Our sales and technical team have over 20 years’ experience working with the industry leading rainwater systems available in the UK.
Expert advice
Our friendly service and competitive prices combined with a step-by-step support approach, make for easy rainwater product selection.
Nationwide delivery
Our delivery partners cover the whole of the UK (mainland only) so no matter where you are, we can get your order to you.
Premium quality
Our aluminium, steel, cast iron, plastic & GRP rainwater systems are all sourced from the leading manufacturers in the UK to ensure they are of the highest quality.
Harmer Extension Pieces suitable for an insulation thickness of between 50 -335mm.
Extension Pieces are for use in warm roof constructions, where the waterproof membrane occurs above the level of the roof deck. The Extension Piece is available with a choice of connecting membranes or screw flange.
The Extension Piece is sealed into the mouth of the insulated outlet by means of a neoprene seal.