Proctor Profoil 861 is a heavyweight, reinforced, UV-stabilised vapour control layer with an aluminium foil core which gives a high water vapour resistance of Sd 1700m. This makes it ideal for high-risk applications such as swimming pools (unaffected by chlorine) and textile factories. The aluminium foil is protected on both faces by polyethene for corrosive situations. The reinforced scrim ensures minimal tears and robustness to withstand tough site handling while the encapsulated foil ensures high vapour resistance.