CCAC Bid 1095 - Replace Roof at Library Building - Alleghen…

Community College of Allegheny County Pittsburgh, Pennsylvania

2022 Library Roofing Project

d. Bonding adhesive shall be applied using approved solvent-resistant roller or power roller equipment. 2. Field Sheet Application: a. Plan placement of field membrane to ensure water will flow over or along, but not against membrane laps and side laps. b. Begin membrane installation at low point of deck. Allow sheet to overhang roof edge a minimum of 1-1/2 inches below lower edge of wood nailer. c. Position sheeting in a manner, which provides sufficient material to facilitate flashing. The roofing membrane shall be unrolled and positioned square with the roof edge. Laps shall be shingled with, or run parallel to, the slope of the roof. d. Overlap side laps 3 inches and abut end laps. Reposition sheet when necessary. Do not stretch material unevenly. e. Install succeeding rolls in same manner. Avoid wrinkles. Reposition sheet when necessary. Do not stretch material unevenly. f. Fold sheet back so one-half (1/2) of the underside of the sheet is exposed. Ensure the sheet fold is smooth with no wrinkles or buckles. g. Apply bonding adhesive in full coverage to the substrate only. (1) The adhesive shall be applied to substrate at a minimum rate of 1-gallon per every 100 to 120 square feet. The adhesive shall be applied in a smooth even coating with no globs, puddles, voids or similar irregularities. Coverage will vary based on substrate porosity. Only areas that can be completely covered in the same day shall be coated with adhesive.

(2)

Apply adhesive to the substrate. Install membrane immediately into adhesive avoiding any air entrapment. Do not wait for adhesive to dry. Membrane must be rolled into wet adhesive. If the surface dries, re-apply bonding adhesive. Bonding adhesive shall not be applied to lap (seam) areas that are to be welded to flashings or adjacent membrane sheets by means of hot air welding procedures. If contamination occurs, remove any contaminates prior to hot air welding seams.

(3)

h.

Roll the membrane onto the adhesive coated substrate avoiding wrinkles. (1) Apply membrane across the continuous joints in top layer of insulation where feasible. Do not allow membrane laps directly over insulation joints. Insure full and continuous seal and contact between asphalt and membrane by mopping uniformly and by full brooming before the asphalt cools. Using a push broom and positive downward pressure, brush down the bonded half of the membrane sheet to achieve maximum contact. Fold back the unbonded half of the sheet and repeat bonding procedure. Apply adjoining sheets in same manner, lapping edges a minimum of 3”. Any wrinkles found in the splice area or that impedes the flow of water drainage, must be cut out, laid flat and repaired using KEE membrane and standard hot air seam welding procedures.

i. j.

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07540-9 THERMOPLASTIC MEMBRANE ROOFING

February 2022

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