US20040261347A1

US20040261347A1 - Base sheet for self-adhering membranes and selvage roll for such membranes

Info

Publication number: US20040261347A1
Application number: US10/864,225
Authority: US
Inventors: John Hageman
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-06-09
Filing date: 2004-06-09
Publication date: 2004-12-30

Abstract

A base sheet for a roof includes a laminate of a metal layer, a core layer and a plastic layer with the metal layer being on one side of the core layer and the plastic layer being on an opposite side. The core layer is made of a polyester non-woven fabric, a polypropylene non-woven fabric, a polyethylene non-woven fabric or a woven or non-woven fiberglass; the plastic is made of polyester, polypropylene, polyethylene or a spun bonded olefin; and the metal of the metal layer is aluminum. A self-adhering membrane is adhered to the laminate. Preferably, the self-adhering membrane includes a mineral surfaced area and a plurality of non-mineral surfaced areas forming selvage strips. The base sheet may be attached to an insulating board in situ or may be attached to the insulating board in a factory. In the latter case, the base sheet has at least two overhanging sides.

Description

CROSS REFERENCES TO RELATED APPLICATION

This application is based on Provisional Application Ser. No. 60/477,491, filed Jun. 9, 2003 and entitled “IMPROVED BASE SHEET,” Provisional Application Ser. No. 60/482,213, filed Jun. 24, 2003 and entitled “IMPROVED BASE SHEET” and Provisional Application Ser. No. 60/487,713, filed Jul. 16, 2003 and entitled “SELVAGE ROLL.” The entire disclosure of each of the provisional applications is incorporated by reference herein.[0001]

BACKGROUND OF THE INVENTION

The present invention relates generally to roofs and, more particularly, to a roof having an improved base sheet for self-adhering membranes and a selvage roll for such membranes.

Conventionally, roof membranes are applied to base sheets using a variety of methods.

One method of application is referred to as “torching,” in which the back surfaces of the rolls are heated. Heating of the bitumen-based roofing membranes is typically carried out by use of propane gas burners or torches. When the flame, which has a typical temperature of 1,000 to 1,300 degrees Celsius is directed toward the bottom surface of the sheet, APP compound from the bottom surface reaches a molten state and starts to flow onto the substrate and then cools to form a waterproofing bond. It is obvious that torching is dangerous considering the risk of fire caused by the utilization of a torch and other similar equipment.

Another method is applying hot asphalt to the base sheet by a technique known as “hot mopping.” Hot mopping, while reducing the risk of fire versus torch application, still poses a substantial risk of fire.

A further method, which essentially reduces the risk of fire to the base sheet and underlying structure is the use of self-adhering membranes. A self-adhering membrane is a membrane that can adhere to an underlying layer and to an overlying layer at overlaps without the use of an additional adhesive. The undersurface of a self-adhering membrane is protected by a release paper or film, which prevents the membrane from bonding to itself during shipping and handling.

Self-adhering membranes are usually formed into rolls for use in installing the membrane on a roof. Currently, self-adhering membranes have a top selvage edge and one selvage end lap. A selvage edge is an edge or edging that differs from the main part of (1) a fabric, or (2) granule-surfaced roll roofing material. More specifically, in the case of self-adhering modified bitumen membranes, the mineral surfacing is omitted over a small portion of the longitudinal edge of a sheet in order to obtain better adhesion of the lapped sheet surface with an overlying sheet. Ideally, the two sheets should be joined with the use of an adhesive selvage edge. Unfortunately, many times a roll must be cut short of the selvage end lap due to the dimensions of the roof. When this happens, the selvage end lap gets cut off and the material must now adhere to a mineral-surfaced edge. However, the material does not adhere well to such an edge.

SUMMARY OF THE INVENTION

The present invention provides a base sheet which may be used with either conventional methods of applying overlying layers or with self adhering membranes and, in either case, provides superior fire resistance.

The present invention also provides a selvage roll for self-adhering membranes, particularly self-adhering modified bitumen membranes, which solves the end lap problem.

