: |
E04B 007/00 |
Claims
1. A roof covering comprising a film and an adhesive; the film
having a first surface and a second surface and the adhesive being
positioned on the second surface.
2. A roof covering as set forth in claim 1, wherein the film has a
thickness in the range of about 3 to about 50 mils.
3. A roof covering as set forth in claim 2, wherein the film has a
width of at least 2 feet.
4. A roof covering as set forth in claim 3, wherein the film has a
width of about 30 inches to about 80 inches.
5. A roof covering as set forth in claim 4, wherein the film
comprises a plastic film.
6. A roof covering as set forth in claim 5, wherein the plastic
film comprises acrylics such as poly(methyl methacrylate) and
poly(ethyl methacrylate), polystyrenes such as poly(p-styrene) and
syndiotactic polystyrene, and styrene-based copolymers, vinylic
such as polyvinyl chloride, polyvinylicene chloride, polyvinylidene
fluoride and polyvinylidone dichloride, polyolefin homopolymers
such as polyethylene and polypropylene, copolymers of ethylene,
propylene and/or butylene, copolymers containing ethylene such as
ethylene vinyl acetate, ethylene acrylic acid and ethylene
methacrylate copolymer, polyesters such as polyethylene
terepthalate, polyethylene butyrate and polyethylene napthalate,
polyamides such as polyhexamethylene adipamide, polyurethanes,
polycarbonates, and polyvinyl alcohol; and mixtures thereof.
7. A roof covering as set forth in claim 6, wherein the plastic
film comprises additives and/or pigments.
8. A roof covering as set forth in claim 1, wherein the film has a
greater than 60% solar reflectance per ASTM E1918-97 and ASTM
E903-96.
9. A roof covering as set forth in claim 8, wherein the film has an
about 80% or greater solar reflectance per ASTM E1918-97 and ASTM
E903-96.
10. A roof covering as set forth in claim 8, wherein the film has a
greater than 60% thermal emittance per ASTM E408-71.
11. A roof covering as set forth in claim 10, wherein the film has
an about 90% or greater thermal emittance per ASTM E408-71.
12. A roof covering as set forth in claim 9, wherein the film has
self-cleaning characteristics such that it maintains greater than
65% solar reflectance after three years.
13. A roof covering as set forth in claim 12, wherein the film has
a self-cleaning top coat.
14. A roof covering as set forth in claim 12, wherein the film has
a photocatalyst coating.
15. A roof covering as set forth in claim 14, wherein the film has
titania (TiO.sub.2) as a photocatalyst.
16. A roof covering as set forth in claim 8, wherein the film has
sufficient low-temperature flexibility to withstand temperatures
down to about -30.degree. F. without cracking or breaking.
17. A roof covering as set forth in claim 8, wherein the film has
suitable tensile and impact strength so as to withstand periodic
foot traffic and typical building movement.
18. A roof covering as set forth in claim 8, wherein the film has
suitable conformability under typical field conditions so as to
create tight fits over EPDM seams and patches.
19. A roof covering as set forth in claim 8, wherein the film has
long-term weatherability with UV resistance, exterior durability
including ozone resistance, minimal plasticizer (if present) of low
temperature flexibility and tensile & impact strength after
10,000 hours weather-o-meter exposure.
20. A roof covering as set forth in claim 1, wherein the adhesive
comprises a pressure-sensitive adhesive.
21. A roof covering as set forth in claim 20, wherein the adhesive
is applied at about 15-60 gsm to the lower film surface.
22. A roof covering as set forth in claim 1, wherein the adhesive
is installation-compatible with about 40-110.degree. F. ambient
temperatures and/or with roof surface temperatures up to
175.degree. F.
23. A roof covering as set forth in claim 1, wherein the adhesive
has an initial peel strength (tack) so as to provide a sufficient
bond, but still allow for adhesive repositionability for
elimination of wrinkles.
