Timber decay and woodworm

What do dry-rot strands mean when they cross masonry, not just timber?

Dry rot can send strands through and across damp masonry to reach more timber. Seeing a strand on brick is a reason to treat the outbreak as able to travel, not as a patch on one skirting. It is still not a map of every joist. The Property Care Association’s guidance is that the fungus and the moisture both have to be dealt with.

Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.

What is the fuller explanation?

The fruiting body, the dust of rust-coloured spores and the strands are the signs PCA material describes around fungal decay. A surveyor may see one of them and not the others. A visual survey does not open every floor. If strands are on a wall, ask how far they were traced and what was not opened. Do not sand them off before a specialist has seen them.

Killing the fungus and leaving the leak, or fixing the leak and leaving live strands in a wall, are both incomplete. Ask the specialist what will be opened, what will be kept, and how moisture will be stopped. There is no PCA tariff for a terrace. Quotes that use a single price per room without a look are not the investigation the survey recommended.

What should you ask your surveyor?

Did you see strands, a fruiting body, or only soft timber?
How far did you trace them, and what is behind finishes?
Where is the moisture that is letting the fungus live?

What are the typical next steps?

Do not paint over strands.
Photograph them before anyone scrapes.
Instruct a timber specialist to open what the survey could not, with a written scope.

Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.

Also asked about this

Are all white growths dry rot?

No. Wet rot, mould and salts can look dramatic. Identification matters. The surveyor’s “possible” means they are not sure.

Does dry rot mean the house is unsellable?

No. It means a defect with a cause. The decision is whether you investigate before exchange or walk away. The fungus is not a legal bar.