Roof Drain Recession Plate

Abstract

One embodiment of a recessed roof drain support (recession plate) is to be mounted under structural roof sheathing at the location of a roof deck penetration for a roof drain body. The roof drain body mounting flange, when mounted to the recession plate, will be below the surface of the roof sheathing, creating a recess for a roofing membrane to flow smoothly into the clamping surface of the roof drain body, leaving no opportunity for water to stand.

I claim: 
     
         1 . An improved roof drain support plate which comprises:
 a. plywood or other structural material sized to fit between adjacent roof joists and;   b. an opening in said plywood or other structural material sized to properly support a roof drain body by its mounting flange and;   c. said roof drain support plate, hereafter referred to as a recession plate, capable of being fastened in a recessed position beneath a roof deck penetration;   whereby the top surface of said roof drain body mounting flange, once installed, is below the top surface of said roof deck, so that when waterproof roofing membrane is applied over said roof deck and clamped to said roof drain body, said roof drain mounting flange will not impede the flow of water into said roof drain.   
     
     
         2 . The roof drain roof drain recession plate of  claim 1  which further comprises;
 polyvinylchloride or other plastic surfacing on said roof drain recession plate in the area to which a plastic roof drain body would contact, such that said plastic roof drain body may be affixed with plumber's glue with solvent. 
 
     
     
         3 . The roof drain recession plate of  claim 1  which further comprises fabrication using ¾ inch nominal dimension plywood or other like structural material. 
     
     
         4 . An improved process for installing a commercially manufactured roof drain which comprises:
 a. milling a roof drain recession plate from nominal ¾ inch plywood or similar structural material and sized to fit between adjacent roof joists and;   b. milling an opening in said roof drain recession plate sized to allow attachment of a roof drain body by its mounting flange and;   c. fastening said roof drain recession plate beneath a roof deck penetration;
 whereby the top surface of said roof drain body mounting flange, once installed on said roof drain recession plate, would be recessed below the top surface of said roof deck, so that when waterproof roofing membrane is applied over said roof deck and clamped to said roof drain body, said roof drain mounting flange will not impede the flow of water into said roof drain. 
   
     
     
         5 . The roof drain installation process of  claim 4  which further comprises;
 applying polyvinylchloride or other plastic surfacing on said roof drain recession plate in the area to which a plastic roof drain body would contact and; 
 affixing said plastic roof drain body with plumber's glue. 
 
     
     
         6 . The roof drain installation process of  claim 4  which further comprises;
 clamping said roof drain body to said roof drain recession plate with threaded fasteners