Replastering a Room: Cost, Process & Timescales

Replastering is one of those jobs that unlocks everything else, you cannot paint, tile, or wallpaper properly onto a crumbling or patchy wall. The cost varies considerably depending on whether you need a simple skim coat to freshen the surface or a complete strip-and-replaster back to brick.

For a typical single bedroom (roughly 30–35 m² of wall and ceiling after windows and doors), expect to pay roughly £800–£1,620 for a full replaster or £230–£550 for a skim coat, using the rates below. Ceilings add cost because the work is slower and more demanding. The sections below break down the process, pricing and what you should realistically allow for drying before decorating.

Skim Coat vs Full Replaster

Understanding the difference between these two is the most important decision in any plastering job.

Skim coat (also called finish plaster or setting coat) applies a thin layer, typically 2–3 mm, of finishing plaster over an existing sound substrate. This is the right approach when the underlying browning coat or plasterboard is structurally intact but the surface is tired, cracked at hairline level, or textured in a way you want to smooth. It is faster and cheaper than starting from scratch.

Full replaster (or base coat + finish) involves hacking off the existing plaster back to the masonry or lath, applying a 10–15 mm backing coat (sand-and-cement render or a gypsum backing plaster such as browning or Hardwall), letting it partially set, then applying the 2–3 mm finish skim on top. This is necessary when plaster is hollow (tap it, a dull thud rather than a ring indicates debonding), when there is active damp behind the plaster, or when the existing substrate is lath and horsehair from a Victorian property that has reached the end of its life.

Plasterboard and skim is a third route common in modern renovations: dot-and-dab or batten-fix 12.5 mm plasterboard sheets to the wall, tape the joints, then skim the entire surface. This is faster than base-coat plastering, more thermally stable, and often the method of choice where walls are uneven or damp-proofing has been applied behind a membrane.

Plastering Cost per m²

The table below shows typical 2026 UK rates from a sole-trader or small firm plasterer. London and South East rates run 20–30% above these figures; Yorkshire, the Midlands and Wales tend to sit at the lower end.

These rates are supply-and-fix, including materials. Labour usually makes up most of the total; the plasterer’s materials (bonding agent, base coat, finish plaster, beads) make up the rest.

Room-by-room cost guide

The figures below assume a standard ceiling height of 2.4 m and UK average wall areas after deducting windows and doors.

The estimates multiply each area by the low and high rates in the table above, taking about a quarter of each room’s area as ceiling (the kitchen row is walls only).

Stairwells and hallways with high ceilings or restricted access attract a premium, add 15–25% for difficult access or work above 3 m.

The Replastering Process

Knowing what a competent plasterer should do helps you manage the job and spot shortcuts.

Preparation

Sound preparation adds a day but saves problems later. The plasterer should:

• Hack off loose, hollow, or failing plaster and remove to a firm edge (not just patch over)
• Remove all nails, old fixings, and wire
• Apply a bonding primer suited to the background (Thistle Bond-it or the plaster maker’s equivalent), following the maker’s instructions on dilution and drying before the base coat; skipping this step on porous or painted surfaces is a common cause of plaster delamination
• Set galvanised corner beads and angle beads at all external corners and around reveals; these should be plumb and level, not eyeballed

Base coat (browning or bonding coat)

Applied at 10–12 mm thickness in one or two passes, scratched with a devilling float to create a key, then left for the surface to firm up. On dense concrete or engineering brick, a bonding coat (Thistle Bonding Coat or equivalent) is used rather than a standard backing plaster such as browning because it adheres to low-suction surfaces.

Finish coat (skim)

Thistle MultiFinish or Finishing Plaster is the industry standard. It goes on at 2–3 mm in two thin passes, the first to fill the scratch marks, the second trowelled to a smooth finish with gradual pressure. Polishing with a damp brush as the plaster firms up produces the mirror-flat finish that takes emulsion cleanly.

Quality checks

A competent skim should be:

• Flat under a 2 m straight edge: new-home warranty standards allow only a few millimetres of deviation, for example ±5 mm in LABC Warranty’s technical manual¹
• Free of trowel marks, pitting, or cat scratches
• Consistent thickness at the edges and around beads

Drying Times Before Decorating

This is where homeowners frequently come unstuck. Fresh plaster is dark and patchy while wet and dries to an even, lighter colour (a pale pink with most gypsum finishing plasters). Painting over wet plaster traps moisture and causes paint to peel.

Accelerating drying with a fan heater set directly on fresh plaster causes surface cracking, the outside dries too fast while the inside is still wet. The correct approach is good background heat (16–20°C) and ventilation, with a fan heater set to the far side of the room. A dehumidifier can also help speed drying safely.

A mist coat, emulsion diluted 70:30 with water, applied once the plaster has dried to an even, light colour creates a porous first layer that binds without sealing. Apply two full coats of finish emulsion after that.

What to Watch Out For

Damp behind the plaster: if the existing plaster failed because of rising damp or penetrating damp, replastering over the same surface will fail again within 2–3 years. Address the source first, DPC injection, tanking, or cavity drainage, before replastering.

Cold external walls: plaster on uninsulated solid-wall external elevations can suffer thermal bridging condensation. Consider insulated plasterboard (dot-and-dab with 25–50 mm PIR backing) on cold external walls to push the dew point outward. Hacking the plaster off more than half of an external wall back to the masonry counts as renovating a thermal element under Approved Document L, and the whole wall should then be improved to at least 0.30 W/m²K where that is technically, functionally and economically feasible.² A lesser standard may be appropriate if meeting it would reduce the room’s floor area by more than 5%.²

Asbestos-containing textured coatings: Artex and other textured finishes applied before 2000 may contain asbestos.³ Do not sand or scrape without testing, an asbestos survey costs £150–£300 and is money well spent. Plastering over intact artex (rather than removing it) is a safe alternative.

Suction variation: old brick walls with patches of cement render absorb water at different rates, causing patchy drying. Ask the plasterer how they intend to control suction, bonding agents and PVA are the standard solution.

Getting Quotes

Get at least three quotes and ask each plasterer to specify whether they are quoting skim or full replaster, how they intend to prepare the substrate, and what materials they plan to use. A vague quote covering only “plastering a bedroom” without these specifics makes it impossible to compare prices or hold the contractor to quality standards.

Reputable plasterers are often booked several weeks in advance. If someone is available next week for a keen price, ask why.

Day rates for plasterers run £200–£300 per person per day in the Midlands and North, and £280–£400 in London and the South East. A competent plasterer can skim an average bedroom in half a day and base-coat-and-skim the same room in a full day to a day and a half.