Insulation board with improved performance

Abstract

A roof assembly, having: a roof deck; an insulation board assembly mounted onto the roof deck; and a roofing membrane adhered onto the insulation board assembly, wherein the insulation board assembly comprises: a foam insulation board, a woven top facer on a top side of the foam insulation board, and a woven bottom facer on a bottom side of the foam insulation board.

Claims

1. A roof assembly, comprising: a roof deck; an insulation board assembly mounted onto the roof deck; and a roofing membrane adhered onto the insulation board assembly, wherein the insulation board assembly comprises: a foam insulation board having first and second opposing surfaces, a woven top single layer facer on a top side of the foam insulation board, wherein the woven top facer is in direct contact with the first surface of the foam insulation board, and the woven top facer defines an outermost top surface of the insulation board assembly, and wherein the top single layer facer has a warp density from 4 to 30 ends per inch or a weft density from 4 to 30 picks per inch and wherein the top single layer facer has a tensile strength greater than 80 lbf/3 inch in both a machine direction and a cross direction, and a tear strength of over 15 lbf in both the machine direction and the cross direction, and a woven bottom single layer facer on a bottom side of the foam insulation board, wherein the woven bottom facer is in direct contact with the second surface of the foam insulation board, and the woven bottom facer defines an outermost bottom surface of the insulation board assembly, and wherein the bottom single layer facer has a warp density from 4 to 30 ends per inch or a weft density from 4 to 30 picks per inch and wherein the bottom single layer facer has a tensile strength greater than 80 lbf/3 inch in both a machine direction and a cross direction, and a tear strength of over 15 lbf in both the machine direction and the cross direction, and wherein the top and bottom facers comprise no glass fibers.

2. The roof assembly of claim 1, wherein the roof assembly meets the Very Severe Hail rating of FM 4470 (Class 1).

3. The roof assembly of claim 1, wherein the roof deck is made of steel, wood or concrete.

4. The roof assembly of claim 1, wherein the insulation board is made of polyisocyanurate or polyurethane.

5. The roof assembly of claim 1, wherein the roofing membrane is made of thermoplastic olefin, ethylene propylene diene monomer or polyvinyl chloride.

6. The roof assembly of claim 1, wherein the roofing membrane is fleece-backed.

7. The roof assembly of claim 1, wherein the top and bottom facers are woven from yarns or tapes made from synthetic polymers.

8. The roof assembly of claim 1, wherein the top and bottom facers comprise woven polypropylene material and/or propylene alpha-olefin copolymers or ethylene alpha-olefin copolymers.

9. The roof assembly of claim 1, wherein the insulation board assembly exhibits a fastener Pull-Through value that is higher than 300 lbf.

10. The roof assembly of claim 1, wherein the foam insulation board has a density of 0.5 to 6.0 pcf.

11. The roof assembly of claim 1, wherein the top and bottom facers comprise yarns or tapes.

12. The roof assembly of claim 1, wherein the top and bottom facers have a weight from 40 to 200 grams per square meter.

13. The roof assembly of claim 1, wherein the top and bottom facers each have a thickness from 2 mil to 50 mil.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a sectional side elevation view of a foam insulation board with top and bottom woven facers.

(2) FIG. 2 is a sectional side elevation view of a foam insulation board similar to FIG. 1, but with a non-woven layer or coating above and below each of the top and bottom woven facers.

(3) FIG. 3 is a sectional side elevation view of a foam insulation board similar to FIG. 2, but with a tie layer securing the woven and non-woven layers together.

(4) FIGS. 4A to 5B illustrate various embodiments of roofing assemblies in which the present insulation board assembly is incorporated, showing many different possible uses for the present insulation board assembly, as follows.

(5) FIG. 4A is a perspective view of the present insulation board assembly secured to a corrugated roof, with a protective coverboard thereover and a fleece backed membrane adhered over the top of the coverboard.