In the case of a built-up roof, the metal layer serves as a fire barrier to prevent bitumen entering the underlying building and fueling a fire. Additionally, the metal layer acts as a barrier for preventing any bitumen (or other material) applied during installation from penetrating the deck and into the interior of the underlying building.

Whatever the type of roof assembly, the metal layer enables the roof assembly to resist an interior fire.

The provision of a plurality of selvage portions enables allows sizing of a roll to required dimensions while still providing a selvage end lap to enable the roll to be attached in a mineral free portion to an overlying roll.

Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a prior art roof; [0014]
FIG. 2 is a sectional view of a roof illustrating certain features of the present invention; [0015]
FIG. 3 is a sectional view of a roof having a self-adhering membrane illustrating certain features of the present invention; [0016]
FIGS. 4 and 5 are a perspective view and an elevation view, respectively, illustrating certain features of the present inventions, of a factory installed combined insulating board and base sheet wherein the base sheet overhangs the insulating board on at least two sides; [0017]
FIGS. 6 and 7 are a plan view and a perspective view, respectively, of a base sheet having selvages illustrating certain features of the present invention; and [0018]
FIG. 8 is a plan view of an alternative embodiment of a base sheet having selvages illustrating certain features of the present invention.[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Although the present invention is applicable to any type of roof, it has particular applicability in connection with its use in built-up, single ply and self-adhering membrane type roofs. [0020]
Built-up roofs are formed of alternate layers of bituminous material and felt which are assembled or “built-up” in the field. The alternate layers of bituminous material and felt are assembled onto an overlay which overlies an insulation layer. The insulation layer and overlay are attached to a roof deck which typically is made of metal, wood, concrete gypsum or any other conventional deck material. The term “built-up roof composite” as used herein means any one of a plurality of different conventional built-up roof composites used on the top of overlays, such as the built-up roof composite described herein, as well as others, such as EPDM, PVC, modified bitumen, coal tar and Hypolon. [0021]
An alternative structure to the built-up roof is a weather resistant elasto-plastic membrane which may comprise, for example reinforced polyvinyl floride, butyl rubber, vinylidene chlorides and fluorides, polyesters, polyvinyl chloride, neoprene, chlorosulfonated polyethylene, polysulfides, polyurethanes, polyepoxies, acrylates, and other materials having suitable mechanical strength and weather durability. Such structures are generally designated “single-ply roofs” because a single thickness of the weather-resistant membrane is generally sufficient, as compared with the plurality of layers of roofing felt generally required for built-up roofs. In addition to the membrane, a layer of insulating material is also generally provided between the membrane and the roof deck of the structure in single-ply roofs. [0022]
A self-adhering membrane type roof is formed from two or more membranes that can adhere to an underlying layer and to an overlying layer at overlaps without the use of an additional adhesive. The undersurface of a self-adhering membrane is protected by a release paper or film, which prevents the membrane from bonding to itself during shipping and handling. [0023]
The term “roof covering” as used herein means either a built-up roof composite, a single ply or a self-adhering membrane. [0024]
Referring now to the drawings and, particularly, to FIG. 1, there is shown an embodiment of a [0025] roof 20 illustrating certain features of the invention described in U.S. Pat. No. 6,108,993, the entire disclosure of which is incorporated by reference herein. The roof 20 includes a deck 21 which, as shown in FIG. 1, is made of metal but which may be made of wood, concrete, gypsum or any other conventional deck material. Overlying the deck 21 is an insulation layer 22 which typically is made of any conventional roof insulating material, such as isocyanurate, polyurethane, wood fiber, fiber glass, perlite or any other lightweight insulating material. A base sheet 23 comprising a laminate of metal 24 and fabric 26 overlies the insulation layer 22. Preferably, the metal 24 is aluminum and may be 2 mils thick and the fabric 26 is a non-woven polyester having a weight ranging from 4 to 14 ounces per square yard. A polyester sheet having satisfactory properties is one made by the Hoechst Celanese Company, New Jersey and sold under the trade name of Trivera®.
The [0026] base sheet 23 and the insulating layer 22 are attached to the deck 21 by suitable mechanical fasteners 27, such as screws or nails, which are inserted through respective metal plates (not shown). Over the base sheet 23 a conventional roof covering 28 which may be either a built-up roof composite or a single ply membrane is formed.
