After the Plumber or Electrician

New pipes and cables usually go inside the walls. That means chasesWall chaseA groove cut into a wall so pipes or cables can run inside it. Afterwards it is closed with mortar or render and, once finished, cannot be seen. cut into the wall, holes around boxes and sockets, and sometimes a whole section of wall opened up to find a leak. Once the plumber or electrician has finished, the wall needs to be closed and finished so nothing shows.

What the jobs show

In one kitchen, after the old tiles and units came out, the new water and electrical points went where the new kitchen needed them. The openings in the wall were closed up, and the walls were plasteredRender (plaster)A layer of mortar (sand, cement or lime, and water) spread over brick or concrete to give a wall a straight, sound surface ready for paint or tiles., straightened and painted, ready for the new units to go up against them. In a small bathroom, the new supplies went inside the wall where the tap and basin would be fitted.

How a chase is closed

1. The pipes and cables are fixed firmly inside the chase, so they don't move.
2. Before it is closed, it is worth checking the pipes for leaks and photographing where they run.
3. The chase is filled with mortar or plaster up to the level of the wall, in more than one coat if it is deep.
4. Where a crackCrackA split or gap in render, concrete, a wall, a coating or wood. Fine cracks are usually only on the surface; ones that grow, keep reopening or run diagonally need attention. is likely to open, such as along long chases or where new plaster meets old, meshReinforcement meshA mesh or fabric, usually glass fibre or polyester, set into render, a coating or liquid waterproofing to hold it together and stop cracks from opening. goes in.
5. Filling, sandingSandingSmoothing a surface with sandpaper or a power sander to remove bumps, loose old paint or gloss, so the new paint or varnish grips well and comes out smooth., primerPrimerThe thin first coat that goes on before the main material. It binds dust, seals the pores and helps paint or waterproofing stick firmly. and paint, preferably over the whole wall. If the wall is going to be tiled, it needs a flat surface for the tile adhesiveTile adhesiveA ready-mixed cement-based mortar, sold as a powder and mixed with water, used to stick tiles to walls and floors. It is spread with a notched trowel..

The order of the trades

• Plumbing and electrics finish first, then plaster, and paint comes last. If a freshly painted wall is opened up to move a socket, the finish has to be done again.
• Agree beforehand who closes the chases and who does the finish, so nothing falls between the trades.
• Keep the photos of where the pipes and cables run. You'll need them whenever you want to drill into that wall.

After a leak

When a plumber repairs a leak inside a wall, the area around it is usually wet. It is best to let it dry before the final plaster and paint, otherwise stains and blisters may come back.