Roofing systems and methods

Abstract

A roofing system includes a plurality of insulation boards adapted for overlying a roof deck to form a layer of insulation, and a plurality of cover boards adapted for overlying the layer of insulation. Each of the plurality of insulation boards has opposing planar surfaces and has a facer on at least one planar surface, and each of the plurality of insulation boards includes polyisocyanurate foam having a first polyisocyanurate foam density. Each of the plurality of cover boards has opposing planar surfaces and has a facer on at least one planar surface, and each of the plurality of cover boards includes polyisocyanurate foam having a second polyisocyanurate foam density greater than the first polyisocyanurate foam density. Each of the plurality of cover boards also includes 1% to 25% by weight one or more fillers selected from the group consisting of organic fillers and inorganic fillers

What is claimed is: 
     
         1 . A roofing system, comprising:
 a plurality of insulation boards adapted for overlying a roof deck to form a layer of insulation, each of the plurality of insulation boards having opposing planar surfaces and having a facer on at least one planar surface, and said each of the plurality of insulation boards comprising polyisocyanurate foam having a first polyisocyanurate foam density; and   a plurality of cover boards adapted for overlying the layer of insulation, each of the plurality of cover boards having opposing planar surfaces and having a facer on at least one planar surface, and said each of the plurality of cover boards comprising polyisocyanurate foam having a second polyisocyanurate foam density greater than the first polyisocyanurate foam density, wherein each of the plurality of cover boards comprises 1% to 25% by weight one or more fillers selected from the group consisting of organic fillers and inorganic fillers.   
     
     
         2 . The roofing system of  claim 1 , wherein at least one of the one or more fillers in each of the plurality of cover boards is selected from the group consisting of powdered fillers, liquid fillers, and fiber fillers. 
     
     
         3 . The roofing system of  claim 1 , wherein at least one of the one or more fillers in each of the plurality of cover boards is selected from the group consisting of fiber reinforcements, fungi growth-inhibiting agents, and fire-retardants. 
     
     
         4 . The roofing system of  claim 1 , wherein at least one of the one or more fillers in each of the plurality of cover boards is selected from the group consisting of limestone (CaCO 3 ), fiberglass, recycled polyisocyanurate dust, extenders, plasticizers, ground up foam insulation, ground up rubber, and wood dust. 
     
     
         5 . The roofing system of  claim 1 , wherein each of the plurality of insulation boards comprises 1% to 25% by weight one or more fillers selected from the group consisting of organic fillers and inorganic fillers. 
     
     
         6 . The roofing system of  claim 5 , wherein at least one of the one or more fillers in each of the plurality of insulation boards is selected from the group consisting of powdered fillers, liquid fillers, and fiber fillers. 
     
     
         7 . The roofing system of  claim 5 , wherein at least one of the one or more fillers in each of the plurality of insulation boards is selected from the group consisting of fiber reinforcements, fungi growth-inhibiting agents, and fire-retardants. 
     
     
         8 . The roofing system of  claim 5 , wherein at least one of the one or more fillers in each of the plurality of insulation boards is selected from the group consisting of limestone (CaCO 3 ), fiberglass, recycled polyisocyanurate dust, extenders, plasticizers, ground up foam insulation, ground up rubber, and wood dust. 
     
     
         9 . The roofing system of  claim 1 , wherein the second polyisocyanurate foam density is between 6 lbs/ft 3  and 25 lbs/ft 3 . 
     
     
         10 . The roofing system of  claim 1 , wherein the second polyisocyanurate foam density is between 4 lbs/ft 3  and 25 lbs/ft 3 . 
     
     
         11 . The roofing system of  claim 1 , wherein the first polyisocyanurate foam density is less than 4 lbs/ft 3 . 
     
     
         12 . The roofing system of  claim 1 , wherein the first polyisocyanurate foam density is between about 1 lbs/ft 3  and about 3 lbs/ft 3 . 
     
     
         13 . The roofing system of  claim 1 , wherein the facers comprise glass fiber. 
     
     
         14 . The roofing system of  claim 1 , wherein each of the plurality of cover boards is bonded to a respective one of the plurality of insulation boards to form a roofing panel composite. 
     
     
         15 . The roofing system of  claim 1 , further comprising a waterproofing membrane adapted for overlying the layer of cover boards. 
     
     
         16 . The roofing system of  claim 1 , wherein the greater polyisocyanurate foam density of the plurality of cover boards provides for a compressive strength to resist deformation.