Multiple immediate pass application of high thickness spray foams

Abstract

A method of applying a closed cell spray foam insulation may include spraying a first layer of a closed cell spray foam insulation into a wall cavity. A B-side mixture of the closed cell spray foam insulation may include a polyol blend having a polyester polyol having a functionality of at least about 3.0 and a polyether polyol. The method may include spraying at least one additional layer of the closed cell spray foam insulation against the first layer within 5 minutes of spraying the first layer.

What is claimed is: 
     
         1 . A wall cavity, comprising:
 a plurality of structural support members coupled together to form a frame;   a wall board attached to an exterior side of the frame to form an exterior wall or surface of the structure, wherein the plurality of structural support members and the wall board define a wall cavity; and   a plurality of layers of a spray foam insulation positioned within the wall cavity, the spray foam insulation comprising a polyester polyol having a functionality of at least about 3.0 and a polyether polyol.   
     
     
         2 . The wall cavity of  claim 1 , wherein:
 each layer of the spray foam insulation comprises a density of between about 1.9 pcf and 3.0 pcf across an entire thickness of the layer.   
     
     
         3 . The wall cavity of  claim 1 , wherein:
 each layer of the spray foam insulation exhibits a dimensional stability of less than about ±15% volumetric change at 70° C. at 97% relative humidity across an entire thickness of the layer.   
     
     
         4 . The wall cavity of  claim 1 , wherein:
 the spray foam insulation has an R value of at least 6.0 per inch.   
     
     
         5 . The wall cavity of  claim 1 , wherein:
 the plurality of layers comprise 4 layers;   each of the 4 layers is between about 1.5 and 2.0 inches thick; and   a combined R value of the plurality of layers is at least 49.