Fleece-Back TPO Roofing

A fully adhered roofing system bonds the entire membrane directly to the roof substrate using liquid or spray-applied bonding adhesive.

1. 1. Substrate Preparation

   Clean and smooth: Ensure the roof deck, insulation, or cover board is clean, dry, smooth, and free of dust, loose gravel, or sharp debris.
   Repair defects: Fix wet or damaged insulation flush to the plane, and seal gaps or joints in cover boards (typically keeping board joints to 1/4 inch or less).
   Temperature check: Store and apply adhesives when temperatures are generally above 40°F (4°C) or per manufacturer specifications.

2. 2. Membrane Positioning and Relaxing

   Unroll and layout: Position the membrane panels over the substrate, starting from the low point or per project specs, and allow the material to relax for 15 to 30 minutes so it lays flat.
   Overlap allowances: Align the sheets with the required side overlaps (typically 3 to 6 inches).
   Fold back half: Fold half of the membrane sheet back over itself lengthwise to expose the bottom side and the deck below.

3. 3. Applying Bonding Adhesive

   Apply to both surfaces (or substrate per system): Roll, spray, or brush the approved bonding adhesive evenly across the exposed substrate and, depending on the manufacturer guidelines, onto the back of the membrane. (Note: Do not apply adhesive directly into the overlap seam areas).
   Flash-off period: Allow the adhesive to dry or “flash off” until it becomes tacky (does not string or stick heavily to a dry finger touch).

4. 4. Mating and Rolling the Membrane

   Embed the sheet: Carefully roll or “flutter” the coated membrane back into the wet/tacky adhesive to avoid wrinkles or air pockets.
   Broom and roll: Immediately apply heavy pressure using a stiff-bristle push broom, followed by rolling the entire bonded surface with a heavy steel roller (typically a minimum 100 lb roller) to ensure 100% full contact.
   Repeat: Fold back the unbonded half of the sheet and repeat the adhesive application, flash-off, and rolling process for the rest of the panel.

5. 5. Seams and Details

   Heat weld or tape seams: Overlap adjoining sheets and join them using hot-air welding.
   Probe seams: Once cooled or set, mechanically probe all welded or taped seams with a seam tester to check for voids or unbonded edges, repairing any deficiencies immediately.
   Flash penetrations: Detail roof curbs, walls, drains, and pipe penetrations using manufacturer-approved flashing membranes, cut-edge sealants, and termination bars.