24. A roof covering as set forth in claim 1, wherein the adhesive
has aged peel and sheer values (after 12-72 hours) so as to provide
sufficient adhesion over EPDM that has been pressure-washed clean
of loose inorganic material, dirt, and oils.
25. A roof covering as set forth in claim 1, wherein the adhesive
is suitable for a operating temperature range of -20.degree. F. to
180.degree. F.
26. A roof covering as set forth in claim 1, wherein the adhesive
has the ability to resist ponding or standing water by maintaining
suitable adhesion when exposed to water.
27. A roof covering as set forth in claim 1, wherein the adhesive
substantially completely covers the second surface of the film.
28. A roof covering as set forth in claim 1, wherein the adhesive
is applied in a pattern that does not substantially completely
cover the second surface of the film.
29. A roof covering as set forth in claim 28, wherein the pattern
is a continuous pattern.
30. A roof covering as set forth in claim 28, wherein the pattern
is a discontinuous pattern.
31. A roof covering as set forth in claim 28, wherein the pattern
essentially consists of a random arrangement of adhesive and/or a
random arrangement of adhesive voids.
32. A roof covering as set forth in claim 1, further comprising a
release coating on the first surface of the film.
33. A roof covering as set forth in claim 32, wherein the release
coating is a silicone-based release coating.
34. A roof covering as set forth in claim 32, wherein the release
coating allows a sufficient release force to facilitate separation
and installation from a wound roll while still providing a minimum
bond between overlapping adjacent sheets.
35. A roof covering as set forth in claim 32, wherein the release
coating has a dry coefficient of friction that safely allows
periodic roof foot traffic.
36. A roof covering as set forth in claim 32, wherein the release
coating has long-term weatherability with UV resistance and
exterior durability (including ozone resistance) after 10,000 hours
weather-o-meter exposure.
37. A roof covering as set forth in claim 32, further comprising a
temporary liner positioned over the release coating, the temporary
liner and the release coating being removed prior to
installation.
38. A roof covering as set forth in claim 1, wherein the covering
is provided on a roll and has an unrolled length of at least ten
times its width.
39. A roof covering as set forth in claim 1, wherein the covering
is provided in sheets having a length within 20% of the width,
about the same as the width, or longer than the width.
40. A roof covering as set forth in claim 39, wherein the sheets
have a substantially rectangular shape.
41. A roof covering as set forth in claim 1, further comprising a
removable liner temporarily attached to the adhesive and removable
therefrom prior to installation on the roof.
42. In combination, a roof covering as set forth in claim 1 and a
roof, the adhesive being adhered to the top surface of the
roof.
43. The combination set forth in claim 42, wherein the roof
comprises a EPDM membrane and wherein the roof covering is adhered
to the EPDM membrane.
44. The combination set forth in claim 43, wherein the roof
covering is adhered to the EPDM membrane after the EPDM membrane is
assembled to the roof.
45. The combination set forth in claim 44, wherein the roof
covering is adhered to the EPDM membrane prior to the EPDM membrane
being assembled to the roof.
46. A method of covering a roof, said method comprising the steps
of: assembling an EPDM membrane to a roof structure; and adhering
the roof covering of claim 1 to the EPDM membrane.
47. A method as set forth in claim 46, wherein said adhering step
is performed after said assembling step.
48. A method as set forth in claim 46, wherein said adhering step
is performed prior to said assembling step.
Description
RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C.
.sctn.119(e) to U.S. Provisional Patent Application No. 60/496,099
filed on Aug. 18, 2003, and of Provisional Patent Application No.
60/474,970 filed on Jun. 2, 2003. The entire disclosures of these
earlier applications are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally, as indicated, to a
roof wrap and, more particularly, to a material used for covering
EPDM (black rubber) membranes on low-slope roofs.