(6) FIG. 4B is a view similar to FIG. 4A, but with a non-fleece membrane instead adhered over the top of the coverboard.

(7) FIG. 5A is a perspective view of the present insulation board assembly secured to a corrugated roof, similar to FIG. 4A, but with the protective coverboard removed.

(8) FIG. 5B is a view similar to FIG. 5A, but with a non-fleece membrane instead adhered directly onto the top of the present insulation board assembly.

DETAILED DESCRIPTION OF THE PRESENT SYSTEM

(9) As stated above, in one embodiment as seen in FIG. 1, the present system provides an insulation board assembly 10 that comprises: a foam insulation board 12 that may optionally be made of polyurethane or polyisocyanurate foam, or a phenolic material or an expanded polystyrene material (EPS)); a top woven facer 20A attached onto a top side of the foam insulation board, top facer 20A being made of woven material that may optionally include polypropylene; and a woven bottom facer 20B attached onto a bottom side of the foam insulation board, bottom facer 20B also optionally being made of woven polypropylene. In alternate aspects, other woven materials may be used instead, including both natural and synthetic fibers.

(10) In another embodiment, the present system provides a thin, rolled woven facer material that has sufficient strength in both its machine and cross directions that can be attached onto the foam insulation board (for example, during an extrusion process with the foam being sandwiched between top and bottom woven facers).

(11) Traditionally, polyurethane or polyisocyanurate is a closed-cell, rigid foam insulation board consisting of a foam core sandwiched between two facers. It is the most widely used insulating material for above-deck commercial roof construction in North America. In many existing systems, the facer materials are fiberglass, but even kraft paper has been used. These polyurethane or polyisocyanurate insulation boards are attached to the roof deck with various mechanical fasteners and construction adhesives or held in place with ballast stones or concrete pavers placed above the roofing membrane. Typically, the roofing membrane also may be mechanically attached through the foam insulation, adhered to the top polyurethane or polyisocyanurate facer or even held in place with ballast.

(12) In accordance with the present system, the present inventors experimentally tested various facers (GRF, CGF, Non-woven polyester and woven polypropylene facer materials). The results of these experimental tests are shown in Table 1, below:

(13) TABLE-US-00001 TABLE 1 Common physical properties of different facer materials. GRF CGF Nonwoven PET Woven PP Tensile (MD) 46 69 107 132 (lbf/3 in.) Tensile (CD) 38 67 67 119 (lbf/3 in.) Breaking 1.7 2 39 14 Elongation-MD (%) Breaking 2 2 50 12 Elongation-CD (%) Tear MD (lbf) 0.4 0.6 6.8 47.0 Tear CD (lbf) 0.7 0.8 10.5 49.0

(14) In addition, the present inventors also experimentally tested the same facer materials for “Pull-Through” and “wind uplift”. The results of these experimental tests are shown in Table 2 below.

(15) The Pull-Through test procedure is designed to evaluate the strength of substrate/stress plate combinations by using tensile loading. The test method described below utilizes a nominal 14×14 in. test sample and test jig. The test method is intended to be used to evaluate various membranes, membrane/stress plate combinations, substrates or substrate/stress plate combinations for comparison to each other in order to determine the products are to be used large scale wind resistance classification testing.

(16) The detailed testing procedure is as follows. The 14×14 Substrate Test Jig is secured to the moving crosshead of the Tinius Olsen machine. When ready for testing, the sample is slid into the 14×14 Substrate Test Jig with the stress plate located on the underside of the test sample. The screw end of the fastener is then secured in into the stationary jaw. Zero the Tinius Olsen machine to clear data before the first sample is tested. Force is exerted in a direct line perpendicular to the plane of the substrate/stress plate interface at a crosshead speed of 2 in./min (51 mm/min). While the sample is being tested, the sample shall be visually examined to ensure that it continues to meet the Conditions of Acceptance. Continue the testing until the sample fails, higher forces are unable to be attained or maintained, or at the discretion of the test sponsor. Failure is considered to occur when the Conditions of Acceptance are no longer being met or until the tensile force is no longer able to be maintained. Upon completion of the test, the sample shall be examined and any item not conforming to the Conditions of Acceptance noted. The results of the Pull-Through Test shall be stated in pounds. The result assigned to the sample shall be the maximum force which the sample reached prior to failure. Conditions of Acceptance are: 1. all samples should remain secured in their test jig until failure of the test sample; 2. the overall sample results shall be determined based on the average of three (3) tests. If the standard deviation of the three values divided by the mean is greater than 20%, an additional test(s) shall be conducted. The results of all tests shall be used to determine the final average.

