U.S. patent application number 11/238371 was filed with the patent office on 2007-03-29 for rubberized roof underlayment.
This patent application is currently assigned to Northern Elastomeric, Inc.. Invention is credited to James A. Karlis, Thomas J. Zickell.
Application Number | 20070071946 11/238371 |
Document ID | / |
Family ID | 37894393 |
Filed Date | 2007-03-29 |
United States Patent
Application |
20070071946 |
Kind Code |
A1 |
Zickell; Thomas J. ; et
al. |
March 29, 2007 |
Rubberized roof underlayment
Abstract
An underlayment product comprises a fibrous mat having an upper
surface and a lower surface. A rubberized asphalt coating is
applied to the lower surface of the fibrous mat and extends at
least partially into the fibrous mat. An oxidized asphalt coating
is applied to the upper and lower surfaces of the fibrous mat
generally encapsulating the fibrous mat including the rubberized
asphalt coating provided on the lower surface of the fibrous mat.
The oxidized asphalt layers may be coated with a release layer such
as talc, granules or a polymer.
Inventors: |
Zickell; Thomas J.; (New
Castle, NH) ; Karlis; James A.; (Pelham, NH) |
Correspondence
Address: |
BOURQUE & ASSOCIATES;INTELLECTUAL PROPERTY ATTORNEYS, P.A.
835 HANOVER STREET
SUITE 301
MANCHESTER
NH
03104
US
|
Assignee: |
Northern Elastomeric, Inc.
Brentwood
NH
|
Family ID: |
37894393 |
Appl. No.: |
11/238371 |
Filed: |
September 29, 2005 |
Current U.S.
Class: |
428/143 |
Current CPC
Class: |
Y10T 428/24372 20150115;
E04D 12/002 20130101 |
Class at
Publication: |
428/143 |
International
Class: |
E01F 9/04 20060101
E01F009/04 |
Claims
1. An underlayment membrane comprising: a fibrous mat having an
upper surface and a lower surface; a rubberized asphalt coating
applied to the lower surface of the fibrous mat and extending at
least partially into said fibrous mat; and an oxidized asphalt
coating applied to said upper and lower surfaces of said fibrous
mat generally encapsulating said upper and lower surfaces of said
mat including said rubberized asphalt coating applied to the lower
surface of the fibrous mat.
2. The underlayment membrane of claim 1 further including a release
coating applied to said oxidized asphalt coating proximate said
upper and lower surfaces of said fibrous mat.
3. The underlayment membrane of claim 2 wherein said release
coating includes a talc coating.
4. The underlayment membrane of claim 2 wherein said release
coating includes granule particles applied proximate at least said
oxidized asphalt coating proximate said upper surface of said
fibrous mat.
5. The underlayment membrane of claim 2 wherein said release
coating includes a polymeric coating disposed on at least said
oxidized asphalt coating proximate said upper surface of said
fibrous mat.
6. The underlayment membrane of claim 5 wherein said polymeric
coating is provided with a coating of finally-ground mineral.
7. The underlayment membrane of claim 6 wherein said finally-ground
mineral includes talc.
8. The underlayment membrane of claim 6 wherein said finally-ground
mineral includes granules.
9. The underlayment membrane of claim 1 wherein said rubberized
asphalt coating includes approximately 46% flux asphalt, 4% rubber
and 50% filler material.
10. The underlayment membrane of claim 1 wherein the fibrous mat
includes fibers selected from the group consisting of polyesters,
polypropylenes and fiberglass.
11. An underlayment membrane comprising: a fibrous mat having an
upper surface and a lower surface; a rubberized asphalt coating
applied to the lower surface of the fibrous mat and extending at
least partially into said fibrous mat; an oxidized asphalt coating
applied to said upper and lower surfaces of said fibrous mat
generally encapsulating said upper and lower surfaces of said mat
including said rubberized asphalt coating applied to the lower
surface of the fibrous mat; and a release coating applied to said
oxidized asphalt coating proximate said upper and lower surfaces of
said fibrous mat.
12. An underlayment membrane comprising: a fibrous mat having an
upper surface and a lower surface; a rubberized asphalt coating
applied to the lower surface of the fibrous mat and extending only
partially into said fibrous mat; and an oxidized asphalt coating
applied to said upper and lower surfaces of said fibrous mat
generally encapsulating said upper and lower surfaces of said mat
including said rubberized asphalt coating applied to the lower
surface of the fibrous mat.
Description
TECHNICAL FIELD
[0001] The present invention relates to roof underlayments and more
particularly, to a heavyweight, underlayment product which utilizes
a rubberized asphalt layer.
