Damp, rot and timber
More money is wasted on damp than on any other defect in British housing, almost all of it because the wrong kind was treated. Work out what you actually have before anyone quotes you for anything.
Start with the diagnosis, not the treatment
In UK homes, condensation is by far the most common damp, penetrating damp second, internal leaks third, and true rising damp a distant fourth. The damp-proofing industry tends to work that list in reverse. If a company offering free damp surveys also sells the remedy, the survey is a sales visit — get an independent opinion before you commit to a chemical damp-proof course.
The tell-tale that settles most arguments
Check the external ground level. It must sit at least 150mm below the damp-proof course. Raised paths, decking, gravel, flower beds and render carried down past the DPC bridge it, and bridging is the single most common cause of what gets diagnosed as rising damp. It costs a few hundred pounds to fix and it is not a damp-proofing job.
On old buildings, breathability is the whole game
A pre-1919 solid wall has no cavity and no membrane. It works by absorbing moisture and evaporating it back out again — the evaporation is the damp-proofing. Wrap it in cement render, cement pointing and modern plastic paint and the moisture cannot leave, so it moves inwards. Lime mortar, lime plaster and breathable paint are not heritage affectations; they are how the wall functions.
Work it out yourself, free
No sign-up, no email, real 2026 builder rates.
Every guide on this topic
Survey Found Damp? What to Do Next, Before Anyone Quotes
Damp in your survey doesn't automatically mean rising damp or an expensive damp-proof course. Two things to check first, and how to get a straight answer before exchange.
Read the guide →-
Damp Coming Through the Bricks: What It Is and What It Costs
Damp coming through the brick is penetrating damp. Six ways rain gets through a wall, what each repair costs, and what not to pay for.
-
Air Bricks: What They Do and Why You Shouldn't Block Them
Air bricks look like spare holes in the wall, but on a house with a suspended timber floor they're doing an important job. Here's what they do, how they get blocked, and a five-minute check for yours.
-
Failed Cavity Wall Insulation: RICS Survey Findings and What It Costs to Fix
Damp patches and cold spots years after cavity wall insulation was installed usually mean it's failed. Here's what RICS surveys flag and what remedial work costs.
-
Japanese Knotweed and Your Mortgage: What Buyers Actually Need to Know
Japanese knotweed can genuinely derail a mortgage application — but the risk depends heavily on distance and management, not just presence. Here's how it actually works.
-
Timber Treatment Guarantees: What They're Worth When You're Buying
The seller says the woodworm or damp was ‘treated with a guarantee’ — but is that guarantee actually worth anything to you as the new owner?
-
Wet Rot vs Dry Rot: What Your RICS Survey Found and What It Costs to Fix
Dry rot has a fearsome reputation and a fearsome price tag to match — but is that really what your RICS survey found? Here's how to tell wet rot and dry rot apart.
-
Woodworm in a RICS Survey Report: Active Infestation or Old Damage?
Your RICS survey mentions woodworm — but are the beetles still active, or are you looking at decades-old damage? Here's how to tell, and what treatment actually costs.
-
Damp-Proofing Costs UK: What a Realistic Repair Bill Actually Looks Like
Damp survey quotes can range from £500 to over £10,000 for what sounds like the same problem. Here's what actually drives the cost and how to tell if a quote is fair.
-
Condensation and Black Mould: Causes, Fixes and What They Cost
Black mould in the corners, condensation on the windows — it's the most common damp problem in UK homes and usually the cheapest to fix. Here's how.
-
Rising Damp vs Penetrating Damp: How to Read Your RICS Survey's Damp Findings
Your RICS survey flags damp — but is it rising, penetrating, or condensation? The distinction changes the diagnosis, the fix and the cost. Here's how to tell them apart.
Need a builder’s honest take on a property or project?
Get a builder’s eyes on it first. We review RICS surveys, listings, photos and quotes, and tell you in plain English what matters and what it’s likely to cost.
“I am so grateful to Ben for peace of mind and clarity I have after using his amazing service ! I was baffled by my level 3 survey … it was like dealing with a trusted family member who is an expert in the building trade … All of this happened within less than 24 hours of my enquiry and I received a very detailed report with an experienced but realistic perspective. …”
Pay, then send it by WhatsApp or email · written review + call within 24 hours · refund if it isn’t clear