Patent Application
20090022924
1. Field of Art
The present invention relates to a roofing patch. More specifically, the present invention relates to a roofing patch which is effectively self-adhering and is useful for repairs and sealing “T-joints”.
2. Description of the Related Art
Conventional single ply and modified bitumen roof coverings or membranes, in use since 1970, have experienced several problems involving ease of installation, poor light reflectivity resulting in higher energy costs, and shrinkage resulting in seam failure, low tolerance of cold temperatures causing cracking and loss of flexibility and lower adhesive resistance to chemical attack. All resulting in the need for replacement and/or repair. Conventional roofing employing single ply sheets of ethylene/propylene/butadiene (EPDM) copolymers have experienced leakage and seam failure due to membrane shrinkage. The introduction of seam tapes replacing adhesives have partially ameliorated this condition; however, the application of tapes is time consuming and encounters difficulties in repair and replacement. In general, all single ply and modified bitumen roofs may need repair patches due to seam, lap or joint failure, cracking, mechanical damage, foot traffic, etc.
Ease of repair is a key requirement for any roofing membrane. The addition of rooftop equipment, mechanical damage from natural forces or human error can necessitate a repair to even the best roofing system. Accordingly, single ply and modified bitumen roofs at time will need repair, known as “patching”. New methods for patching such roof systems that are both easy and inexpensive as well as providing a patch that is as strong as the original membrane is required for membrane roof systems.
Single ply and modified bitumen roofing membranes (mechanically-attached or fully-adhered), as well as self-adhered SBS systems often require patches to be placed on “T-joints” to insure the joint stays watertight. Also, all roof systems sometimes need patches to be applied when repairs are made, or for additional penetrations etc. Such patches exist, but need labor to either hot-weld them, mix and apply adhesive, or hot asphalt, or torches. Sometimes T-joints or laps are caulked, which again requires additional labor and attention to detail.
U.S. Pat. No. 7,101,598 discloses a self adhering membrane for roofing application. The self adhering membrane includes a water impermeable membrane, a pressure sensitive, hot melt adhesive adhered to one side of the water impermeable membrane, and a release liner on the side of the pressure sensitive adhesive opposite the water impermeable membrane. The single ply self adhering roofing membrane is joined to the roof substrate by removing the release liner and then pressing the side of the membrane with the adhesive directly onto the roof substrate. How one would repair the membrane or seal a joint or seam is not discussed.
Accordingly, it is an object of the present invention to provide a patch for a roofing membrane which is quick, reliable and requires minimal tools and materials.
Provided is a patch for a roofing membrane, which comprises a substrate for application to the roofing membrane, with the substrate containing encapsulated adhesive on the side to be applied to the roofing membrane. The adhesive is encapsulated in rupturable cells which will rupture to release the adhesive when pressure is applied. The cells in which the adhesive is encapsulated preferably comprise multiple bubbles or multiple ribbons. Most preferably, the substrate of the patch is made from the same material as the initial roofing membrane, e.g., EPDM patch with EPDM compatible adhesive to repair an EPDM roof.
Also provided is a method of applying a patch to a roofing membrane, which comprises first providing the patch of the present invention, applying the patch to the desired portion of the roofing membrane, and applying sufficient pressure to the patch to rupture the cells containing the adhesive to thereby release the adhesive. The pressure can be applied with a tool, such as a roller, or simply by manual pressure.
Among other factors, the present invention provides a patch which allows quick, reliable patching for repairs, and for sealing seams and/or T-joints. By encapsulating the adhesive, which is compatible with the patch and the roofing membrane to form a good bond, in rupturable cells, the patch can be stored and easily applied when and where desired by simply applying the patch with pressure. Application of pressure ruptures the cells to thereby allow the release of the adhesive. The adhesive flows to fill-in all channels, holes, gaps, etc., which could provide sites for water ingression. The patch can be cut to the desired shape and size, and minimal tools and materials are required for its application.
The patch can be made of any standard roofing membrane material (e.g. SBS, PVC, TPO, EPDM etc), but preferably is of the same material as the roof membrane being patched. The patch can be any size or shape, the most commonly used are, for example, 8″×8″ or 12″×12″, but they can be different sizes and do not need to be square. For example, an elongated rectangular patch may be used to patch along a seam. The patches can also be circular.
If this patch is used as a “target” to go over an extending member on the roof, for example, a round roof vent penetration, the patch may have a hole in the center to go over the penetration.
Referring to
The underside of the patch, the side which will be bonded to the existing roofing membrane, contains adhesive encapsulated in rupturable cells, for example, in small bubbles. The cells may be made of plastic, such as polyethylene, but any suitable materials will work, as long as it ruptures relatively easily to release the adhesive when pressure is applied, and does not react or degrade when in contact with the adhesive. Preferably, the adhesive is in discrete bubbles, or may be in ribbons along the patch, as shown in
In
Each cell of adhesive may contain the same adhesive, which bonds the patch to the membrane. The adhesive may need to be different depending on the patch materials and the roofing membrane material. For example, for SBS systems, an adhesive used for bonding SBS adhesive will need to be used, or a TPO adhesive for TPO membranes. Alternatively, a 2-part adhesive may be used, where some bubbles will contain the part A adhesive and some of the part B. The ratio of A and B, or the size of the bubbles, will insure that the correct amounts of A and B are mixed.
On an area or T-joint or lap which needs to be patched, the patch of the appropriate size, either pre-cut or cut to size on the roof, or a hold cut in for a penetration, would be placed over the area and pressure applied on top, either by a roller or even by standing on the patch. This pressure would burst the bubbles enabling the adhesive to flow and bond the patch to the surface of the roofing membrane. Enough adhesive would be released to flow into any areas difficult to access, for example, into laps, T-joints, or even to flow around a granulated roofing surface ensuring the patch is completely watertight.
The roofing contractor would need only to take some patches onto the roof, maybe a roller and maybe a knife or scissors, to cut the patch to the desired size. The patch could be applied quickly and easily, saving time labor and insuring a leak-proof patch. Also, no solvents, applied adhesives, open flames, hot asphalt, etc. is needed or used in the simple application of the roof patch of the present invention.
While various embodiments have been described, it is to be understood that variations and modifications can be resorted to as will be apparent to those skilled in the art. Such variations and modifications are to be considered within the purview and scope of the claims appended hereto.