BACKGROUND INFORMATION
[0002] An underlayment material is commonly used in a number of
roofing applications as well as other underlayment situations. The
typical product utilized in roofing underlayment is commonly
referred to as "tar" of "felt" paper. The traditional "tar paper"
is an asphalt impregnated paper product which is sold in a roll;
unrolled on a roof; cut to length; and fastened to the roof
utilizing staples or nails. Although tar paper is inexpensive, it
does not seal nail holes through the paper and thus does not
prevent water infiltration. In addition, once the felt is rolled
out, it absorbs water and once wet, it wrinkles and expands, and
must be allowed to dry out before covering with shingles. Other
prior art shingle underlayment products also suffer from the same
problems.
[0003] Accordingly, what is needed is a generally low cost,
heavyweight, dimensionally stable underlayment product on which the
installer can walk, without sticking or slipping, which will not
slide underfoot and which will cold flow and/or elongate and
recover to seal nail holes and other punctures. In addition, such a
product should be dimensionally stable, resist tearing,
non-adhesive to other layers, and provide hot and cold
flexibility.
SUMMARY
[0004] The present invention features a novel underlayment product
which will be relatively inexpensive and replace prior art products
such as "tar paper" or "felt paper". The present invention provides
an underlayment product with a top surface that can be walked on
and will not slide under foot, and wherein the product will not
stick to itself or the roof. In addition, the present invention has
"cold" flow properties which allow it to "repair" or "heal" itself
to thereby reseal around nail or puncture holes and also elongate
and recover around punctures.
[0005] In accordance with one embodiment of the present invention,
the underlayment includes an underlayment membrane comprising a
fibrous mat having an upper surface and a lower surface. An
elastomeric asphalt coating is applied to the lower surface of the
fibrous mat and at least partially or fully infiltrates and
saturates the fibrous mat. Next, an oxidized asphalt coating is
applied to both the upper and lower surfaces of the fibrous mat,
thereby essentially encapsulating the fibrous mat.
[0006] The underlayment membrane may further include a release
coating applied to the oxidized asphalt coating on either the upper
and/or lower surface of the fibrous mat. The release coating
includes, in one embodiment, a talc/water coating but may
alternatively include granule particles applied proximate at least
the oxidized asphalt coating proximate said upper surface of said
fibrous mat.
[0007] The release coating may include a polymeric coating applied
on at least the upper surface of the fibrous mat while the
polymeric coating may be provided with a coating of finally-ground
mineral, such as talc and finely-ground granules.
[0008] In the preferred embodiment, the rubberized asphalt coating
which is applied from the bottom of the mat and partially or fully
infiltrates the fibrous mat includes approximately 48% flux
asphalt, 2% radial SBS rubber and 50% filler material while the
fibrous mat includes fibers selected from the group consisting of
polyesters, polypropylenes and fiberglass. The coating may,
however, be provided having a range a ingredients including, but
not limited to 0.5% to 12% radial or linear rubber or polymer;
0-70% filler; and 48-98% asphalt including 0-70% oxidized asphalt.
The filler affects the walkability of the outer surface. If the
filler content is too low such that a higher asphalt percentage
exists, the product would be sticky. The high filler content and/or
talc layer prevents sticking. In addition, the filler also brings
down the price of the finished product.
[0009] Adding an oxidized asphalt layer on both the top and bottom
layer of the mat makes the product more usable in hotter conditions
providing a higher resistance to softening by providing an asphalt
with a higher Ring and Ball softening point temperature. It also
makes the product not stick in three ways: 1) foot traffic 2) the
roof deck and 3) in the roll form.
[0010] The rubber or other elastomer in the elastomeric layer may
be linear or radial rubber although with linear SBS rubber, as much
as 10 or 12 percent may be required whereas with radial SBS rubber,
0.5 to 6% will generally suffice.
[0011] In the preferred embodiment, the talc coating is suspended
in a water-based, polymer emulsion. Examples of the polymer include
styrene, acrylic and the polyurethane. When it dries, the polymer
forms a film which helps hold the talc to the asphalt so that the
talc does not fall off or interfere with any overlap or bonding
areas. Loose talc is a slip problem. Although a talc acrylic layer
is preferred as the method to prevent sticking, a water or other
based polymer may be applied and may be sufficient, as would be a
plastic film.
[0012] It is important to note that the present invention is not
intended to be limited to a system or method which must satisfy one
or more of any stated objects or features of the invention. It is
also important to note that the present invention is not limited to
the preferred, exemplary, or primary embodiment(s) described
herein. Modifications and substitutions by one of ordinary skill in
the art are considered to be within the scope of the present
invention, which is not to be limited except by allowed claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] These and other features and advantages of the present
invention will be better understood by reading the following
detailed description, taken together with the drawings wherein:
[0014] FIG. 1 is a schematic sectional view of the underlayment of
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The present invention features a novel underlayment product
which will be relatively inexpensive and replace prior art products
such as "tar paper" or "felt paper". The present invention provides
an underlayment product with a top surface that can be walked on
and will not slide under foot, and wherein the product will not
stick to itself or the roof. In addition, the present invention has
"cold" flow properties and elongate and recovery properties which
allow it to reseal around nail or puncture holes.
