Rotten & Structural Timber Repairs

A rough rule: if the timber is carrying load — a floor joist, a structural door frame, a beam — any decay is potentially structural and worth having looked at properly, even if it looks minor on the surface. Surface mould or a slightly discoloured skirting board is usually cosmetic. If you are not sure which you are looking at, send us a photo and we will tell you honestly whether it needs a proper assessment.

Almost always further than the visible damage suggests, which is why we probe the surrounding timber with a bradawl or similar before saying where sound timber starts. Wet rot in particular tends to track along the grain from the original moisture source, and cutting back only as far as the obviously spongy section often leaves decayed timber behind a repair that then fails again within a few years.

Wet rot needs a consistently damp timber source and generally stays localised to where the moisture is — it rarely spreads far into surrounding dry timber. Dry rot is more serious: given the right conditions it can spread through masonry and plaster into timber that is not directly wet, via fungal strands that carry moisture to new areas. Dry rot findings usually need a specialist timber and damp survey in addition to the carpentry repair, since eradicating it properly is more than a carpentry job alone.

It depends on how much of the original timber is sound. Where decay is localised — a joist end, a section of a door frame — we cut back to sound timber and splice in a matching new section, which is less disruptive than removing the whole member. Where the decay runs the length of the timber, or the section needed to splice in would be nearly as long as the original, a complete new structural member is the more sensible repair.

No — we replace the damaged timber and tell you plainly what we think caused it, but diagnosing and treating the moisture source itself (a failed roof detail, blocked guttering, rising damp, a leaking pipe) is outside our scope and needs a roofer, plumber or damp specialist. Replacing timber without addressing the cause is only a temporary fix, so we would rather flag it clearly than let you assume the problem is solved.

Where the repair is a like-for-like replacement of a decayed structural member — matching the original size and specification — it often falls under permitted work rather than needing a fresh application, though it is still worth checking with Building Control in borderline cases. Where the repair also needs to carry more load than the original, or forms part of wider structural alteration, it falls under Building Regulations Part A and needs formal sign-off.

The principle is identical even though the setting is different — cut back to sound timber, splice or replace, and flag the cause. A door frame that has rotted from long-term damp or a failed seal is covered here; a frame that has split from a forced entry is a different cause and is covered on our burglary damage repairs page instead.

We carry out rotten and structural timber repairs across Berkshire, Surrey and South Buckinghamshire, including Ascot, Bracknell, Windsor, Maidenhead, Reading, Wokingham, Sunningdale, Virginia Water, Camberley, Stoke Poges and Gerrards Cross.