Built-up roofing systems and methods

• US 6,110,846 A
• Filed: 10/29/1999
• Issued: 08/29/2000
• Est. Priority Date: 07/30/1998
• Status: Expired due to Fees

• Current Assignee: Viridian Systems, LLC
• Original Assignee: W.P. Hickman Systems, Inc. (Serefex Corp.)
• Inventors: Brzozowski, Kenneth J., Chernotowich, Ken
• Primary Examiner(s): Szekely, Peter A.
• Application Number:
  US09/430,431
• Time in Patent Office: 305 Days
• Field of Search: 442/85, 442/86, 442/258, 442/282
• US Class Current: 442/85
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/08 Homopolymers or copolymers according to C08L7/00 - C08L21/00; Derivatives thereof
• CPC Class Codes: C08L 55/02 ABS [Acrylonitrile-Butadiene-Styrene] polymers
• CPC Class Codes: C08L 95/00 Compositions of bituminous materials, e.g. asphalt, tar, pitch
• CPC Class Codes: E04D 11/02 Build-up roofs, i.e. consisting of two or more layers bonded together in situ, at least one of the layers being of watertight composition gravelling of flat roofs E04D7/00; venting or ventilation E04D13/17
• CPC Class Codes: Y10T 442/2213 Coating or impregnation is specified as weather proof, water vapor resistant, or moisture resistant
• CPC Class Codes: Y10T 442/2221 Coating or impregnation is specified as water proof
• CPC Class Codes: Y10T 442/3626 At least one layer contains bituminous material [e.g., tar, pitch, asphalt, etc.]
• CPC Class Codes: Y10T 442/3821 Coating or impregnation contains bituminous material

Abstract

In one embodiment, this invention relates to a bitumen-based built-up roofing system comprising a structural deck covered with a membrane comprising:

(A) at least two layers of reinforcement, the bottom layer being attached to said structural deck,

(B) a bitumen-based waterproofing adhesive between each layer wherein each layer is adhered to the bitumen-based adhesive between the layers,

(C) a bitumen based flood coat over the layers, and

(D) a protective layer of mineral aggregate material embedded in the flood coat, wherein the bitumen in at least the flood coat comprises a coal tar composition prepared from a blend comprising:

(1) from about 80 parts to about 98 parts by weight of coal tar having an overall float test of from about 50 seconds to about 220 seconds,

(2) from about 2 parts to about 20 parts by weight of coal tar pitch having a softening point of from about 140 to about 160° C., and

(3) from about 1% to about 20% by weight, based on the total weight of the composition, of an acrylonitrile-butadiene copolymer.

Claims

1. A bitumen-based built-up roofing system comprising a structural deck covered with a membrane comprising

(A) at least two layers of reinforcement, the bottom layer being attached to said structural deck,

(B) a bitumen-based waterproofing adhesive between each layer of reinforcement wherein each layer is adhered to the bitumen-based adhesive between the layers,

(C) a bitumen based flood coat over the reinforcement layers, and

(D) a protective layer of mineral aggregate material embedded in the flood coat, wherein the bitumen in at least the flood coat comprises a coal tar composition prepared from a blend comprising:

(1) from about 80 parts to about 98 parts by weight of coal tar having an overall float test of from about 50 seconds to about 220 seconds,

(2) from about 2 parts to about 20 parts by weight of coal tar pitch having a softening point of from about 140 to about 160°

C., and

(3) from about 1% to about 20% by weight, based on the total weight of the composition, of an acrylonitrile-butadiene copolymer.

2. The roofing system of claim 1 wherein the bottom layer of the reinforcement is attached directly to the structural deck.

3. The roofing system of claim 1 wherein the bottom layer of reinforcement is attached to one or more insulation boards which are attached directly to the structural deck.

4. The roofing system of claim 1 wherein the bottom layer of reinforcement is attached to a base sheet which is attached to the deck.

5. The roofing system of claim 1 wherein the bottom layer of reinforcement is attached to a cover board with a waterproofing adhesive, the cover board is attached to the upper layer of one or more layers of insulation, and the lower layer of insulation is attached to the structural deck.

6. The roofing system of claim 5 wherein the cover board comprises perlite, woodfiber and fiberglass.

7. The roofing system of claim 1 wherein the layers of reinforcement comprise layers selected from the group consisting of bitumen saturated organic felt, bitumen impregnated glass fiber felt, bitumen-free glass fiber felt, polyester fabric and combinations thereof.