In accordance, with the present invention, referring to FIG. 2, there is shown a [0027] roof 30 in which the base sheet 23 of FIG. 1 is replaced with a base sheet 32. The base sheet 32 has a plastic film 34 laminated to one side of a core layer 36 and a metal foil 38 laminated to the opposite side.
The [0028] plastic film 34 may be composed of any plastic, such as polyester, polypropylene, polyethylene or a spun bonded olefin, such as Tyvek spun bonded olefin.
The [0029] core layer 36 may be composed of any non-woven fabric, such as polyester non-woven fabric polypropylene non-woven fabric, polyethylene non-woven fabric or a woven or non-woven fiberglass.
The [0030] metal foil 38 may be made from any metal, but preferably is made of aluminum.
The base sheet may be used with either the plastic side, as shown in FIG. 2, up or the [0031] metal side 38 up. In either case, a self-adhering membrane adheres to the base sheet in a superior manner.
Typically, as discussed above, built-up roof composites are formed of alternate layers of bituminous material and felt. The felts may be fiberglass or may be organic felt, such as asphalt saturated felt or, as disclosed in U.S. Pat. Nos. 4,521,478, 4,599,258 and 4,837,095, the entire disclosures of which are incorporated by reference, the built-up [0032] roof composite 27 may be formed of alternate layers of a non-woven polyester and bituminous material. Typically, the bituminous material is usually of coal tar or asphalt origin and is applied by hot-mopping. The metal layer 24 acts as a barrier to prevent the bituminous material from penetrating down to the underlying insulation layer 22.
One of the problems with built-up roofs employing bituminous materials is that when there is an internal fire in the building, the temperatures can be such as to cause the bituminous material to liquify and penetrate through the deck into the interior, thereby feeding the fire and causing greater fire damage, as well as greater hazard to fire personnel involved in fighting the fire. Accordingly, it is necessary to provide a barrier to such bituminous liquid from entering the building. The metal foil provides such a barrier. Further, the fire resistance of the metal foil also allows the self-adhering roof membrane to pass a calorimeter fire test. This test measures a roof assembly's capabilities to resist an interior building fire. [0033]
The [0034] laminate base sheet 32 of the present invention is generally applied in discontinuous units such that seams are formed which normally would allow molten material to flow into the interior of a building. However, it has been found that the seams at the high temperatures encountered in a building fire cause melting of the overlying polyester, which then enters the seam forming a fluid type seal between adjacent metal layers 38. This seal prevents any liquid bituminous material from passing through to any of the underlying layers.
When the roof covering [0035] 28 is a single ply membrane, such membrane preferably comprises an elasto/polymeric material. Without limitation on the generality of useful materials, the membrane may be formed of ethylene propylene diene monomer (EPDM), modified bitumen (MB), reinforced modified bitumen (MB/R), polychloroprene or neoprene (NEO), polyvinyl chloride (PVC), chlorinated polyethylene (CPE), polyisobutylene (PIB), or ethylene-copolymer-bitumen and anthracite microdust (ECB). The adhesive is chosen for its compatibility with the material comprising the membrane.
When the roof covering [0036] 28 is formed from self-adhering membranes, such as the self-adhering membranes 40 and 42 (FIG. 3), any self-adhering membrane may be used such as, self-adhering modified bitumen, SBS modified bitumen, APP modified bitumen, etc.
To install the [0037] roof 30, the insulation layer 22 is first laid over the deck 21. Typically the insulation layer 22 is laid over the deck as a plurality of individual boards. Then, the base sheet 32, which typically is supplied from rolls approximately 40″ in width, is laid on the roof in strips of 40″ width with overlapping seams. The base sheet 32 and the insulation layer 22 are then attached to the deck by a plurality of mechanical fasteners 27 which may be screws, nails or, depending upon the deck, toggle bolts, or any other conventional mechanical fastener, and which are typically inserted through respective metal plates (not shown).
As an alternative to applying the base sheet in situ on the insulating layer in discontinuous units, the base sheet may be attached to the insulating layer in a factory. In this case, as shown in FIGS. 4 and 5, a [0038] base sheet 41 is laminated to a roofing insulation board 43 of any size. The base sheet 41 is laminated to the insulation board such as to have at least two sides 41 a and 41 b overhang the board with the other sides cut even to the insulating board. Thus, when the boards 43 are applied to a roof deck, the base sheet 41 will lap over the preceding side. The advantages are:
