What damp proofing costs

Typical prices

• Chemical damp proof course: £60 to £120 per linear metre.
• Whole-house chemical course: £650 to £3,400. A typical home is about £1,250.
• By house type: terraced £350 to £450, semi-detached £650 to £950, detached £1,700 to £2,200.
• Physical membrane: £80 to £140 per m².
• Tanking slurry: £70 to £120 per m².
• Replastering: £30 to £70 per m².
• Independent damp survey: £150 to £600.

What is usually extra

Surveys and replastering are usually extra to a damp proof course quote. Redecorating comes after the plaster has dried, which takes weeks.

London and the South East labour costs run 20 to 40% above the UK average.

What changes the price

The length of wall, wall thickness, whether old plaster must be stripped, access to the walls, and how much timber has decayed all affect the cost. Terraced houses are cheaper than detached ones because there is less wall to treat.

Get at least two written quotes, and make sure each one says whether it includes the survey, replastering and the guarantee.

The cause matters more than the quote

Many jobs need a gutter repair, a pointing job or better ventilation, not injection. These cost far less than a damp proof course. Condensation, the commonest cause of mould, is not fixed by a damp proof course, so avoid paying for one without evidence of rising damp.

Pay for an independent survey before accepting a quote, and be wary of a free survey from a firm that sells the treatment.

Guarantees

Guarantees typically run 10 to 30 years. Insurance-backed options protect you if the contractor stops trading, and PCA members can offer them through QANW. Ask for the guarantee in writing, with what it covers.

Renters and councils

If you rent, your landlord pays for damp repairs. Social tenants have Awaab's Law time limits, and private tenants can ask the council's private sector housing team to inspect. Councils do not fix damp in private homes. See damp proofing for how a specialist works, and the DIY guide for condensation.