(17) TABLE-US-00002 TABLE 2 Performance of polyisocyanurate board with different facer materials. Facer Type GRF CGF Nonwoven PET Woven PP Pull-through (lbf) 177 262 263 455 Wind uplift 1-60 1-90 1-105 1-120

(18) While the woven facer performed exceedingly well when compared to GRF and CGF with fastener pull-through/wind uplift, it also shows superior performance with regard to moisture resistance per ASTM C209-Water Absorption. This is shown below in Table 3.

(19) TABLE-US-00003 TABLE 3 Moisture absorption of polyisocyanurate board with different facer materials. Facer Type GRF CGF Non woven PET Woven PP Water Absorption 0.39% 0.30% 0.07% 0.06%

(20) As a result of this testing, it was discovered that woven polypropylene facers 20A and 20B offered substantial benefits (as described herein) over traditional GRF and CGF facers.

(21) In particular, the present woven facers 20A and 20B provide the advantages of strength in both (perpendicular) machine direction and cross directions. In preferred aspects, the strength in the cross direction is at least 70% of the strength in the machine direction.

(22) In the case of woven facer materials supplied on rolls, the present facer materials preferably have weight of 20 gsm to 200 gsm; and a tensile strength of at least 80 lb. The advantage of this small thickness is that it makes the facers easier to roll.

(23) In various optional aspects, the woven facers 20A and 20B can be made of natural and/or synthetic yarns and/or tapes. The synthetic yarns or tapes can be made from polymers such as polyethylene, ethylene and alpha-olefin copolymers, polypropylene, propylene and alpha-olefin copolymers, nylon, polyester, acrylic polyester, polyamide, aramid etc. The yarns can be made from natural fibers, such as cotton, cellulose, wool, rayon, silk, hemp, sisal, etc.

(24) In preferred embodiments, the present insulation board assembly meets the Very Severe Hail (VSH) rating of FM 4470 (Class 1). This can even be accomplished using low or typical density insulation board. In one embodiment, the foam insulation board has a density of 0.5 to 6.0 pcf. This represent an advantage over existing (and costlier) approaches of using gypsum or press board to achieve the Very Severe Hail (VSH) rating.

(25) In addition, the adhesion between the insulation board and the facer could potentially be stronger than can be achieved by existing standard density insulation boards and facers made of paper, glass fiber reinforced paper or coated glass facers (GRF/CGF), foils, films or laminates.

(26) In optional preferred embodiments, the present insulation board with woven facer may also be used under a sheet of roof membrane, such as EPDM (Ethylene Propylene Diene Monomer), TPO (thermoplastic olefin), PVC (polyvinyl chloride), KEE (ketone ethylene ester) or Hypalon, of various thickness to provide a roofing structure capable of achieving the Very Severe Hail (VSH) rating. Optionally, EPDM, TPO, PVC, KEE and Hypalon roof membrane can have non-woven materials laminated on the back side. The non-woven fleece could potentially improve the adhesion performance of roof membrane to the insulation board.

(27) In other optional preferred aspects, bonding adhesives are used to adhere the roof membrane onto the insulation board. Optionally, such bonding adhesive can include extruded coatings, spray coatings or roller applied coatings. Examples of such adhesive promoters include Flexible FAST™, TPO bonding adhesive, Cav-Grip III™ and EPDM bonding adhesive.

