Drainage Adaptors
Drain adaptors join new plastic pipe to whatever is already in the ground, whether clay, cast iron or a size no longer made. Flexible couplers and drainage fittings cover 105mm to 165mm, so a repair or an extension can meet the existing run without breaking further back. Part of underground drainage.
Free delivery on orders over £150 inc VAT.
22 UK Branches
Choosing Drainage Adaptors
Frequently Asked Questions
With a flexible coupler sized to both outside diameters. Old clay, pitch fibre and cast iron were made to different sizes from modern plastic, so a straight socket will not seal. Measure the outside diameter of the existing pipe at a clean cut — not the bore — and match a coupler to that figure.
Granular material — pea shingle or similar — laid to an even bed so the pipe is supported along its whole length rather than bridging between high spots. Backfill in layers around and over it before any heavier material goes in. Pipe laid straight onto lumpy dug material is what cracks later under load.
Put an inspection chamber at every junction and every change of direction, and avoid tight turns — two 45 degree bends take a corner better than one 90. Keep chambers accessible at finished ground level with a cover that lifts by hand. A run you cannot rod is a run that gets dug up.
110mm covers almost every house run, foul and surface water alike. 160mm is for a larger building, a shared run serving several properties, or where an existing 160mm line has to be matched. Oversizing is not a safe default — a pipe running part full at low velocity is more likely to silt up.