Equipment vibration shall be corrected.
Masonry surfaces above flashings shall be tuck-pointed and sealed. All horizontal masonry surfaces above the roof membrane shall be adequately protected from weather.
All pipes and condensation line supports shall be properly supported with factory supplied pipe supports or pressure treated woodblocking. All supports shall have a protection layer of not less than one layer of woodblocking Flintlastic modified bitumen membrane. The support shall be designed to allow for pipe movement and shall not be secured through the roof membrane.
Condensation lines shall be formed from ultraviolet light resistant materials and shall terminate at drains or scuppers. Condensate shall not run on the roof surface.
The practice of installing only a part of a total roof assembly, known as phasing, can be harmful to the finished roof assembly. CertainTeed will not warrant phased applications.
NOTE: Substrates with two or more existing membranes are not eligible for a CertainTeed Warranty. Extended warranties require new construction and/or complete tear-off.
Application Over an Existing Membrane
After preparing and priming the existing membrane surface spot mop with type III or type IV asphalt, forming 12" circles spaced 24" o.c., and install a Yosemite Venting Base Sheet with side laps of 2" and end laps of 6". Asphalt quantity shall be 15 lbs. per square, or greater, depending on the roughness of the existing membrane surface. Granules and grooves shall be facing down. Alternatively, mechanically attach a Yosemite Venting Base Sheet with minimum #12 diameter roofing fasteners and 3" stress plates to meet the design uplift criteria. At a minimum, mechanical attachment shall be placed 12" o.c. on a 3" lap and two staggered rows in the center of the sheet spaced 18" o.c.
Insulation shall be solid mopped to buffer sheet. Alternate base sheets may be approved on a job-by-job basis. Contact CertainTeed Technical Services with project data for consideration of alternate base sheets. Rigid insulation may be applied directly to an existing built-up membrane providing the surface has been properly prepared; there is adequate attachment of the existing roof assembly to resist design and/or code require loads and the deck has been adequately leveled to provide full adhesion of the maximum 4' x 4' insulation boards. An initial glaze coat of asphalt can fill minor variations in the deck surface and provide a more suitable surface for the application of rigid insulation board.