A knock from a door handle, a removed shelf bracket or an old radiator pipe can leave an unwelcome gap in your wall. Most holes are well within reach of a confident DIYer, and this guide walks you through the job by size, so you know when to grab the filler and when it pays to call a plasterer.
Before you buy anything, press gently around the damage. If the surrounding plaster feels solid, you have a clean repair. If it sounds hollow, crumbles, or moves, the plaster has blown (come away from the wall behind) and a simple fill will not last.
Also check whether your wall is solid (brick or block with a plaster skim) or a stud wall (plasterboard fixed to timber). The repair method differs, and a quick tap will tell you: solid walls sound dull, plasterboard sounds hollow.
For anything up to around 50mm, a ready-mixed or powder filler does the job. Brush out loose debris, lightly dampen the edges so the filler bonds, then press it in with a filling knife, slightly overfilling to allow for shrinkage.
Deep holes are best done in two or three thinner layers rather than one thick one, letting each go off before the next. Once dry, sand back flush with fine paper (120 to 180 grit), then spot-prime before painting so the patch does not flash through the topcoat.
A hole the size of a fist in a stud wall cannot simply be filled, as there is nothing behind it. The tidiest fix is an offcut of plasterboard cut slightly larger than the hole, with the back scored so you can snap the edges into a plug that wedges in place, held with a bead of adhesive.
Alternatively, a self-adhesive aluminium patch over the hole gives a quick base to skim over. Either way, finish with two thin coats of jointing or finishing plaster, feathered well past the edges, then sand and prime.
If the plaster has blown across a wider area, if damp or salts are coming through, or if you simply want a flat, paint-ready finish over a larger patch, it is usually quicker and cheaper in the long run to bring someone in. A poor patch tends to show under low winter light, especially on the older lime plaster common in homes around Olney and the surrounding Buckinghamshire villages.
As a rough guide, a single small patch repair often falls in the region of 80 to 200 pounds, while skimming a full wall to hide multiple repairs is typically priced by the room. The right figure always depends on access, wall condition and how much making good is needed, so an on-site look is the only honest way to quote.
Filler is usually ready to sand and paint within a few hours, but fresh plaster needs to dry fully first, often several days depending on thickness and room warmth. Always seal new plaster with a watered-down mist coat before your topcoats.
Cracking usually means the filler was applied too thickly in one go, the edges were not dampened, or there is movement behind the wall. Build up in thinner layers, and if cracks return along the same line, there may be an underlying issue worth getting checked.
Filler has nothing to grip across a big gap, so it will sag or fall out. Anything beyond roughly 50mm needs a backing, such as a plasterboard offcut or a patch, before filling or skimming over the top.
Send a photo and a rough room size. Keith will come and have a look, take the measurements and quote you fair.
Tell Keith about your job and a rough idea of the work. He will come back to you with a time to come and have a look.