Timber decay and woodworm

There is a mushroom smell in the cupboard under the stairs, but no fruiting body. What can the survey say?

It can record the smell and the fact that no fruiting body was seen in that cupboard. A smell is not identification of dry rot, and the absence of a mushroom is not a clear bill. Dry rot can be active out of sight. The survey did not open the stair carcase or the floor beside it, so it cannot map any decay from the odour alone.

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 Property Care Association treats fungal decay as a problem of timber and moisture together, not as a smell to be sprayed. A fruiting body, when it is present, is visible evidence of a fungus fruiting. A mushroom smell under the stairs, with no body, no mycelium and no soft timber seen, is a prompt to look harder at a confined space that stays damp. It is not a species identification. Other things smell musty: a leaking pipe, a wet underlay, or poor ventilation in a closed cupboard. The surveyor should say what they could see and smell, and stop there.

Do not instruct a whole-house chemical treatment because the cupboard smells. Do not ignore it because nobody found a pancake-shaped fungus on the day. Ask whether the cupboard back, the stair strings and the nearby floor were visible, and whether any timber was soft. If the answer is that fitted boards or stored boxes hid them, the limitation matters. A specialist who will look at moisture and at the concealed timber is the next step if you need to know before you commit. The home survey has not cultured the smell and has not followed strands it could not see.

What should you ask your surveyor?

What exactly did you see in the cupboard, as well as what you smelled?
Was any timber soft, or was the timber hidden?
Are you naming dry rot, or only reporting a smell and no fruiting body?

What are the typical next steps?

Do not spray the cupboard and call the smell diagnosed.
Do not stack the seller’s boxes back and forget the limitation.
If you investigate, ask the specialist to look for moisture as well as fungus. The PCA’s point is that moisture has to be dealt with.

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

Does a mushroom smell always mean dry rot?

No. It means a smell. Dry rot is identified from what is growing and the timber condition, not from the nose alone.

If a fruiting body appears later, does this survey’s silence cover it?

No. This visit did not see one. A later growth is a new fact. Do not pretend the cupboard was opened up.