BACKGROUND OF THE INVENTION
[0003] During the last several years, the U.S. Environmental
Protection Agency (EPA), U.S. Department of Energy (DOE), major
energy service providers (electric utility companies), utility
regulatory agencies, air quality management officials, and the
roofing industry have increasingly focused on the energy efficiency
impact of alternative roof designs. Research at national
laboratories and actual construction installations have shown that
certain types of roofs that have high solar reflectance and that
readily release or emit any absorbed heat can reduce summertime
peak roof surface temperatures by over 50.degree. F. and often cut
air conditioning loads by over 20%. These roofs have come to be
called "cool roofs."
[0004] Cool roofs can translate into significant savings to
building owners, especially since such roofs have the greatest
impact during summertime peak use periods when electricity rates
are often highest. Utilities generally welcome reductions during
peak periods, as this helps to avoid overloads to generation
capacity (and in the worst case, rolling blackouts). Flattened peak
demand also allows energy service providers to delay power plant
expansions, run at higher overall capacity utilization, and deliver
a greater return to utility shareholders. Additionally, the EPA
welcomes the reduction of greenhouse gas emissions related to
reduced power generation.
[0005] The EPA also sees cool roofs as a key tactic for the
reduction of the "Urban Heat Island" effect that is now occurring
in many cities. Specifically, in these cities the increase in
heat-absorbing roofs, dark parking lots, and road systems in place
of trees and vegetation has caused urban areas to be several
degrees warmer than the surrounding countryside. Higher summertime
temperatures rapidly accelerate the photochemical reactions that
generate smog. For example, in Los Angeles each degree increase in
temperature above 70.degree. F. increases smog generation by 3%.
Studies show that transitioning to more cool roofs, lighter
pavement, and more urban greenery could have dramatic effects on
the air quality of many cities. Beyond these air quality benefits,
cool roofs often reduce thermal stresses on roof systems and block
harmful UV rays that prematurely degrade conventional asphalt
roofing. Thus, cool roofs can help extend roof life, thereby
reducing the need for reroofing and consequently decreasing
landfill waste.
[0006] The late 1990's witnessed a major trend towards cool roofs
in non-residential building, with states such as Georgia, Florida,
and California taking the lead through building energy code
changes. In 1999, the U.S. EPA launched an ENERGY STAR.RTM. program
for roofing (www.energystar.gov). In 2001-2002, California offered
rebates for cool roof installations, and by 2005 cool roofs may be
mandated in California. In January 2003, the Cool Roof Rating
Council (www.coolroofs.org) started its Product Rating Program,
which the industry expects will become the key reference database
for future ENERGY STAR.RTM., state and local utility programs.
[0007] Today's commercially-available Cool Roofs fall into two
basic categories: thermoplastic single ply membranes and
fluid-applied (coating) systems. Regarding single ply membranes,
TPO and PVC (factory-produced 45-80 mil reinforced sheets of
formulated thermoplastics), which are installed with mechanical
fasteners, adhesives, and heat welding on low-slope roofs, are the
leading candidates. Regarding fluid-applied systems, water-based
acrylic elastomeric coatings dominate this segment, and are
installed in conjunction with other roofing components so as to
provide roof waterproofing or are installed over many existing roof
types so as to preserve those roofs from sun degradation and
premature failure.
[0008] Among conventional low-slope roof types, EPDM (rubber)
membranes have long maintained a major market share. EPDM is
cost-effective to install, has proven long-term durability, and has
widely been accepted by leading roofing contractors, key
architects, and specifiers. Presently, there is believed to be over
10 billion square feet of installed black EPDM roofing and, thus,
these roofs represent a very large opportunityforthe conversion of
non-residential building roofs to more energy-efficient cool roofs.
In fact, several roofing manufacturers and contractors are
currently seeing high growth in EPDM restoration with fluid-applied
"cool roof" coatings.
[0009] The presently-used coatings for EPDM roofs appear to reduce
the air conditioning load on buildings, significantly improve
building comfort in non-conditioned spaces, and eliminate peak
200.degree. F. temperatures and associated high thermal stresses
that lead to seam failures and damage at key wall and penetration
junctures. However, these coatings are not without disadvantages.
