Release and re-seal all blisters. Make good any other defects in the roof covering. Remove all superfluous materials, dust and debris from the roof and leave in a clean and dry condition.
2. Thermal Insulation (If Required)
Install Icopal Thermazone SLM Roofboard insulation by mechanical fixing at a rate of 11 fixings per board, or by bonding in Insta-stik PU adhesive or other similar approved bonding adhesive to manufacturers recommendations.
3a. Membrane Mechanically Fixed
Install Sure-Weld TPO membrane to provide a secure and watertight roof with membrane free from wrinkles or blemishes. Side laps are mechanically fixed at centres as described on the fixing scheme-drawing ref ........ All sheets to be mechanically fixed around the perimeter and all apertures or attached to Sure-Weld pre formed metal flashing for securement.
All mechanical fixings must be Sure-Weld HP-X and pirhana plate washers and fitted in accordance with the recommend equipment to ensure correct and consistent insertion.
3b. Membrane Fully Adhered
Verify that the surfaces to receive the Sure-Weld adhered membrane are clean, dry, smooth and free from defects. During membrane installation, inspect and correct the substrate where necessary to avoid gaps between insulation boards, uneven or step off conditions. Apply the Sure-Weld Fleeceback bonding adhesive to insulation with a medium nap roller ensuring continuous and even distribution of the adhesive, avoiding puddles. Sure-Weld Fleeceback bonding adhesive must be left open until it starts to string or stick to a dry finger touch. Do not apply adhesive to lap areas which are to be hot air welded. Roll the membrane into the wet adhesive coated substrate (once foaming or stringing has occurred) avoiding wrinkles in the sheet. Immediately roll with a weighted roller to adhesive maximum contact.
Side Lap Welding
Lap side and end joints not less than 50mm ensuring that water will drain over and not into them. Seal all side and end joints by welding. If the membrane has been exposed for more than seven days, clean and dry the joint surfaces using Sure-Weld Membrane Cleaner for the whole length of the lap prior to heat welding. At end laps overlap butt edges with a 150mm wide strip of Sure-Weld Reinforced membrane and hot air weld along all edges. Apply 3mm bead of edge sealant to all cut edges of membrane and all the end laps.
Note: All roof areas being considered for overlay must be assessed for suitability by Icopal Technical Services.