The present invention relates to roofing systems.
Rigid foam panels for providing a roofing membrane layer are currently available for use as an insulating underlayment in roof construction. Typically these are 4′ by 8′ (1.22 m by 2.44 m) panels 1.5″ (3.8 cm) thick made of a 1.6 pound per cubic foot polyurethane foam with a tar paper top layer. Such a material is not crush resistant enough to be used as a roof surface material and can also be easily punctured.
Core panels are common in the art and may be used in conjunction with a roof membrane layer. The functions of core panels include providing a fireproofing layer; providing a thermal barrier; providing a solvent barrier or moisture barrier; and providing an air barrier. One form of core paneling is a fiberglass-faced asphaltic board. Asphaltic boards are known to provide adequate moisture resistance, but may not serve as a fire barrier.
A second type of core panel is a semi-rigid rock wool or fiberglass. Boards of this type are permeable to moisture, provide little impact resistance, and do not provide a fire barrier.
A third type of core panel known in the art is a plywood, or veneer, sheet. Veneer sheets are combustible, however. Further, plywood sheets lose strength when wet, yet provide adequate strength for foot traffic.
A fourth type of core panel is a wood fiberboard, comprising organic fibers bonded with resin. Fiberboard is also combustible and loses strength when wet. Fiberboard provides at least some foot traffic protection, but crumbles when wet.
A fifth type of core panel is perlite, comprising a mineral aggregate board with cellulose binders and sizing agents. A perlite core panel may be used as a fire barrier. However, perlite core panels may fall apart when wet and are crushed by foot traffic.
A sixth type of core panel is a panel comprising a gypsum core with paper facers on each side. Paper-faced gypsum boards may be used in fire protection and provide moderate resistance to foot traffic. However, the paper facers may delaminate when wet.
In addition to the common type of core panels mentioned above, improved core panels exist providing properties specific to use. One example of an improved core panel is the Dens-Deck® Roof Board. This Roof Board comprises a high-density gypsum core and fiberglass mats embedded on both sides. The Roof Board may include a fireproofing layer, which may be as thin as ¼ inch. Such core panels may neither delaminate with moisture nor support mold growth. Furthermore, Roof Boards may support foot traffic and resist hail.
More specifically, core panels as described herein serve to support a roofing membrane and may be structurally located beneath a roofing membrane. The roofing membrane may adhere to the Dens-Deck® Roof Board directly. Typically, the edges of the Dens-Deck Roof Board should be butted together. However, for the condition of high gain in surface temperature, slight gaps may be required.
Optionally, a separating material may be used between the core panel and the roofing membrane. Further, several methods known in the art may be utilized to bond the separated core panels. One such method is known as “hot-mopping.” A second method of bonding core panels is known as “torching.” Torching may involve the application of a bitumen membrane, such as a “Dibiter APP modified bitumen member,” atop the core panels. The bitumen membrane, or “flashing member,” may then be positioned by the application of a heat-welding technique.
It is therefore an object of the present invention to provide a sturdy, weatherproof seamless roofing system that uses rigid foam boards or panels to create a seamless waterproof roof.
The roofing panels of this invention differ from the prior art underlayment product in several respects. The panels of this invention are:
The higher density affords more crush resistance, while the well bonded top layer resists punctures and provides a better adhesion surface for elastomeric top coats.
The roofing panels are bonded to roof substrate with low rise foam polyurethane adhesive which seeps through loose tongue-in-groove joints to form a blob at the top, which is shaved off and covered with a fabric top layer.
After the adhesive cures, a very secure bond between the panels results.
The low-rise foam adhesive is a two-part mixture that has distinct phases after mixing. By varying the formulations of the two parts, the “cream time” (i.e.—to achieve the consistency of shaving cream) as well as the “tack free” time can be controlled.
The panels are placed on the foam just after cream consistency and well before tack-free time so that the foam rises through the joints. After the adhesive cures to a solid consistency, the blobs are removed from all of the joints. This is typically accomplished by grinding using a disk pad grinder.
The roof is finished by applying a layer of waterproof elastomeric coating which covers the entire surface creating a monolithic structure.
The present invention can best be understand in connection with the accompanying drawings, in which:
The roofing system of this invention uses rigid foam boards or panels to create a seamless waterproof roof. It can be used over a number of different substrates including metal decking, tar and gravel, or polyurethane foam in new construction as well as re-roofing applications.
Rigid foam panels are currently available for use as insulating underlayment in roof construction. Typically these are 4′ by 8′ (1.22 m by 2.44 m) panels 1.5′″ (3.8 cm) thick made of a 1.6 pound per cubic foot polyurethane foam with a tar paper top layer. Such a material is not crush resistant enough to be used as a roof surface material and can also be easily punctured.
The roofing panels of this invention differ from this underlayment product in several respects. Although panel size as well as material are similar, the panels of this invention are made of a denser polyurethane foam (approximately 3 pounds per cubic foot) and include an integral top layer of non-woven 250 gram polyester fabric that is saturated by the foam during manufacture by the laminator in a controlled factory environment. The higher density affords more crush resistance, while the well bonded top layer resists punctures and provides a better adhesion surface for elastomeric top coats.
Since a protruding tongue of polyurethane foam could be damaged in transit, an alternate embodiment of a tongue-in groove construction is shown in
As shown in
Foam adhesive is a two-part mixture that has distinct phases after mixing. By varying the formulations of the two parts, the “cream time” (i.e.—to achieve the consistency of shaving cream) as well as the “tack free” time can be controlled. For this invention, a cream time of about 1 minute and a tack-free time of about 4 minutes is ideal. The panels are placed on the foam just after cream consistency and well before tack-free time so that the foam rises through the joints.
After the adhesive cures to a solid consistency, the blobs 18 are removed from all of the joints. This is typically accomplished by grinding using a cutter, such as a knife or disk pad grinder. At this stage, the joint is flush with the fabric top surface of the adjacent panels.
The roof is finished by applying a layer of waterproof elastomeric coating which covers the entire surface creating a monolithic structure.
Flow chart 7 is a concise description of the overall installation process. Two people are generally involved as a team. One worker sprays a panel-width line of low rise polyurethane adhesive, while the second worker follows (after the mix is of cream consistency) and lay down panels. As per
Penetrations and wall flashings are first sealed with spray foam prior to sealing.
For example,
The next layer shown in
The gypsum layer 140 shown in
It is further noted that other modifications may be made to the present invention, within the scope of the invention, as noted in the appended Claims.
This application is a continuation in part of application Ser. No. 10/601,046 filed Jun. 21, 2003 now U.S. Pat. No. 7,036,285, which is a continuation of application Ser. No. 10/022,612 filed Dec. 18, 2001 now U.S. Pat. No. 6,581,348, which claims benefit from provisional application Ser. No. 60/298,517 filed Jun. 15, 2001.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4739603 | Butler | Apr 1988 | A |
| 4745032 | Morrison | May 1988 | A |
| 4786543 | Ferm | Nov 1988 | A |
| 5037685 | Richards et al. | Aug 1991 | A |
| 6581348 | Hunter, Jr. | Jun 2003 | B2 |
| 20030089061 | DeFord et al. | May 2003 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20040200154 A1 | Oct 2004 | US |
| Number | Date | Country | |
|---|---|---|---|
| 60298517 | Jun 2001 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10022612 | Dec 2001 | US |
| Child | 10601046 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10601046 | Jun 2003 | US |
| Child | 10750397 | US |