(28) Roof System Performance

(29) Factory Mutual's 4470's procedure for Very Severe Hail (VSH) Testing is a new test standard that has had a significant impact on the construction of commercial roof systems in fourteen states throughout the Midwest. The test involved propelling a 2-inch-diameter ice ball at a roof system test specimen at a velocity of 152 to 160 feet per second. The membrane must not be punctured and it must remain adhered to the substrate board. The substrate boards cannot be cracked or have the facers delaminated from the foam to pass this test.

(30) Two widely used cover boards (i.e.: High Density (HD) Polyiso and Gypsum board), that are used in the commercial roofing industry have been unable to withstand this VSH test (See Table 4 and 5 below). The only roofing systems that have been able to achieve limited success on the VSH rating so far have incorporated OSB cover boards and Plywood cover boards (See Table 6 below). However, the OSB and Plywood boards have significant limitation since they are expensive, heavier than 0.5″ HD Polyiso, and are not able to achieve the same fire ratings that systems containing Gypsum or HD Polyiso cover boards.

(31) TABLE-US-00004 TABLE 4 VSH test results for ½″ SecurShield HD Polyiso board. Deck Reason Construction Testing VSH for Insulation Membrane Adhesive Type Location Results failure ½″ 145 EPDM Fleece Flex FAST FIG. 4A FM Fail Cracks SecurShield 115 EPDM Fleece Flex FAST FIG. 4A FM Fail in HD High Density 90 mil EPDM EPDM Bonding FIG. 4B FM Fail Board Polyiso Board 75 mil Sure- EPDM Bonding FIG. 4B FM Fail Tough 145 White EPDM Flex FAST FIG. 4A FM Fail Fleece 115 White EPDM Flex FAST FIG. 4A FM Fail Fleece 90 mil White EPDM Bonding FIG. 4B FM Fail EPDM 135 PVC Fleece Flex FAST FIG. 4A FM Fail 115 PVC Fleece Flex FAST FIG. 4A FM Fail 80 mil PVC PVC Bonding FIG. 4B FM Fail 135 TPO Fleece Flex FAST FIG. 4A FM Fail 115 TPO Fleece Flex FAST FIG. 4A FM Fail 80 mil TPO TPO Bonding FIG. 4B FM Fail

(32) TABLE-US-00005 TABLE 5 VSH test results for ½″ DensDeck Prime board (Gypsum). Deck Reason Construction Testing VSH for Insulation Membrane Adhesive Type Location Results failure ½″ 145 EPDM Fleece Flex FAST FIG. 4A FM Fail Loss of DensDeck 115 EPDM Fleece Flex FAST FIG. 4A FM Fail Adhesion Prime Board 90 mil EPDM EPDM Bonding FIG. 4B FM Fail (gypsum 75 mil Sure- EPDM Bonding FIG. 4B FM Fail turned to Tough powder 145 White EPDM Flex FAST FIG. 4A FM Fail at area of Fleece impact) 115 White EPDM Flex FAST FIG. 4A FM Fail Fleece 90 mil White EPDM Bonding FIG. 4B FM Fail EPDM 135 PVC Fleece Flex FAST FIG. 4A FM Fail 115 PVC Fleece Flex FAST FIG. 4A FM Fail 80 mil PVC PVC Bonding FIG. 4B FM Fail 135 TPO Fleece Flex FAST FIG. 4A FM Fail 115 TPO Fleece Flex FAST FIG. 4A FM Fail 80 mil TPO TPO Bonding FIG. 4B FM Fail