1. The [0039] base sheet 41 prevents gassing of the insulating board 43 when using urethane, isocyanurate or any foam that utilizes gas in the cell. It is well known in the industry that isocyanurate insulation releases gas from the topside when hot coal tar or hot asphalt is applied. This gassing causes blistering and delamination of the roofing membrane. Thus, in installation, the base sheet 41 eliminates the cost of the labor and cost of the board overlay which is recommended by NRCA.
2. The installing of the [0040] base sheet 41 over the insulation boards 43 prevents hot molten tar or asphalt flowing between the joints of the insulation board 43, thereby protecting occupants from serious burns. In the case of new construction, it prevents inside workers from being burned by dripping hot tar or asphalt.
3. The [0041] base sheet 41, because of the tear resistance of spun bond plastic, enables the insulation board 43 to be secured to the deck utilizing 50% less fasteners then insulating boards void of the base sheet 41. For example, if insulation boards void of the base sheet 41 were installed, approximately 36 fasteners would be utilized per 100 sq. ft. to obtain a 90 PSI rating. This wind lift rating is required to be in compliance with all building codes in the United States. This reduction in fasteners means less holes in the deck, 50% less fasteners plus 50% less labor for the installation.
4. [0042] Insulation boards 43 for roofing tend to be brittle. The lamination of the base sheet 41 to the board 43 reduces the breakage during shipping and installation resulting in lower costs.
5. The [0043] base sheet 41 adds dimensional strength to the insulation board 43. It is well known in the industry that roofing insulation, especially foam type insulation lacks dimensional stability.
6. When attaching fasteners through insulation, it is necessary that all fasteners are installed at the top of metal decking, i.e., in order to pass Factory Mutual or Global or UL uplift regulations and to comply with test listings, all fasteners must be at the top of metal decking. When using a roll consisting of the base sheet, it is very difficult to locate the top of a corrugated steel decking. Using the composite base sheet/insulating board eliminates this problem. [0044]
7. When the [0045] base sheet 41 is laminated to the insulation 43 at the factory, the task of installation is made easier as the individual boards are laid individually and fastened. In contrast, in the loose laid method, the wind is a negative factor, blowing unfastened insulation and causing work stoppage and damage to insulation boards.
8. The aluminum of the [0046] base sheet 41 acts as a vapor retarder, preventing interior moisture in the form of vapor, from entering under and into the roof membrane which can cause blistering.
9. The overlapping of the joints of [0047] adjacent boards 43 by the overhangs 41 a and 41 b, prevents asphalt from flowing through the joints and into the building feeding the fire from within.
10. The two sides that overlap cover the seams in the insulation saving time and labor by not having to tape the seams in the insulation. [0048]
The [0049] base sheet 41 may be the base sheet 32 described above or it may be the composite polyester/aluminum base sheet described in U.S. Pat. No. 5,884,446 and U.S. Pat. No. 6,108,993, the entire disclosures of which are incorporated herein by reference. In either case, the base sheet may be attached to the insulation board 43 with the aluminum side up or down.
After application of the insulation layer and the base sheet, the roof covering [0050] 28 is applied. In the case where the roof covering 28 is a built-up roof composite, the built-up roof composite is formed by hot-mopping alternating layers of a hot bituminous material, such as hot asphalt, onto the base sheet 32 with intervening layers of a felt which may be a non-woven polyester or any other conventional felt material.
In the case where the roof covering [0051] 28 is a single ply membrane, the single ply membrane is applied to the base sheet 32 by a suitable adhesive. In the case where the roof cover is formed from self-adhering membranes 40 and 42 (FIG. 3) the self-adhering membrane 40 is attached to the base sheet using the adhesive backing of the self-adhering membrane 40. Thereafter one or more additional membranes 42 are applied with the adhesive backing of an overlying membrane enabling that membrane to be attached to the membrane below it.
Preferably, each roll [0052] 44 of self-adhering membrane (40, 42) is formed as shown in FIGS. 6 and 7, such as to include a mineral surfaced area 46 on a substrate 48 having a plurality of selvage strips 50 formed along the roll. The width of each selvage strip may be 4 to 8 inches and they may be two or three feet apart. It should be recognized that these dimensions are only exemplary, and the width of the selvage strips 50 and their spacing may have any dimensions suitable for the roll's use. Further, the selvage strips 50 may be formed transversely, as shown in FIGS. 6 and 7, or selvage strips 52 may be formed longitudinally, as shown in FIG. 8.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims. [0053]

