The presence of a vapour control layer helps to maintain the airtightness of the roof.
Metal decks - loose laid polyethylene membrane
Lay vapour control layer without folds or wrinkles allowing for minimum 100mm side and end laps. Seal all laps with a suitable Tape. Turn the vapour control layer up all upstands, kerbs and penetrations etc. to maintain an air tight barrier.
Concrete / timber decks – fully adhered bitumen membranes
Prepare concrete surface using Primer. Install vapour control Layer ensuring minimum 100mm overlaps. Seal all laps and turn the vapour control layer up all upstands, kerbs and penetrations etc.