As a specific example, acrylic coatings have generally low adhesion
to the EPDM material. Also, surface preparation requirements
involve multiple washings and chemical additives to thoroughly
clean and condition the EPDM in order to improve bonding of the
coatings. (Surface preparation alone can cost $0.20 per square
foot.) Additionally, a significant coverage of the coating is
required in order to achieve minimum adhesion and mechanical
properties of the elastomeric coating (usually a minimum of 15 dry
mils of coating, which converts to $0.30-$0.50 per square foot in
coating and related materials costs). Further, two-pass coating
applications are necessary due to the curing requirements of
water-based coatings and the overall dry mils required. Still
further, the marked-up labor needed to install coating systems is
expensive (it often exceeds $0.50 per square foot), in that special
equipment (e.g., airless spray rigs) requires skilled labor (e.g.,
trained spray mechanics). Moreover, because of drying/curing
requirements and/or overspray risks, there are frequent
environmental constraints on application time due to low
temperatures, high humidity, near-term inclement weather, and high
winds.
SUMMARY OF THE INVENTION
[0010] The present invention provides a cost-effective cool-roof
covering for EPDM roofs that eliminates the disadvantages
associated with conventional coating techniques. Specifically, the
covering requires less membrane cleaning/preparation to achieve
sufficient adhesion, provides more uniform adhesion to the entire
roof, is less susceptible to localized de-lamination and failure,
does not require special spray equipment and/or highly skilled
spray mechanics, can be installed over a much broader
temperature/humidity range, requires less cure time prior to being
exposed to rain and dew, and can be installed faster and cheaper
than two-pass coating applications. Moreover, the covering can be
made in the form of a uniform thickness, factory-produced
protective film.
[0011] More particularly, the present invention provides a roof
covering comprising a plastic film and an adhesive positioned under
the lower film surface. The film can be a plastic film selected to
provide substantial solar reflectance and high thermal emittance.
The adhesive can be a pressure-sensitive adhesive and can be
selected to be installation-compatible with about 40-110.degree. F.
ambienttemperatures and/or with roof surface temperatures up to
175.degree. F., and to provide sufficient adhesion to water-cleaned
EPDM membranes. The roof covering of the present invention can be
provided in a roll, sheets, or other medium and it can be
factory-produced through the utilization of current high-speed,
wide-web coating manufacturing processes to yield self-wound
rolls.
[0012] These and other features of the invention are fully
described and particularly pointed out in the claims. The following
description and drawings set forth in detail certain illustrative
embodiments of the invention, which are indicative of but a few of
the various ways in which the principles of the invention may be
employed.
DRAWINGS
[0013] FIG. 1 is a front view of a building with the cool-roof
covering according to the present invention installed thereon.
[0014] FIG. 2A is a top view of the building with the cool-roof
covering being applied in a certain manner.
[0015] FIG. 2B is another top view of the building with the
cool-roof covering being applied in another manner.
[0016] FIG. 3A is a perspective view of a roll of the cool-roof
covering.
[0017] FIG. 3B is a perspective view of a stack of the cool-roof
covering.
[0018] FIG. 4 is a sectional view of the cool-roof covering, the
covering comprising a film and an adhesive positioned on the lower
surface of the film.
[0019] FIG. 5 is a sectional view of the cool-roof covering with a
photocatalystic coating positioned over the upper surface of the
film.
[0020] FIG. 6 is a sectional view of the cool-roof covering with a
temporary liner positioned over the adhesive.
[0021] FIG. 7 is a sectional view of the cool-roof covering with a
release coating positioned over the film.
[0022] FIG. 8 is a sectional view of a laminate incorporating the
cool-roof covering and a EPDM membrane.
DETAILED DESCRIPTION
[0023] Referring now to the drawings, and initially to FIG. 1, the
cool-roof covering 10 according to the present invention is shown
on a residential or commercial building 12. The building 12 has a
low slope roof 14 (e.g., 0.degree. to about 10.degree.) comprising
metal structural members 16, wooden plats 18 placed on top of the
members 16, and an EPDM rubber membrane 20 on top of the plats 18.