8. The roofing system of claim 1 wherein the layers of reinforcement comprise layers of bitumen saturated organic felt.

9. The roofing system of claim 1 wherein the layers of reinforcement comprise layers of bitumen impregnated glass fiber felt.

10. The roofing system of claim 1 wherein the layers of reinforcement comprise untreated or bitumen treated layers of polyester fabric.

11. The roofing system of claim 1 wherein the coal tar (1) in the blend has an overall float test of from about 150 to about 220 seconds.

12. The roofing system of claim 1 wherein the blend comprises from about 86 parts to about 98 parts by weight of coal tar.

13. The roofing system of claim 1 wherein the blend comprises from about 5 parts to about 18 parts by weight of the coal tar pitch.

14. The roofing system of claim 1 wherein the coal tar pitch in the blend has a softening point of from about 145°

C. to about 155°

C.

15. The roofing system of claim 1 wherein the blend comprises from about 5% to 15% by weight, based on the total weight of the composition, of an acrylonitrile-butadiene copolymer.

16. The roofing system of claim 1 wherein the acrylonitrile-butadiene copolymer in the blend contains from about 20% to about 45% by weight of acrylonitrile.

17. The roofing system of claim 1 wherein the acrylonitrile-butadiene copolymer in the blend contains from about 25% to about 35% by weight of acrylonitrile.

18. The roofing system of claim 1 wherein the acrylonitrile-butadiene copolymer in the blend contains from about 5% to about 15% by weight of at least one partitioning agent.

19. The roofing system of claim 1 wherein up to about 35 parts of the coal tar (1) in the blend is replaced with a coal tar selected from coal tars having softening points of from about 52°

C. to about 60°

C. or from about 56°

C. to about 64°

C.

20. The roofing system of claim 1 wherein the acrylonitrile-butadiene copolymer in the blend has a Mooney viscosity (ML-4@100°

C.) of from about 25 to about 85.

21. The roofing system of claim 1 wherein the coal tar composition contains less than about 0.5% by weight of water.

22. The roofing system of claim 1 wherein the coal tar composition is characterized as having a softening point in the range of from about 55°

C. to about 70°

C.

23. The roofing system of claim 1 wherein the coal tar composition is characterized as having an elongation (ASTM D412) of at least about 1000%.

24. The roofing system of claim 1 wherein the mineral aggregate material is an inert material.

25. A bitumen-based built-up roofing system comprising a structural deck covered with a membrane comprising:

(A) at least two layers of reinforcement,

(B) at least one layer of insulation wherein the bottom layer of reinforcement is attached to the upper most layer of insulation,

(C) a base layer having an upper surface and a lower surface, wherein the lower most layer of insulation is attached to the upper surface of the base layer, and the lower surface of the base layer is attached to the structural deck,

(D) a separately applied bitumen-based waterproofing adhesive between each of the layers of reinforcement, between the lower most layer of the reinforcement and the upper most insulation layer, between the insulation layers, and between the lower most insulation layer and the upper surface of the base layer whereby each of said layers is adhered to the bitumen-based adhesive applied between the layers,

(E) a bitumen-based flood coat over the layers of reinforcement, and

(F) a protective layer of mineral aggregate material embedded in the flood coat, wherein the bitumen in at least the flood coat comprises a coal tar composition prepared from a blend comprising;

(1) from about 80 parts to about 98 parts by weight of coal tar having an overall float test of from about 50 seconds to about 220 seconds,

(2) from about 2 parts to about 20 parts by weight of coal tar pitch having a softening point of from about 140 to about 160°

C., and

(3) from about 1% to about 20% by weight, based on the total weight of the composition, of an acrylonitrile-butadiene copolymer.

26. A bitumen-based built-up roofing system comprising a structural deck covered with a membrane comprising

(A) at least two plied layers of reinforcement, the bottom layer being attached to said structural deck,

(B) a separately applied bitumen-based waterproofing adhesive between each layer wherein each ply is adhered to the bitumen-based adhesive applied between the plies,

(C) a bitumen based flood coat over the plied layers, and

(D) a protective layer of inert mineral aggregate material embedded in the flood coat, wherein the bitumen in at least the flood coat comprises a coal tar composition prepared from a blend comprising:

(1) from about 80 parts to about 98 parts by weight of coal tar having an overall float test of from about 50 seconds to about 220 seconds,

(2) from about 2 parts to about 20 parts by weight of coal tar pitch having a softening point of from about 140 to about 160°

C., and

(3) from about 1% to about 20% by weight, based on the total weight of the composition, of an acrylonitrile-butadiene copolymer.