(33) TABLE-US-00006 TABLE 6 VSH test results for StormBase (OSB) board. Deck Reason Construction Testing VSH for Insulation Membrane Adhesive Type Location Results failure StormBase 145 EPDM Fleece Flex FAST FIG. 4A FM Fail cracks (OSB) 115 EPDM Fleece Flex FAST FIG. 4A FM Fail in 90 mil EPDM EPDM Bonding FIG. 4B FM Fail OSB 90 mil White EPDM Bonding FIG. 4B FM Fail EPDM 75 mil Sure- EPDM Bonding FIG. 4B FM Fail Tough 115 White EPDM Flex FAST FIG. 4A FM Fail Fleece 145 White EPDM Flex FAST FIG. 4A FM Pass Fleece 135 PVC Fleece Flex FAST FIG. 4A FM Fail heat 115 PVC Fleece Flex FAST FIG. 4B FM Fail aging 80 mil PVC PVC Bonding FIG. 4A FM Fail fail 135 TPO Fleece Flex FAST FIG. 4A FM Pass 115 TPO Fleece Flex FAST FIG. 4B FM Pass 80 mil TPO TPO Bonding FM Pass

(34) In contrast to the above existing systems, various embodiments of the present invention (i.e.: systems containing high density and normal density Polyiso insulation boards made with woven polypropylene facer materials) showed significant improvement and were able to withstand the VSH Test. The present roof systems successfully passed both internal and Factory Mutual tests due to the unique physical properties provided by the present woven facers. The results are summarized in the Table 7 and 8 below.

(35) As can be appreciated, the present roof systems using standard density or high density insulation board and woven PP facers can be paired with TPO FleeceBACK, EPDM FleeceBACK, PVC FleeceBACK, KEE FleeceBACK and bareback TPO, EPDM, PVC and KEE HP. These membranes may optionally be bonded with two-part polyurethane adhesive, TPO Bonding adhesives, PVC adhesives, EPDM Bonding Adhesives, water based adhesives, LVOC bonding adhesives and Cav-Grip III. This type of roof system has significant performance advantageous over that with OSB and plywood board as the insulation board with woven PP facer delivers higher R-value per inch and is less costly.

(36) TABLE-US-00007 TABLE 7 VSH test results for ½″ HD Polyiso board with woven PP facer. Deck Construction Testing VSH Insulation Source Membrane Adhesive Type Location Results ½″ HD This 45 mil TPO Cav-Grip III FIG. 4B in-house pass Polyiso w/ invention 60 mil TPO Cav-Grip III FIG. 4B in-house pass Woven PP 90 mil White 90-8-30A FIG. 4B in-house pass Facer EPDM 105 EPDM Fleece Flex FAST FIG. 4A in-house pass 60 mil TPO Cav-Grip III FIG. 4B FM pass 80 mil TPO Cav-Grip III FIG. 4B FM pass

(37) TABLE-US-00008 TABLE 8 VSH test results for normal density Polyiso board with woven PP facer. Deck Construction Testing VSH Insulation Source Membrane Adhesive Type Location Results Standard This 80 mil TPO Cav-Grip III FIG. 5B in-house pass Density invention 90 mil White 90-8-30A FIG. 5B in-house pass Polyiso w/ EPDM Woven PP 105 EPDM Fleece Flex FAST FIG. 5A in-house pass Facer 60 mil TPO Cav-Grip III FIG. 5B FM pass 80 mil TPO Cav-Grip III FIG. 5B FM pass

(38) In preferred aspects illustrated in FIG. 2, the woven facers preferably include chemical coatings to make them waterproof. Specifically, system 10 comprises a foam insulation board 12, having a top woven facer 20A and a bottom woven facer 20B, as described above. Preferably, top woven facer 20A and bottom woven facer 20B comprise no glass fibers. Foam insulation board preferably has a density of 0.5 to 6.0 pcf and the fastener Pull-Through value is higher than 300 lbf. Preferably, the roof assembly 10 consists of roof membrane, bonding adhesive and the insulation board, and wherein the roof assembly meets the Very Severe Hail rating of FM 4470 (Class 1).

