b'Roof DrainsThe Importance of Roof Drain Height Coordination and communication are essential to achieve a properly draining roof systemBy Mark S. GrahamThefollowingarticleisreprintedspecifications.Unfortunately,Following are some consider- Beforetherecenteditionsofinstallationofthickerabove-deck withpermissionfromProfessional whendesigningplumbingsys- ations and NRCAs recommenda- energy codes, this minimal above- insulation, usually in multiple lay-Roofing magazine. tems, plumbing system designerstions for proper height position- deckdrainplacementheightwasers. Insulation thicknesses of about P roperroofdrainheightand plumbing contractors usuallyingofroofdrainsabovearoofadequate for many roof system de- 3 to six inches or more may be abovearoofdeckisanhave little knowledge of a build- decks surface. signs. The codes above-deck ther- necessary to comply with current important design consider- ings specific roof system designmal insulation requirements usual- energy codes in specific regions. As and the intended thickness of anyConsiderations ly resulted in a minimal insulationa result, placing roof drains further ation and integral part of properlyabove-deck roof insulation. UnlessLeftwithoutspecificdirec- thicknessatroofdrains,andanyabove a roof deck is necessary for draining a roof systems surface.the topic of roof drains specificallytioninconstructiondocumentsadditional roof insulation thicknesssome roof system designs.For a new construction project,is raised in a project constructionor other project communication,above the roof drain easily couldThickerinsulationalsomay roof drain placement usually ismeeting, the plumbing contractora plumbing contractor likely willbe field-tapered, or shaved, by theresult in more complex configura-identified to the plumbing con- usually places roof drains based onplace a roof drain about one inchroofing contractor to create a draintions of tapered insulation to pro-tractor in the construction docu- his or her previous experience. Thisabove the roof decks surface. Forsump. vide a drain sump. In most cases, ments plumbing drawings, andmay result in unintended condi- cast-in-placeconcreteroofdecks,More current energy codes nowfield shaving insulation no longer the specific roof drain intendedtions for the roofing contractor toroofdrainssometimesareflushrequireincreasedbuildingenergyis feasible to accommodate drain isidentifiedintheplumbingaddress in the field. with a roof decks top surface. efficiency, which has resulted in theheight differences. - PMI Programs- Modified Bitumen- Built Up Systems - Metal Roof Systems- Waterproofing- Restoration- Emergency Services- Roof Anchors- Single Ply - Roof Top Decks- Sheet Metal- Inverted 10ONTARIO ROOFING NEWSISSUE 4 2020/21 THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO ORN'