Air and Water Barrier Building Panels
A method for improving the air and/or water barrier performance of a building panel is disclosed. The building panel may be a gypsum board or cement board. In particular, the board may have improved resistance to bulk water penetration or permeation while maintaining breathability with respect to water vapor.
1 . A method for improving the air and water barrier performance of a building panel, the method comprising:
providing a first facing material,
providing a board slurry on the first facing material,
providing a second facing material on the board slurry, and
providing a hydrophobic material to the first facing material, the second facing material, or both.
2 . The method of claim 1 , wherein the hydrophobic material is applied to the second facing material after being placed on the board slurry wherein the hydrophobic material is applied on a side of the second facing material opposite a side adjacent the board slurry.
3 . The method of claim 1 , wherein the hydrophobic material is applied to the first facing material prior to providing the first facing material wherein the hydrophobic material is applied on a side of the first facing material opposite a side adjacent the board slurry.
4 . The method of claim 1 , wherein the hydrophobic material is provided in the board slurry which then migrates to the first facing material, the second facing material, or both.
5 . The method of claim 1 , wherein the hydrophobic material includes a polysiloxane.
6 . The method of claim 1 , wherein the hydrophobic material comprises a polymer coating.
7 . The method of claim 6 , wherein the polymer includes polytetrafluoroethylene or a polyolefin.
8 . The method of claim 1 , wherein the first facing material, the second facing material, or both have hydrophobic properties and further wherein a hydrophilic facing material is positioned between the first facing material, the second facing material, or both and the board slurry.
9 . A method for improving the bond between a facing material and a board core, the method comprising:
providing a first facing material,
providing a board slurry on the first facing material,
providing a second facing material on the board slurry, and
providing a wetting agent to the first facing material, the second facing material, or both wherein the wetting agent is provided on a side of the facing material adjacent the board slurry.
10 . The method of claim 9 , wherein the wetting agent is applied at an interface between the second facing material and the board slurry after the board slurry is provided.
11 . The method of claim 9 , wherein the wetting agent is applied at an interface between the first facing material and the board slurry before the board slurry is provided.
12 . The method of claim 9 , wherein the wetting agent comprises a nonionic surfactant.
13 . A method for increasing the density of a board slurry adjacent a facing material, the method comprising:
providing a first facing material,
providing a gypsum slurry on the first facing material,
providing a second facing material on the gypsum slurry, and
providing a defoaming agent at an interface between the gypsum slurry and the first facing material, the second facing material, or both.
14 . The method of claim 13 , wherein the defoaming agent is applied at an interface between the first facing material and the board slurry before the board slurry is provided.
15 . The method of claim 13 , wherein the defoaming agent is applied at an interface between the second facing material and the board slurry after the board slurry is provided.
16 . The method of claim 13 , wherein the defoaming agent includes a polysiloxane.
17 . A method for minimizing the presence of air voids between a facing material and a gypsum core, the method comprising:
providing a first facing material,
providing a gypsum slurry on the first facing material,
providing a second facing material on the gypsum slurry, and
applying a vacuum across the surface of the first facing material, the second facing material, or both.