What might be happening
The decision turns on load, location, amount of sound timber and whether the source of water is controlled.
Before agreeing to treatment or extensive replacement, it is reasonable to ask what has actually been found, how far the damage extends and what is allowing it to happen.
What you can look for
Ask for the limits of sound material to be identified and check what the repaired member has to support.
You do not need to start taking the building apart yourself. If access is difficult, ask the person inspecting it to explain what needs to be opened up and why. Photographs of hidden defects are useful, especially when you are comparing quotations.
Putting it right
Localised splicing can be appropriate for some joinery; load-bearing elements may need engineered repair or replacement.
Be wary of a quotation that deals only with the damaged wood and says nothing about the water or building defect behind it. Once the cause has been dealt with, the remaining timber can be checked and the necessary repairs planned.
When to call someone in
Concealing decay with filler does not restore lost structural strength.
A carpenter or joiner may be right for a local timber repair. If the problem involves a leak, you may need a plumber or roofer first. Where supporting timbers have moved, sagged or seriously weakened, get advice from someone qualified to assess the structure.
Questions worth asking
- What evidence supports the diagnosis and proposed treatment?
- Which parts of the work are essential and which are optional?
- Will you put the findings, scope and exclusions in writing?