Roofing systems and methods
A method includes providing a production line configured for continuous fabrication of polymer or predominantly polymer roofing boards by setting and expansion of precursor materials on a conveyor. A first polymer or predominantly polymer material foam precursor is dispensed to the production line, and allowed to rise and at least partially set to form a foam core layer for an insulation board, the foam core layer for the insulation board having a first density. A second polymer or predominantly polymer material foam precursor is dispensed to the production line and allowed to rise and set to form a core layer for a cover board, the foam core layer for the cover board having a second density greater than the first density. The combined thickness of the foam core layer for the insulation board and the core layer for the cover board is set by constraining the expansion of the combined foam precursors using a downstream forming conveyor disposed above the rising foam precursors.
1. A method for fabricating roofing boards, the method comprising:
providing a production line configured for continuous fabrication of polymer or predominantly polymer roofing boards by setting and expansion of precursor materials on a conveyor;
dispensing to the production line a first polymer or predominantly polymer material foam precursor;
allowing the first foam precursor to rise and at least partially set to form a foam core layer for an insulation board, the foam core layer for the insulation board having a first density;
dispensing to the production line a second polymer or predominantly polymer material foam precursor;
allowing the second foam precursor to rise and set to form a core layer for a cover board, the foam core layer for the cover board having a second density greater than the first density; and
setting the combined thickness of the foam core layer for the insulation board and the core layer for the cover board by constraining the expansion of the combined foam precursors using a downstream forming conveyor disposed above the rising foam precursors and positioned downstream of the dispensing of the second polymer or predominantly polymer foam precursor.
2. The method of claim 1 , further comprising providing a common facer material on top of the first polymer or predominantly polymer material foam precursor, to form a common facer between the core layer for the insulation board and the core layer for the cover board.
3. The method of claim 1 , further comprising setting the thickness of the foam core layer for the insulation board by constraining the expansion of the first polymer or predominantly polymer material foam precursor using an upstream forming conveyor disposed above the rising first polymer or predominantly polymer material foam precursor, the upstream forming conveyor positioned upstream of the dispensing of the second polymer or predominantly polymer foam precursor.
4. The method of claim 3 , further comprising providing a common facer material on top of the first polymer or predominantly polymer material foam precursor, to form a common facer between the core layer for the insulation board and the core layer for the cover board.
5. The method of claim 1 , wherein the expansion of the first polymer or predominantly polymer material foam precursor is not constrained by any forming conveyor other than the downstream forming conveyor.
6. The method of claim 5 , further comprising providing a common facer material on top of the first polymer or predominantly polymer material foam precursor, to form a common facer between the core layer for the insulation board and the core layer for the cover board.
7. The method of claim 1 , further comprising providing an upper facer material on top of the second polymer or predominantly polymer material foam precursor, to form a top facer of a composite panel comprising the insulation board and the cover board.
8. The method of claim 1 , wherein dispensing the first polymer or predominantly polymer material foam precursor comprises dispensing a foam precursor comprising polyisocyanurate.
9. The method of claim 1 , wherein dispensing the second polymer or predominantly polymer material foam precursor comprises dispensing a foam precursor comprising polyisocyanurate.
10. The method of claim 1 , wherein dispensing a first polymer or predominantly polymer material foam precursor comprises dispensing a foam precursor comprising polystyrene.
11. The method of claim 1 , further comprising cutting the cover board and the insulation board to length.
12. The method of claim 1 , further comprising installing the insulation board and the cover board on a roof.
13. The method of claim 1 , further comprising applying and bonding a bottom facer to the foam core layer of the insulation board with a reinforcing means interposed between the bottom facer and a bottom major surface of the core layer of the insulation board, the reinforcing means positioned to coincide with a fastener pattern for securing the roofing system panels being formed to a roof deck and increase a per-fastener wind-uplift pull through rating for the roofing system panels being formed.
14. The method of claim 13 , wherein the reinforcing means comprises reinforcing patches.
15. The method of claim 13 , wherein the reinforcing means comprises reinforcing strips.
16. The method of claim 1 , wherein the density of the core layer of the cover board after setting is between 6 lb/ft 3 and 25 lb/ft 3 .
17. The method of claim 1 , wherein the density of the core layer of the cover board after setting is between 4 lb/ft 3 and 25 lb/ft 3 .
18. The method of claim 1 , wherein the density of the core layer of the insulation board after setting is less than 4 lb/ft 3 .
19. The method of claim 1 , wherein the density of the core layer of the insulation board after setting is less than 2.5 lb/ft 3 .