Rot and timber decay

The short answer

Timber decay in Scottish property is almost always the result of a moisture problem. Wet rot is localised to persistently damp timber; dry rot can spread through masonry and is far more serious; woodworm is common but often historic and inactive. Every treatment starts by removing the water source — chemical treatment without fixing the leak simply defers the problem.

What the work involves

Exposing affected timber, identifying the species of decay, removing and replacing structurally affected members, drying the structure, and where dry rot is confirmed, tracing and treating its full extent including within masonry.

Rules and consents in Scotland

Structural timber replacement may need a building warrant. Listed buildings require care in replacing historic timber. Any treatment involving biocides must be applied by a competent contractor.

What commonly goes wrong

Accepting a free survey from a treatment company as diagnosis. Independent inspection distinguishes active dry rot from a long-dead outbreak and avoids unnecessary and expensive works.

What it usually costs

Indicative ranges only, to help you judge a quote. They are not an estimate for your property — only the business doing the work can give you that.

• An independent timber and damp report is a few hundred pounds and often changes the scope of work substantially.
• Localised wet rot repair in a floor or window cill is a modest joinery cost.
• Confirmed dry rot is the expensive case, as it can require opening up masonry and replacing significant timber.
• Woodworm treatment is inexpensive but is often unnecessary where the infestation is historic.

What to do, in order

1. 1Find and fix the water source first — roof, gutter, plumbing or ventilation.
2. 2Get an independent report before instructing any treatment company.
3. 3Establish whether decay is active, and whether it is wet rot or dry rot.
4. 4Replace structurally affected timber and allow the area to dry.
5. 5Reinstate ventilation to the affected void or room.
6. 6Retain the report and guarantees — buyers' solicitors ask for them.

Local detail for the Lothians

• Dry rot is a well-known problem in Edinburgh's older tenement stock, particularly where a long-running roof or gutter leak has gone unnoticed in a shared close.
• Suspended timber floors in pre-1919 Lothians property are vulnerable when airbricks are blocked.
• Sash window cills and bottom rails on exposed elevations are the most common wet rot location in Edinburgh flats.
• Woodworm evidence in old roof timbers across the Lothians is frequently historic and inactive.

When you need a professional

A chartered surveyor with timber expertise for diagnosis, then a joiner and specialist contractor for the works.

Common questions

How do I tell dry rot from wet rot?

Dry rot produces a distinctive mycelium and can spread across and through masonry; wet rot stays in the wet timber. Correct identification matters because the remedial scope differs enormously.

Do I need a guarantee?

A specialist guarantee is useful when selling, but only alongside evidence that the underlying moisture cause was fixed.

Related pages

• Damp problems

  Telling penetrating damp, condensation and rising damp apart before spending money.

• Ventilation and airbricks

  Extract fans, trickle vents, airbricks and underfloor ventilation.

• Window repairs

  Sash and case overhaul, draughtproofing, and repairs to modern double glazing.