(Other members, such as insulation board, can also be included in
the roof structure.) The cool-roof covering 10 is adhered to the
rubber membrane 20.
[0024] As is shown in FIG. 2A, the covering 10 can be applied in
strips running the length of the roof 14. Alternatively, of course,
the strips could be positioned to run the width of the roof 14. In
either or any event, the cool-roof covering 10 can be provided in a
roll 30 as shown in FIG. 3 and provided in widths of, for example,
at least 2 feet and, more particularly, from about 30 to about 150
inches. With particular reference to EPDM rubber membrane
applications, the widths could correspond to the dimensions of the
rubber membranes 20, such as, for example, 10 feet or 12 feet. The
roll can be a suitable length for transportation and/or
installation purposes, such as 150 feet long.
[0025] As shown in FIG. 2B, the covering 10 can be applied in
rectangular sections, and these can be provided in a stack 32 such
as that shown in FIG. 4. The rectangular sections can have a width
W of about one foot, greater than one foot, and/or greater than two
feet, and a length L within 20% of the width, within 30% of the
width, within 50% of the width, about the same as the width, or
longer than the width. Sections having a rectangular shape often
are the most compatible with roofing applications, and the size is
selected to accommodate transportation and/or installation
purposes. That being said, other non-rectangular shapes (e.g.,
triangular, curved-sides) are possible with and contemplated by the
present invention.
[0026] Whether the covering 10 is provided in a roll, sheets, or
other medium, it can be factory-produced through the utilization of
current high-speed, wide-web coating manufacturing processes to
yield self-wound rolls, linered pressure sensitive adhesive
articles, and/or membrane-laminates.
[0027] If the covering 10 will be installed in strips (FIG. 2A),
the roll 30 can be shipped to the construction site ready for
installation on cleaned EPDM roofs. When the covering 10 is
provided in roll form, it usually has an unrolled length of at
least about ten times its width, at least about twenty times its
width, and/or at least about thirty times its width. If the
covering 10 is to be provided in a stack, a similar process can be
used to produce a continuous length of material having a width
equal to the desired width of the sections and then automatically
separate it into sheets of the desired length.
[0028] Referring now to FIG. 4, the cool-roof covering 10 is
illustrated in detail isolated from the rest of the roof. As shown,
the covering 10 comprises a plastic film 40 having a first (upper)
surface 42 and a second (lower) surface 44, and an adhesive 46
positioned under the lower film surface 44. Preferably, the
adhesive 46 is factory-applied to the plastic film at line speeds
of 150-3000 feet per minute through the use of various high speed,
wide web coating technologies (e.g., gravure, roll, knife,
extrusion die, etc.). This translates into lower assembly costs
and, therefore, lower costs versus conventional high performance
coatings. Also, a factory-applied process results in greater
consistency in protective film thicknesses and mechanical
properties per pre-determined incoming plastic film specifications.
Furthermore, such a process offers tighter control over the
application rates of the pressure-sensitive adhesive 46. It may be
noted that such tight control is essentially impossible when
adhesive or roof coatings are applied at the time of installation
by a roofer. The plastic film 40 can have a thickness in the range
of about 3 to about 50 mils thick and a width equal to that of the
roll 30 (e.g., typical widths would be in the range of about 30 to
about 80 inches). Suitable plastic films include acrylics such as
poly(methyl methacrylate) and poly(ethyl methacrylate),
polystyrenes such as poly(p-styrene) and syndiotactic polystyrene,
and styrene-based copolymers, vinylic such as polyvinyl chloride,
polyvinylicene chloride, polyvinylidene fluoride and polyvinylidone
dichloride, polyolefin homopolymers such as polyethylene and
polypropylene, copolymers of ethylene, propylene and/or butylene,
copolymers containing ethylene such as ethylene vinyl acetate,
ethylene acrylic acid and ethylene methacrylate copolymer,
polyesters such as polyethylene terephthalate, polyethylene
butyrate and polyethylene napthalate, polyamides such as
polyhexamethylene adipamide, polyurethanes, polycarbonates, and
polyvinyl alcohol; and mixtures thereof.
