Plumbing & Sanitary Installation

Concealed pipework, drains and valves should be installed and pressure-tested before the walls and floor are tiled. Final fixtures such as basins, taps and WCs are fitted after tiling. Reversing the order usually means breaking finished tiles to fix a pipe.

Check the drainage route and slope first, because a WC or shower can only move as far as the waste pipe can fall correctly. Building management or the landlord may also need to approve changes affecting shared risers or slabs.

Water that gets behind tiles can damage plaster, ceilings below and neighbouring units. A waterproofing layer is applied to floors and wet wall zones before tiling, and is usually tested by ponding water. It is far cheaper to do properly than to repair a leak later.

A supply leak usually shows as a continuously damp spot or a running water meter even when nothing is in use. A drain leak tends to appear when fixtures are used. A plumber can isolate sections and pressure-test them to locate it accurately.

Not usually. Swapping taps, mixers and many fixtures like for like only needs access at the fixture. Opening walls is typically needed when pipes are being rerouted, replaced or when a concealed leak must be traced and repaired.