restoration
Timber repair and rot treatment
Timber repair puts right rot, splits and impact damage in doors, frames, sills, fascias and structural members. Individual repairs typically cost £150 to £600, with access often costing more than the carpentry.
Typical price. £150 to £600 per repair, depending on access
What the job covers
- Splicing out wet rot
- Door and window frame repair
- Sills, fascias and soffits
- Structural timber splicing
- Woodworm-damaged timber replacement
What is involved
The first job is establishing why the timber failed, because repairing the symptom leaves the cause. Wet rot needs a water source: a failed sill drip, a blocked gutter, a cracked render, a missing mastic joint. Fix that first or the new timber goes the same way. Dry rot is a different problem with a much wider reach and usually needs a specialist rather than a carpenter.
The repair itself is a splice. Sound timber is cut back to clean material, a new piece is scarfed in and glued, and the joint is placed where water will not sit in it. Filler is for defects the size of a coin, not for a rotten sill: a filled sill looks fine for a season and then cracks along the joint. Where a whole component has gone, replacing it in matching timber is usually cheaper than a long series of splices.
Choosing someone for the job
Ask what caused the rot and what fixing it involves, because that answer tells you whether they diagnosed it or just saw soft wood. Ask whether the repair is a splice or a fill. Ask what timber and what glue.
Common questions
Repair or replace a rotten window sill?
Splice if the rot is local and the rest of the sill is sound; replace if it runs the length. A carpenter should be able to show you where the sound timber starts.
What is the difference between wet and dry rot?
Wet rot is confined to timber that is actually wet and stops when it dries. Dry rot spreads through masonry to find new timber and needs specialist treatment.
Can rotten timber just be filled?
Only small defects. Filler has no strength and does not move with the timber, so a filled structural repair fails along the joint.
How do I stop it happening again?
Deal with the water. Clear gutters, working drips under sills, sound mastic joints and paint maintained on end grain are what keep external joinery alive.