[0016] The underlayment 10, FIG. 1, in accordance with the present
invention includes a fibrous mat 12 disposed in the center of the
underlayment. Examples of and equivalents for the fibrous mat 12
are disclosed in U.S. Pat. Nos. 6,531,200 and 6,296,912 assigned to
the assignee of the present invention and incorporated fully herein
by reference.
[0017] The fibrous mat 12 is first coated proximate one side with a
rubberized asphalt layer 14. The rubberized asphalt layer 14
typically comprises approximately 4% rubber, 46% flux asphalt and
50% filler, although various percentages may be provided. These
percentages are approximate and those skilled in the art would
understand that a deviation from these percentages is considered
within the scope of the present invention.
[0018] The rubberized asphalt layer 14 exhibits "cold flow" or
"self-healing" properties by virtue of the inclusion of a
relatively small percentage of rubber. Accordingly, when the
underlayment 10 is punctured, such as by a nail, the rubberized
asphalt layer 14 will "self-heal" around the puncture thereby
resealing around the puncture. This is particularly important when
underlayment is used under roofing tile in which case the tiles are
fastened to the roof using "ring" nails which create a hole which
is larger than the nail shank itself. In this case, the rubber in
the underlayment will actually stick to the ridges in the nail
shank and stretch around the nail shank thereby creating a
generally watertight seal around the shank of the nail. Without the
"self-healing" properties of the rubberized asphalt layer 14 of the
underlayment 10 of the present invention, persistent roof leaks
abound.
[0019] In the preferred embodiment, the rubber includes "SBS"
radial rubber although linear rubber, in a higher content
percentage, would also be acceptable. The SBS rubber is mixed with
the flux asphalt using a high shear mill, as is well known in the
art. The rubberized asphalt layer 14 is applied to only one side of
the fibrous mat 12. This one-sided application serves to vaporize
and drive out any moisture trapped in the fibrous mat 12. Examples
of how to coat fibrous mats on one side can be found in the two
referenced United States patents previously fully incorporated by
reference.
[0020] The rubberized asphalt layer 14 infiltrates at least
partially but also can extend fully into the central region 13 of
fibrous mat 12.
[0021] After the application of the rubberized asphalt layer 14 to
one side of the fibrous mat 12, oxidized asphalt layers 16a and 16b
are applied; with oxidized asphalt layer 16a applied over the
rubberized asphalt layer 14 while the oxidized asphalt layer 16b is
applied directly to the fibrous mat on the side opposite the
rubberized asphalt layer 14. Accordingly, in the preferred
embodiment, the interface between the rubberized asphalt layer 14
and the oxidized asphalt layer 16b will occur in region 13 of
fibrous mat 12 and not proximate or on the upper surface 15 of
fibrous mat 12. If the interface between the oxidized asphalt layer
16b and the rubberized asphalt layer 14 is proximate or at the
upper surface 15 of fibrous mat 12, the oxidized asphalt layer 16
exhibits a tendency to slip or shear away from the rubberized
asphalt layer particularly due to foot traffic when the product was
installed on a hot roof. This presents a dangerous situation and
also one where the product would have a tendency to adhere to an
adjacent layer.
[0022] As is well known in the prior art, an oxidized asphalt layer
typically includes approximately 50% oxidized asphalt and 50%
filler. The oxidized asphalt layer 16b will become the top surface
of the underlayment 10. Since there is no rubberized asphalt layer
under the oxidized asphalt layer 16b, anyone walking on this
product will not slip given the propensity of oxidized asphalt
layer to break away from the rubberized asphalt layer if the
rubberized asphalt later were located directly beneath the top
oxidized asphalt layer and not within the fibrous mat 12.
[0023] Finally, the top and bottom of the underlayment 10 is coated
with a talc acrylic layer 18. The talc acrylic layer 18 provides an
additional coating to the oxidized asphalt layers, filling in any
voids that are present and preventing the membrane from sticking to
itself when the rolled. The talc layer 18 is applied as a
talc/water or talc polymer mixture as described, for example, in
U.S. Pat. No. 6,531,200. In an alternative embodiment, talc layer
18a may be replaced with or include granular particles.
[0024] Accordingly, the present invention provides a novel and
useful underlayment product which can be used under many roofing or
other materials as a substrate or underlayment, in which serves to
self-seal around any penetrations such as nails and the like.
[0025] As mentioned above, the present invention is not intended to
be limited to a system or method which must satisfy one or more of
any stated or implied object or feature of the invention and should
not be limited to the preferred, exemplary, or primary
embodiment(s) described herein. Modifications and substitutions by
one of ordinary skill in the art are considered to be within the
scope of the present invention, which is not to be limited except
by the allowed claims.
* * * * *