Top side venting of lightweight concrete in roof systems

Abstract

An assembly and method for venting a flat or low sloped roof system eliminates the need for a base sheet membrane and fasteners and provides a spaced arrangement of V-grooves formed in the top surface of a new or existing lightweight concrete deck. The V-grooves allow moisture to migrate to the perimeter of the roof and exit the roof system. Instead of attaching a base sheet membrane to the lightweight concrete deck using penetrating fasteners, the roof membrane plies are attached directly to the primed lightweight concrete deck by self-adhesion, heat welding or with the use of cold adhesives. This prevents damage to the structural integrity of the underlying lightweight concrete, while providing an improved roof venting system.

1 . A roof system for installation on a roof structure of a building comprising:
 a lightweight insulating concrete deck applied on the roof structure, and said lightweight insulating concrete deck including a top surface;   an arrangement of grooves formed in said top surface of said lightweight insulating concrete deck, and said grooves being structured and disposed for directing moisture and liquid to the perimeter of the roof structure; and   at least one layer of roof membrane attached to said top surface of said lightweight insulating concrete deck.   
   
   
       2 . The roof system as recited in  claim 1  wherein said grooves are arranged in spaced, parallel relation on said top surface of said lightweight insulating concrete deck. 
   
   
       3 . The roof system as recited in  claim 1  wherein said grooves are at least 0.5 inch deep. 
   
   
       4 . The roof system as recited in  claim 1  wherein said grooves are between a 0.5 inch and 1.0 inch deep. 
   
   
       5 . The roof system as recited in  claim 1  wherein said grooves are arranged at spaced, parallel intervals of between 3 inches and 12 inches apart. 
   
   
       6 . The roof system as recited in  claim 1  wherein said at least one layer of roof membrane is attached directly to said top surface of said lightweight insulating concrete deck by self adhesion. 
   
   
       7 . The roof system as recited in  claim 1  wherein said at least one layer of roof membrane is attached directly to said top surface of said lightweight insulating concrete deck by heat welding. 
   
   
       8 . The roof system as recited in  claim 1  wherein said at least one layer of roof membrane is attached directly to said top surface of said lightweight insulating concrete deck by a cold adhesive. 
   
   
       9 . The roof system as recited in  claim 1  further comprising:
 a plurality of layers of roof membrane attached directly to said top surface of said lightweight insulating concrete deck.   
   
   
       10 . A roof system for installation on a roof structure of a building comprising:
 a lightweight insulating concrete deck applied on the roof structure, and said lightweight insulating concrete deck including a top surface;   an arrangement of grooves formed in said top surface of said lightweight insulating concrete deck, each of said grooves having a V-shaped cross-sectional configuration and said grooves being structured and disposed for directing heat and moisture to the perimeter of the roof structure; and   at least one layer of roof membrane attached to said top surface of said lightweight insulating concrete deck.   
   
   
       11 . The roof system as recited in  claim 10  wherein said grooves are between 0.5 inch and 1.0 inch deep. 
   
   
       12 . The roof system as recited in  claim 10  wherein said grooves are arranged at spaced intervals of between 3 inches and 12 inches apart. 
   
   
       13 . The roof system as recited in  claim 10  wherein said at least one layer of roof membrane is attached directly to said top surface of said lightweight insulating concrete deck by self adhesion. 
   
   
       14 . The roof system as recited-in  claim 10  wherein said at least one layer of roof membrane is attached directly to said top surface of said lightweight insulating concrete deck by heat welding. 
   
   
       15 . The roof system as recited in  claim 10  wherein said at least one layer of roof membrane is attached directly to said top surface of said lightweight insulating concrete deck by a cold adhesive. 
   
   
       16 . The roof system as recited in  claim 10  further comprising:
 a plurality of layers of roof membrane attached directly to said top surface of said lightweight insulating concrete deck.   
   
   
       17 . A method for venting a flat or low sloped roof system comprising the steps of:
 applying a lightweight insulating concrete deck to the top roof deck structure on a building;   forming an arrangement of grooves in a top surface of said lightweight insulating concrete deck; and   attaching at least one layer of roof membrane directly to said top surface of said lightweight insulating concrete deck.   
   
   
       18 . The method as recited in  claim 17  wherein said step of forming said arrangement of grooves in said top surface further comprises:
 moving a rake having a plurality of groove forming blades over said top surface of said lightweight insulating concrete deck during a finishing step of applying said lightweight insulating concrete deck to the top roof deck structure.   
   
   
       19 . The method as recited in  claim 17  wherein said step of forming said arrangement of grooves in said top surface further comprises the step of:
 cutting said arrangement of grooves with a rotary saw.   
   
   
       20 . The method as recited in  claim 17  wherein in each of the grooves in said arrangement of grooves has a V-shaped cross-sectional configuration and a depth ranging between 0.5 inch and 1.0 inch.