Damp found on a mortgage valuation or survey: what happens next

Quick answer: If a mortgage valuer or surveyor flags damp, the lender usually wants a specialist damp report before lending in full, and may hold back part of the loan until the work is done. The next step is an independent damp survey that identifies the actual cause, because the fix, and the cost, depend entirely on whether it is condensation, rising damp, penetrating damp or a leak.

A damp comment on a survey is one of the most common reasons a house sale stalls. It rarely kills a sale on its own. What slows things down is uncertainty: nobody knows how big the problem is or what it will cost. This guide is for buyers, sellers and the estate agents keeping the sale together.

Why surveyors flag damp

Valuers and RICS surveyors take moisture meter readings and look for the visual signs: tide marks, salt staining, blown plaster, black mould, rotten skirting. A high meter reading is a reason to investigate, not a diagnosis. Meters can read high on salts, foil-backed wallpaper or masonry that is not actually wet, so the surveyor's recommendation is normally to "obtain a specialist damp and timber report".

What a lender may do

• Ask for a specialist report before confirming the offer.
• Make a retention: hold back part of the loan until the recommended work is done and checked.
• Reduce the valuation if the problem is significant.

The step that matters: an independent diagnosis

There are four main causes of damp, and each has a different fix:

• Condensation, the most common: fixed with ventilation, heating and insulation, not damp proofing.
• Rising damp, rarer than it is diagnosed: a failed or bridged damp-proof course.
• Penetrating damp: water getting in through a defect such as pointing, render, gutters or flashing.
• A leak: plumbing, a roof or a shower.

Commission a survey from a qualified surveyor who is not selling the treatment. Look for a CSRT qualification (Certified Surveyor in Remedial Treatment) or PCA membership. You want a written report with the cause, the evidence and a costed scope of work. See how much a damp survey costs and condensation or rising damp.

For sellers

If your home has had damp issues, or treatment with a guarantee, gather the paperwork early, because the buyer's conveyancer will ask. If you know a survey is likely to flag damp, a report commissioned in advance can stop a sale stalling for weeks.

For estate agents

Agents must not mislead buyers by leaving out material information they know about. When a survey flags damp, the fastest way to keep the chain moving is to get a specialist report in front of both sides quickly, with a cost they can negotiate around. Having a qualified damp surveyor you can call on is worth more than any amount of reassurance.

Get a damp survey near you

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