(39) Preferably, each of woven facers 20A and 20B comprise yarns or tapes made from synthetic polymers such as woven polypropylene and/or propylene alpha-olefin copolymers or ethylene alpha-olefin copolymers having a warp density from 4 to 30 EPI or a weft density from 4 to 30 PPI, a weight from 40 to 200 grams per square meter, and a thickness of 2 mil to 50 mil. Preferably, each of the top and bottom facers 20A and 20B have a tensile strength greater than 80 lbf/3 inch in both a machine direction and a cross direction and a tear strength of over 15 lbf in both a machine direction and a cross direction.

(40) As seen in FIG. 2, each of facers 20A and 20B may optionally have a polymer coating on one or both side of one or both of the top and bottom facers (i.e.: 22A, 24A, 22B and 24B). In preferred aspects, some or all of polymer coating layers 22A, 24A, 22B and 24B are selected from the group consisting of: polyethylene, ethylene and alpha-olefin copolymers, polypropylene, propylene and alpha-olefin copolymers, silicones, acrylates, polyurethane, natural rubber, and styrene butadiene rubber.

(41) Alternatively, each of facers 20A and 20B may optionally have a non-woven material laminated on one or both side of one or both of the top and bottom facers (i.e.: layers 22A, 24A, 22B and 24B). The non-woven material layers may be selected from the group consisting of polyester, polyethylene, ethylene and alpha-olefin copolymers, polypropylene, propylene and alpha-olefin copolymers, nylon, glass, Kevlar, basalt, and carbon fiber. As such, layers 22A, 24A, 22B and 24B can comprise various polymer coatings or other non-woven material. Optionally, layers 24A and 24B can comprise a laminated glass mat, a glass scrim or a coated glass scrim.

(42) As seen in FIG. 3, the non-woven layers 24A and 24B can be laminated to the woven layers 20A and 20B via an adhesive or a tie layer 26A, 26B.

(43) In alternate aspects, the present system comprises a rolled insulation facer formed from a woven material having a tensile strength greater than 80 lbf/3 inch in both a machine direction and a cross direction, and a tear strength of over 15 lbf in both the machine direction and the cross direction. In this aspect, the woven material comprises yarns or tapes made from synthetic polymers, including but not limited to polypropylene and/or propylene alpha-olefin copolymers and/or ethylene alpha-olefin copolymers. Preferably, the woven material is waterproof.

(44) FIGS. 4A to 5B show four different roof assemblies into which the present insulation board assembly can be incorporated. The assemblies in each of FIGS. 4A to 5B are the assemblies that were specifically tested in each of Tables 7 and 8. As seen in particular in each of Tables 7 and 8, the present insulation board assembly (i.e.: an insulation board with top and bottom woven facers having properties as described herein), provides a system in which meets the Very Severe Hail rating of FM 4470 (Class 1).

(45) Accordingly, it is to be understood that the present insulation board assembly will pass the Very Severe Hail rating of FM 4470 (Class 1) when used in any of the four configurations of FIGS. 4A to 5B. Accordingly, it is to be understood that the presently claimed invention encompasses all four roof assembly embodiments. This is particularly significant, however, with regard to the embodiments illustrated in FIGS. 5A and 5B. Specifically, no coverboard (e.g.: OSB, Plywood, Densdeck®, HD Polyiso or Ecostorm®) is required to meet the Very Severe Hail rating of FM 4470 (Class 1).

(46) FIG. 4A shows a corrugated roof 40 onto which insulation assembly 50 is fastened. A protective coverboard 60 is secured thereover and a fleece backed membrane 70 is adhered over the top of coverboard 60. FIG. 4B is similar to FIG. 4A, but with a non-fleece membrane 72 is instead adhered over the top of coverboard 60.

(47) FIG. 5A shows a corrugated roof 40, similar to FIG. 4A, but with the protective coverboard removed. FIG. 5B is similar to FIG. 5A, but with a non-fleece membrane 74 instead adhered directly onto the top of insulation board assembly 10.