[0029] Preferably, the plastic film 40 has a greater than 60% solar
reflectance, and preferably about an 80% solar reflectance, per
ASTM E1918-97 and ASTM E903-96 and greater than 60% thermal
emittance, and preferably about 90% thermal emittance, per ASTM
E408-71. The plastic film 40 preferably also provides sufficient
low-temperature flexibility so as to be able to withstand
temperatures down to about -30.degree. F. without cracking or
breaking, and suitable tensile and impact strength so as to be able
to withstand periodic foot traffic and typical building movement.
Self-cleaning characteristics can also be important to maintain
greater than 65% solar reflectance after three years. The plastic
film 40 can also preferably display suitable conformability under
typical field conditions (e.g., involving modest brush pressure) to
create tight fits over EPDM seams and patches. Long-term
weatherability with UV resistance, exterior durability including
ozone resistance, minimal plasticizer (if present) of low
temperature flexibility and tensile & impact strength after
10,000 hours weather-o-meter exposure, are also desirable
features.
[0030] The adhesive 46 can be a pressure-sensitive adhesive applied
at 15-60 gsm to the lower film surface 44. Preferably, the adhesive
46 is installation-compatible with about 40-110.degree. F. ambient
temperatures and with roof surface temperatures up to 175.degree.
F. Its initial peel strength (or tack) should provide a sufficient
bond, but also allow for adhesive repositionability for the
elimination of wrinkles. Further the adhesive 46 preferably has
aged peel and sheer values (after 12-72 hours) to provide
sufficient adhesion over EPDM that has been pressure-washed (water)
to clean off loose inorganic material (e.g., mica), dirt, and oils
and is suitable for an operating temperature range of -20.degree.
F. to 180.degree. F. The adhesive 46 further preferably has the
ability to resist ponding or standing water by maintaining suitable
adhesion when exposed to water.
[0031] The adhesive 46 can substantially cover the surface 44 or it
can be patterned thereover. For example, the pattern can comprise a
patchwork pattern of unconnected squares, smooth or sharp sine
waves, and/or a honeycomb design having cells positioned in aligned
or offset rows. The pattern can be as simple as a series of dots or
a series of longitudinally-extending stripes. The pattern can have
a random positioning of voids. Accordingly, the pattern of the
adhesive 46 can comprise a continuous or discontinuous network of
geometric shapes.
[0032] Referring now to FIG. 5, the cool-roof covering 10 can
further comprise a photocatalyst coating 48. The coating 48 can
preferably comprise a coating with titania (TiO.sub.2) as a
photocatalyst having a decomposing function including deodorizing,
antibacterial and soil-resisting actions, and also a hydrophilic
function. Photocatalysts containing as the major component titania
having excellent decomposing and hydrophilic functions have been
utilized conventionally in many fields. Irradiation of ultraviolet
light contained in the sunlight or fluorescent light upon titania
causes generation of electrons and positive holes on the titania
surface, and the electrons reduce the atmospheric oxygen into super
oxide ions (O.sub.2), whereas the positive holes oxidize the
moisture deposited on the titania surface into hydroxyl group
radicals (OH). These superoxide ions and hydroxyl group radicals
carry out oxidative decomposition of organic compounds including
soil and the like present on the titania surface. As was indicated
above, self-cleaning characteristics can also be important to
maintain greater than 65% solar reflectance after three years.
[0033] Referring now to FIG. 6, the covering 10 can further
comprise a removable liner 50, which is temporarily attached to the
adhesive 46 and removable therefrom prior to installation. This
liner 50 can comprise a paper or plastic film, which is easily
removed from the adhesive 46 and allows the covering 10 to be
provided in roll form (FIG. 3A) and/or stack form (FIG. 3B).
