If you want to give your renovation project a quality look and feel then good preparation of the surfaces before decorating will be your best chance of achieving that.
If you project has been comprehensive enough to mean that your walls and ceilings have been rebuilt and re-plastered, then all you should need to do is wait until the plaster is properly dry, lightly rub it down and paint or paper over it.
But if the walls are still in place and just a bit jaded, then you’ll need to make good the damage before you start decorating.
Updating Tired Walls
Making good holes and damaged or crumbling plaster is a case of removing the bad and replacing it with the good. In the housing boom of the Eighties, textured wallpaper, such as woodchip paper and anaglypta, and textured surface coverings such as artex became very popular.
This is because they covered up a whole host of sins underneath them, and were a lot cheaper and faster than properly repairing and smoothing over the wall surface.
Today’s buyers are more knowledgeable and would see these as anachronistic aberrations, so it’s worth spending the time making good.
First remove all the bad plaster around the hole or other damage and keep chipping away until you reach plaster that’s solid and in good condition. Then remove all the loose particles with a hoover attachment and then a fine brush, and if you’ve exposed bricks, dampen them.
Then prepare filler or plaster according to the manufacturers instructions, and apply it to the area.
Use a filling knife or plasterer’s trowel to put the mix onto the wall and smooth it over, working it well into the edges. If it’s a deep area, build the filler up in layers, allowing each layer to stiffen, but not completely dry, before applying the next.
Once it’s dry, smooth down with fine sandpaper and if necessary apply a thin layer of skim plaster or fine filler. Then sand down again and apply your choice of paint or paper.
This method will work on both ceilings and walls, although in older properties you may encounter lath and plaster walls, where a layer of small thin battens (known as laths) is laid horizontally across timber uprights (or joists in the case of a ceiling) and a layer of plaster, often strengthened with horsehair, applied on top.
If the laths are broken, they will have to be patched, but if it’s a small hole, say no more than about 75cms across, the gap can be bridged with a piece of wire mesh wrapped around good laths. Then apply plaster or filler in the same way.
One problem area that’s trickier to fix is at the external corners of walls, which of course are often damaged as they are more prone to knocks. The initial steps are the same, removing damaged plaster until you reach the good stuff, then you will have to build some sort of mould to hold the new plaster at the corner.
Do this by nailing a wide batten to one edge of the corner, using a known straight edge to line it up with the good plaster on the adjacent wall. Fill the gap between the wall and the batten with filler or plaster in the usual way, up to the batten.
Then when it has completely dried, carefully remove the batten and fix it to the other side of the corner, to act as a guide for that side. Fill once more and remove the batten when the mix has dried.
If there is a large area on a corner to be repaired, it might be easier to use a length of expanded metal (mesh) angle beading. This is profiled with a 90 degree angle with a bead running down the corner and can be cut to the appropriate length.
Once fixed to the wall, usually with dabs of plaster, this will provide a solid guide against which to plaster rather than having to use battens.
However bad your walls and ceilings, remember that time spent on decent preparation will pay dividends in making it possible to achieve a quality finish to show off all your hard renovation work.