How much does it cost to plaster a room?
Enter the wall (and ceiling) area to plaster and we'll work out the bags of plaster, labour and total cost — showing exactly how many bags of Multi-Finish your area needs and why.
Tip: a wall is roughly length × height. A 4 m × 2.4 m wall ≈ 9.6 m².
| Multi-Finish plaster | 3 × 25 kg bag | £39 |
- 1Area to plaster: 30 m²
- 2Skim plaster: 30 m² ÷ 10 m² per 25 kg bag = 3 bags of Multi-Finish
- Multi-Finish covers ~10 m² per 25 kg bag at a 2 mm skim.
- Assumes a sound, flat background to skim onto.
How plastering quantities are worked out
- 1Measure the area to skim
Add the wall areas (length × height) and the ceiling (length × width) if it's being done. A typical bedroom is ~30 m² of wall plus ~12 m² of ceiling.
- 2Skim coverage
One 25 kg bag of Thistle Multi-Finish covers about 10 m² at a 2 mm skim. Bags = area ÷ 10, rounded up.
- 3Add a backing coat if needed
Bare brick or where you're building up thickness needs a bonding/undercoat first — about 3 m² per 25 kg bag at 11 mm — before the skim.
- 4Add labour
A plasterer skims roughly 35 m² a day. Labour = area ÷ 35 × the day rate.
Plastering quotes vary wildly, which makes it hard to know if you're being overcharged. Knowing the material side — a bag of Multi-Finish covers about 10 m² — lets you sanity-check a price. A 30 m² room needs only ~3 bags of plaster (under £40 of material); the rest is skilled labour. The calculator separates the two so you can see where the money goes.
Typical cost to plaster a room (indicative)
| Room | Wall + ceiling | Indicative cost |
|---|---|---|
| Small bedroom / box room | ~28 m² | £350 – £550 |
| Average double bedroom | ~42 m² | £500 – £750 |
| Living room | ~55 m² | £650 – £950 |
| Ceiling only (avg room) | ~12 m² | £180 – £300 |
Skim onto sound backgrounds. Boarding out or two-coat work costs more. Indicative — confirm with quotes.
Frequently asked questions
How much does it cost to plaster a room?+
For an average double bedroom (walls and ceiling ~42 m²), expect roughly £500–£750 to skim, including materials and labour. Smaller rooms are less; living rooms and two-coat work are more. The calculator gives a figure for your exact area.
How many bags of plaster do I need?+
One 25 kg bag of Multi-Finish covers about 10 m² at a 2 mm skim, so divide your area by 10 and round up. A 30 m² room needs 3 bags. The calculator shows this calculation and adds bonding if you choose a two-coat job.
Is it cheaper to plaster or plasterboard?+
Skimming an existing sound wall is cheapest. If the wall is in poor condition, dot-and-dab plasterboard then skim ('board and skim') can be quicker than patching and re-plastering — the calculator's 'plasterboard & skim' option estimates both.
How long does plastering take to dry?+
Fresh plaster typically takes 2–7 days to dry fully depending on thickness, ventilation and the weather. Wait until it's a uniform pale colour before misting and painting.
Related tools & guides
Want to know how these figures are calculated? See our cost methodology.
Cost figures shown are indicative estimates, not quotations. You are responsible for verifying all costs (obtain contractor quotes) and any figures submitted to a lender. ScopeWise is a documentation tool, not financial, tax, structural or planning advice. HMO compliance prompts are guidance only — confirm requirements with your local council, as standards and licensing vary by authority.