Plasterers near you

The characteristic failure of old plaster here has nothing to do with its surface. Plaster over wood lath is held on by keys — the material squeezed through the gaps between the laths, which hooks over the back and hardens there. A century of movement, vibration and the occasional leak breaks those keys, and the plaster then hangs on the wall with nothing holding it. From the front it can look perfect. Press it and it gives; tap it and it sounds hollow across a whole area rather than in one spot. Filling the visible crack on a wall whose keys have gone puts the same crack back inside a year, because what moved was the substrate. The correct repair refastens the plaster to the lath first — plaster washers and screws, or taking out and rebuilding the failed section — and only then makes the surface good. Ask which of those an offer assumes, because they are not the same amount of work.

Beyond repair, three things are bought under this heading. A skim coat is a thin finish coat across a whole wall or ceiling to make a battered surface flat again, and it is often the right answer for a room that has been patched twenty times and reads lumpy under modern paint. Cornice, mouldings and ceiling roses are the ornamental side, and older houses are often full of them: a run cornice is made by dragging a shaped profile through wet material along the wall, so restoring one means matching a profile rather than buying a length, and whether an original section survives to copy changes the task entirely. Lime plaster and polished plaster are the specialist end — lime is soft and breathable and is what a solid old wall actually wants, while polished plaster is a decorative finish built up in thin coats and burnished, priced by the wall and by how flat it starts out.

Finally, the thing nobody mentions until the day. Plaster and skim coats cure by drying, so the room’s conditions are part of the specification rather than an afterthought. Dry, heated indoor air pulls a skim off too fast, which crazes it; an unheated basement, or a closed-up room in humid weather, will not let it go off at all. Expect to be told to hold the heat steady and keep the windows shut for a day or two, or the exact opposite, and expect the room to be out of use for longer than the work itself took. When you post, say which room it is, whether it is heated, whether anything has ever leaked into that wall, and roughly when the house was built. That last answer decides which of the several different tasks on this page you are actually asking for.