Claims

What is claimed is:

1. A base sheet for a roof comprising a laminate of a metal layer, a core layer and a plastic layer with the metal layer being on one side of the core layer and the plastic layer being on an opposite side.

2. The base sheet of claim 1, wherein the core layer is made of a polyester non-woven fabric, a polypropylene non-woven fabric, a polyethylene non-woven fabric or a woven or non-woven fiberglass.

3. The base sheet of claim 1, wherein the core layer is made of a fabric.

4. The base sheet of claim 3, wherein the fabric is a polyester non-woven fabric, a polypropylene non-woven fabric, or polyethylene non-woven fabric.

5. The base sheet of claim 1, wherein said plastic is made of polyester, polypropylene, polyethylene or a spun bonded olefin.

6. The base sheet of claim 1, wherein the metal of said metal layer is aluminum.

7. The base sheet of claim 1, wherein the metal of said metal layer is aluminum, the core layer is made of non-woven polyester and the plastic is a polyester.

8. A roll of roofing material comprising a self-adhering membrane having a mineral surfaced area and a plurality of non-mineral surfaced areas forming selvage strips.

9. The roll of roofing material according to claim 8, wherein the self-adhering membrane comprises a self-adhering modified bitumen, a SBS modified bitumen, or an APP modified bitumen.

10. The roll of roofing material according to claim 8, wherein the selvage strips are formed transversely along the membrane.

11. The roll of roofing material according to claim 8, wherein the selvage strips are formed longitudinally along the membrane.

12. A roof comprising:

a deck; and

a laminate of a metal layer, a fabric layer and a plastic layer overlying said deck with the metal layer being on one side of the fabric layer and the plastic layer being on an opposite side attached to the deck; and

a roof covering over the laminate.

13. The roof of claim 12, wherein the core layer is made of a polyester non-woven fabric, a polypropylene non-woven fabric, a polyethylene non-woven fabric or a woven or non-woven fiberglass.

14. The roof of claim 12, wherein said plastic is made of polyester, polypropylene, polyethylene or a spun bonded olefin.

15. The roof of claim 12, wherein the metal of said metal layer is aluminum.

16. The roof of claim 12, wherein the core layer is made of a fabric.

17. The roof of claim 16, wherein the fabric is a polyester non-woven fabric, a polypropylene non-woven fabric, or a polyethylene non-woven fabric.

18. The roof of claim 12, wherein the metal of said metal layer is aluminum, the core layer is made of non-woven polyester and the plastic is a polyester.