[0034] Referring now to FIG. 7, the covering 10 can comprise a
release coating 52 over the first (upper) surface 42 of the film
40. The release coating 52 can be a silicone-based release coating
and, in any event, preferably allows a sufficient release force to
facilitate separation and installation from a wound roll (e.g.,
FIG. 3A) or a stacked pile (e.g., FIG. 3B). The release coating 52
preferably has a dry coefficient of friction that safely allows
periodic roof foot traffic, which may be accomplished, for example,
by texturing. The coating 52 also preferably has long-term
weatherability with UV resistance and exterior durability
(including ozone resistance) after 10,000 hours weather-o-meter
exposure. If the release coating 52 will remain with the roof
covering 10 after installation, and if it is to be used for
seam-bonding purposes, the coating must strike a balance between
sufficient installation separation and adequate seam bonds. (One
alternative is not to depend upon the overlapping of sections for
bonding purposes and to instead use tape or other sealing strips to
seal the joints between adjacent sections of the covering 10.) The
roof wrap covering 10 can be installed after the EPDM membranes 20
are assembled on the plats 18 or otherwise assembled onto the roof
14. Alternatively, as is shown in FIG. 8, the roof wrap covering 10
can be adhered to the EPDM membranes 20 prior to assembly of these
membranes. In this manner, the installation of the roof wrap
covering and the EPDM membranes can be accomplished in a single
step and provided in laminate form.
[0035] It may now be appreciated that the cool roof covering 10 of
the present invention greatly reduces installation time, cost, and
complications when compared to conventional cool roof products. The
covering 10 can arrive ready-to-install at a work site, and
application of film rolls can be achieved through the use of simple
roll carts, brush applicators, and cutting tools. There is no need
for more complex and costly application equipment, such as
specialized spray rigs, as well as the need for trained spray
mechanics. Installation can be accomplished in a single pass
(versus two passes with conventional elastomeric coatings over one
or more days). Also, the cool roof covering can be used by
do-it-yourself home owners, something that would be almost
impossible with conventional cool roof products.
[0036] The cool roof covering 10 also eases installation by
eliminating some conventional set-up procedures. As a specific
example, the covering 10 allows for fully-adhered coverage over
EPDM membranes that are cleaned with only high-pressure water
washing techniques without the need for special cleaning and
membrane conditioning chemicals. This roofing product also avoids
the extra set-up time commonly dedicated to preventing overspray
and odors, as these cause occupant concerns when the sprayed
coatings creep into the building's HVAC and vent systems.
[0037] The cool roof covering 10 further provides an increased
degree of customized installation, with the ability to incorporate
high performance taping of EPDM seams, double or triple film
applications in high traffic areas, for example. Installers can
monitor quality in real time by visually noting film application,
wrinkling, and other factors.
[0038] It may also now be appreciated that the cool roof covering
10 provides a consistency not found in other cool roof products.
Because the adhesive 46 is applied prior to the work site, the roof
covering 10 eliminates the variability and risk associated with
numerous commercially available acrylic coatings that differ in
formulation, adhesion characteristics, and long-term exterior
durability. The cool roof covering 10 also avoids the variability
and risk associated with inconsistent wet coating thicknesses and
the impact such inconsistency has on coating cure time and final
coating film integrity and performance.
[0039] It may further be noted that weather and dependence upon
weather reports is minimized with the cool roof covering 10 of the
present invention. Specifically, the cool roof covering 10 permits
EPDM installation in colder temperatures, higher humidity, and
within a few hours of inclement weather. In comparison, most
acrylic coatings must be installed above 50.degree. F. and allowed
to dry and cure for days prior to precipitation.
[0040] Although the invention has been shown and described with
respect to certain preferred embodiments, it is evident that
equivalent and obvious alterations and modifications will occur to
others skilled in the art upon the reading and understanding of
this specification. For example, the roof covering need not be
limited to solar-reflecting situations (e.g., "cool roofs") but
instead could be modified to include other characteristics needed
in a particular roofing application. The present invention includes
all such alterations and modifications and is limited only by the
scope of the following claims.
* * * * *