Polymer-based composite structural underlayment board and flooring system
A building flooring system includes a plurality of polymer-based composite structural underlayment boards overlaying and secured to a building subfloor to form an underlayment layer over the building subfloor and a nonstructural finish-flooring layer overlaying and bonded to the underlayment layer. The polymer-based composite structural underlayment boards each have a polymer material core layer or a predominantly polymer material core layer that typically contains from 1% to 40% by weight filler(s) and a density between 1.6 lbs/ft 3 and 25 lbs/ft 3 . At least the top or bottom major surface of each of the polymer-based composite structural underlayment boards is overlaid by a facer that reinforces and strengthens the polymer-based composite structural underlayment board and that is generally coextensive with and bonded to the overlaid major surface of the polymer-based composite structural underlayment board.
1. A polymer-based composite structural underlayment board for use in the formation of a building flooring system underlayment layer to which a nonstructural finish-flooring layer is bonded, comprising:
a polymer material or predominantly polymer material core layer with a density between 1.6 lbs/ft 3 and 25 lbs/ft 3 ; the core layer having a length, a width, and a thickness; the core layer having a top major surface and a bottom major surface that are each defined by the length and the width of the core layer; at least one of the major surfaces of the core layer being overlaid by a facer that reinforces, stabilizes, and strengthens the polymer-based composite structural underlayment board and that is generally coextensive with and bonded to the overlaid major surface of the core layer;
wherein the polymer-based composite structural underlayment board has a compressive strength of at least 25 psi, a flexural strength (MOR) of at least 400 psi, a flexural strength (load at yield) of at least 20 lbf, and a fastener pull through strength of at least 20 lbf.
2. The underlayment board according to claim 1 , wherein:
the facer is an alkali resistant facer and the facer is bonded to the top major surface of the core layer.
3. The underlayment board according to claim 2 , wherein:
the alkali resistant facer is a mineral coated, nonwoven fiberglass mat or fiberglass scrim.
4. The underlayment board according to claim 1 , wherein:
the core layer is a predominantly polymer material core layer; the thickness of the core layer is between about 0.15 inches and about 0.75 inches; and the polymer material of the core layer is a polyisocyanurate material.
5. The underlayment board according to claim 4 , wherein:
the predominantly polymer material core layer contains between 1% and 40% by weight inorganic and/or organic filler material.
6. The underlayment board according to claim 4 , wherein:
the top and bottom major surfaces of the core layer are each overlaid by a facer that reinforces, stabilizes, and strengthens the polymer-based composite structural underlayment board and that is generally coextensive with and bonded to the overlaid major surface of the core layer.
7. The underlayment board according to claim 4 , wherein:
the polymer-based composite structural underlayment board has a water absorption rate of 4% by volume or less.
8. The underlayment board according to claim 1 , wherein:
the core layer is a predominantly polymer foam material core layer; the thickness of the core layer is between about 0.15 inches and about 0.75 inches; and the polymer material of the core layer is a polyisocyanurate material.
9. The underlayment board according to claim 8 , wherein:
the predominantly polymer foam material core layer contains between 1% and 40% by weight inorganic and/or organic filler material.
10. The underlayment board according to claim 8 , wherein:
the top and bottom major surfaces of the core layer are each overlaid by a facer that reinforces, stabilizes, and strengthens the polymer-based composite structural underlayment board and that is generally coextensive with and bonded to the overlaid major surface of the core layer.
11. The underlayment board according to claim 8 , wherein:
the polymer-based composite structural underlayment board has a water absorption rate of 4% by volume or less.
12. The underlayment board according to claim 8 , wherein:
the facer is an alkali resistant facer and the facer is bonded to the top major surface of the core layer.
13. A building flooring system, comprising:
a plurality of polymer-based composite structural underlayment boards overlaying and secured to a building subfloor and forming an underlayment layer over the building subfloor; each of the polymer-based composite structural underlayment boards having a polymer material or predominantly polymer material core layer with a density between 1.6 lbs/ft 3 and 25 lbs/ft 3 ; the core layer of each of the polymer-based composite structural underlayment boards having a length, a width, and a thickness; the core layer of each of the polymer-based composite structural underlayment boards having a top major surface and a bottom, major surface that are each defined by the length and the width of the core layer; at least one of the major surfaces of the core layer of each of the polymer-based composite structural underlayment boards being overlaid by a facer that reinforces and strengthens the polymer-based composite structural underlayment board and that is generally coextensive with and bonded to the overlaid major surface of the core layer of the polymer-based composite structural underlayment board; and
a nonstructural finish-flooring layer overlaying and bonded to the underlayment layer;
wherein each of the polymer-based composite structural underlayment boards has a compressive strength of at least 25 psi, a flexural strength (MOR) of at least 400 psi., a flexural strength (load at yield) of at least 20 lbf, and a fastener pull through strength of at least 20 lbf.
14. The flooring system according to claim 13 , wherein:
the facer of each polymer-based composite structural underlayment board is an alkali resistant facer and the facer is bonded to the top major surface of the core layer of the polymer-based composite structural underlayment board.
15. The flooring system according to claim 14 , wherein:
the alkali resistant facer of each polymer-based composite structural underlayment board is a mineral coated, nonwoven, fiberglass mat or fiberglass scrim.
16. The flooring system according to claim 13 , wherein:
the core layer of each of the polymer-based composite structural underlayment boards is a predominantly polymer material core layer; the thickness of the core layer of each of the polymer-based composite structural underlayment boards is between about 0.15 inches and about 0.75 inches; and the polymer material of the core layer of each of the polymer-based composite structural underlayment boards is a polyisocyanurate material.
17. The flooring system according to claim 16 , wherein:
the predominantly polymer material core layer contains between 1% and 40% by weight inorganic and/or organic filler material.
18. The flooring system according to claim 16 , wherein:
the top and bottom major surfaces of the core layer of each of the polymer-based composite structural underlayment boards are each overlaid by a facer that reinforces, stabilizes, and strengthens the polymer-based composite structural underlayment board and that is generally coextensive with and bonded to the overlaid major surface of the core layer of the polymer-based composite structural underlayment board.
19. The flooring system according to claim 16 , wherein:
each of the polymer-based composite structural underlayment boards has a water absorption rate of 4% by volume or less.
20. The flooring system according to claim 13 , wherein:
the core layer of each of the polymer-based composite structural underlayment boards is a predominantly polymer foam material core layer; the thickness of the core layer of each of the polymer-based composite structural underlayment boards is between about 0.15 inches and about 0.75 inches; and the polymer material of the core layer is a polyisocyanurate material.
21. The flooring system according to claim 20 , wherein:
the predominantly polymer foam material core layer contains between 1% and 40% by weight inorganic and/or organic filler material.
22. The flooring system according to claim 20 , wherein:
the top and bottom major surfaces of the core layer of each of the polymer-based composite structural underlayment boards are each overlaid by a facer that reinforces, stabilizes, and strengthens the polymer-based composite structural underlayment board and that is generally coextensive with and bonded to the overlaid major surface of the core layer of the polymer-based composite structural underlayment board.
23. The flooring system according to claim 20 , wherein:
each of the polymer-based composite boards has a water absorption rate of 4% by volume or less.
24. The flooring system according to claim 20 , wherein:
the facer of each polymer-based composite structural underlayment board is an alkali resistant facer and the facer is bonded to the top major surface of the core layer of the polymer-based composite structural underlayment board.
25. The flooring system according to claim 13 , including:
a second nonstructural finish-flooring layer intermediate the underlayment layer and the building subfloor.