19. The roof of claim 18, wherein the roof covering is a built-up roof composite.

20. The roof of claim 18, wherein the roof covering is a single-ply membrane.

21. The roof of any one of claims 12-18, wherein the roof covering is a self-adhering membrane.

22. The roof of claim 21, wherein the self-adhering membrane comprises a mineral surfaced area and a plurality of non-mineral surfaced areas forming selvage strips.

23. The roof of claim 22, wherein the membrane comprises a modified bitumen, a SBS modified bitumen, or an APP modified bitumen.

24. The roof of claim 23, wherein the selvage strips are formed transversely along the membrane.

25. The roof of claim 23, wherein the selvage strips are formed longitudinally along the membrane.

26. A method of forming a roof on a deck comprising:

placing an insulating layer over said deck;

placing a laminate of a metal layer, a core layer and a plastic layer with the metal layer being on one side of the core layer and the plastic layer being on an opposite side on the insulating layer; and

adhering a self-adhering membrane to the laminate.

27. The method of claim 26, wherein the laminate is placed on the roof deck such that the metal layer faces the deck and wherein the self-adhering membrane is adhered to the plastic layer.

28. The method of claim 26, wherein the laminate is placed on the roof deck such that the plastic layer faces the deck and wherein the self-adhering membrane is adhered to the metal layer.

29. The method of claims 27 or 28, wherein the core layer is made of a polyester non-woven fabric, a polypropylene non-woven fabric, a polyethylene non-woven fabric or a woven or non-woven fiberglass.

30. The method of claim 29, wherein said plastic is made of polyester, polypropylene, polyethylene or a spun bonded olefin.

31. The method of claim 29, wherein the metal of said metal layer is aluminum.

32. The method of claim 29, wherein the core layer is made of a fabric.

33. The method of claim 32, wherein the fabric is a polyester non-woven fabric, a polypropylene non-woven fabric, or a polyethylene non-woven fabric.

34. The method of claim 29, wherein the metal of said metal layer is aluminum, the core layer is made of non-woven polyester and the plastic is a polyester.

35. The method of claim 34, wherein the self-adhering membrane comprises a mineral surfaced area and a plurality of non-mineral surfaced areas forming selvage strips.

36. The method of claim 35, wherein the membrane comprises a modified bitumen, a SBS modified bitumen, or an APP modified bitumen.

37. The method of claim 36, wherein the selvage strips are formed transversely along the membrane.

38. The method of claim 36, wherein the selvage strips are formed longitudinally along the

39. The method of claims 27 or 28, wherein the self-adhering membrane comprises a mineral surfaced area and a plurality of non-mineral surfaced areas forming selvage strips.

40. The method of claim 39, wherein the membrane comprises a modified bitumen, a SBS modified bitumen, or an APP modified bitumen.

41. The method of claim 40, wherein the selvage strips are formed transversely along the membrane.

42. The method of claim 41, wherein the selvage strips are formed longitudinally along the membrane.

43. A combined base sheet and insulating layer for a roof, comprising: a laminate including a metal layer, and at least one plastic layer attached to an insulating board such that at least two sides of the laminate overhang two sides of the insulating board.

44. The base sheet of claim 43, wherein said at least one platic layer is made of a spun bonded plastic.

45. The base sheet of claim 43, wherein said at least one plastic layer is made of polyester, polypropylene, polyethylene or a spun bonded olefin.

46. The base sheet of claim 1, wherein the metal of said metal layer is aluminum.

47. A method of forming a roof on a root deck comprising:

providing a plurality of insulating boards having respective laminates of a metal layer and at least one plastic layer attached to the boards, each laminate having at least two overhanging sides; and

placing the plurality of insulating board on the roof deck such that each overhang of a laminate overlaps a side of another insulating board.

48. The method of claim 47, further comprising adhering a self-adhering membrane to the laminate.

49. The method of claim 48, wherein the laminate is placed on the insulating board such that the metal layer faces the insulating board and wherein the self-adhering membrane is adhered to the plastic layer.

50. The method of claim 48, wherein the laminate is placed on the insulating board such that the plastic layer faces the insulating board and wherein the self-adhering membrane is adhered to the metal layer.