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Damp treatment cost calculator

Genuine rising damp treatment in the UK typically costs £300 to £1,000 per wall for a chemical damp proof course, or £1,000 to £3,000 and up per room once replastering is included, based on published trade price guides. Most household damp is actually condensation, which usually needs ventilation rather than any of that, so this calculator starts by checking which problem you really have.

Answer the questions below for an indicative range. It is arithmetic on published UK trade ranges, not a quote, and it will honestly tell you when the likely answer is that you do not need paid treatment at all. The right next step is always an independent diagnosis first, then the Property Care Association member search if work is genuinely needed. For a fuller breakdown of what shapes the bill, read our damp proofing cost guide.

Your situation

1. What kind of damp does it look like?

Misting windows, black mould spots, worse in winter Mould in corners, behind furniture or around windows. This pattern is usually condensation. A tide mark on a ground-floor wall, up to about 1 metre Damp rising from the floor with a visible line, salts or peeling paint low on the wall. This pattern points at rising damp. A damp patch that grows after rain, at any height Often below a gutter, around a window or on a wall that faces the weather. This pattern points at penetrating damp. Not sure Honest answer for most people. We will point you at the right next step.

What moves the price

What is actually wrong: condensation is usually fixed with ventilation and habits, a leak with a repair, and only confirmed rising damp justifies a damp proof course.
Replastering is often the largest part of a rising damp bill, frequently more than the damp proof course itself.
Wall length and access: a long external wall costs more than a short internal one.
Region, with London and the South East typically at the higher end of the ranges.
Who diagnosed it: a firm that sells the treatment has an incentive to recommend it. Pay for an independent survey first.

Damp and your health

The NHS advises that damp and mould in the home are linked to respiratory problems, respiratory infections, allergies and asthma, and that babies, children, older people and anyone with an existing skin or breathing condition are more likely to be affected. If damp or mould may be affecting your health, read the NHS guidance on damp and mould and speak to a GP if you are concerned. This page is general information, not medical advice.

Frequently asked questions

How accurate is this damp cost calculator?

It is an indicative range built from published UK trade price guides, not a quote. Real prices vary with wall length, access, your region and what a survey actually finds, so always get an independent diagnosis and then written quotes before committing to anything.

Why does the calculator keep telling me I might not need damp proofing?

Because most household damp is condensation, which is fixed with ventilation, heating habits and moisture control rather than building work. The Property Care Association warns that damp is widely misdiagnosed, and a damp proof course does nothing for condensation. Telling you that before you spend is the point of the tool.

Who should I actually call about damp?

Start with an independent damp survey from someone who will not sell you the treatment, then use the Property Care Association member search to find a qualified specialist if work is genuinely needed. Avoid committing on the strength of a free survey from a firm that profits from the recommendation.

Is damp bad for my health?

It can be. The NHS says damp and mould are linked to respiratory problems, respiratory infections, allergies and asthma, with babies, children, older people and those with existing conditions most at risk. If damp is affecting your health, see the NHS guidance and talk to a GP, and deal with the moisture source.

Sources

Oliver Mackman

Editor, HomesAndHedge

Oliver Mackman is the editor of HomesAndHedge and is accountable for its editorial standards and sourcing. He ensures every claim is backed by a named source such as the Property Care Association, the RHS, the NHS or gov.uk, and that the site is clear about when a job needs a qualified professional.

Last reviewed: 11 June 2026