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Wet and dry rot: establishing the extent before anyone sets a scope
Rot quotes vary enormously for the same outbreak, because the scope is a judgement and the person making it is usually the person being paid to carry it out. We establish what is present, how far it has actually gone and what is wetting it, and we do not tender for the work.
The two questions that determine the cost
- Which it is: dry rot can spread through masonry to reach timber elsewhere, wet rot cannot
- How far it has gone, which decides whether this is a repair or a project
- What is wetting the timber, since treatment over a live water source fails
- Whether affected members have lost structural section or merely surface condition
- Where opening up is genuinely needed, and how little of it will answer the question
Why the extent is the whole argument
Dry rot conducts its own moisture along strands and can travel behind plaster and through masonry to find timber some way from the original wet area. That is a real property of the fungus and it is also the justification offered for very large scopes of work. Both things are true, which is why the extent has to be established by following the evidence rather than assumed in either direction.
Wet rot, which is far more common, stays where the water is. An outbreak at a bay window, a joist end or a sill is a localised repair once the water is dealt with. A quote that treats a localised wet rot outbreak as a whole floor problem should be asked to demonstrate why.
How we scope it
Identification first, from the fruiting body, the strands, the spore dust and the cuboidal cracking pattern where present. Then moisture mapping to establish where the wet area actually is and where it ends. Then following the evidence outward from the visible outbreak rather than opening on principle.
Where opening up is necessary we specify precisely where and how much, so a targeted investigation answers the question rather than a general one. In listed and conservation properties that specificity matters twice over, because every opening needs justifying.
What the report is for
Buyers who have had rot flagged and are being asked to accept a five figure figure without a basis for it. Owners holding a quote they cannot evaluate. Leaseholders and freeholders disputing who is responsible for the water that caused it. Solicitors who need a scope that is defensible rather than defensive.
ATi carries out no remedial work, tenders for nothing and recommends no contractors, so the extent we report is the extent we found. That is the only reason a report of this kind carries weight with the person being asked to pay for the work.
Establish the extent independently
Identification, moisture mapping, the extent so far as it can be determined without unnecessary opening up, and a written report within 24 hours of the visit.
Book a surveyOr call 020 3355 4944.
Questions
We have two quotes for dry rot that differ by a factor of four. Why?
Because the scope is a judgement, not a measurement, and dry rot gives a reasonable justification for almost any scope: it can spread through masonry, so a cautious contractor can defend opening up a great deal. That is why an independent determination of the extent, by somebody not tendering for the work, is worth having before you accept either figure. It converts a judgement into a documented finding that both quotes can be measured against.
Do you have to open walls up to find out?
Sometimes, and less often than is assumed. Moisture mapping, the location and condition of the visible outbreak, the construction and the water source together tell you a great deal about where the fungus can and cannot have travelled. Where opening up is genuinely required, we specify exactly where and how much, so the smallest useful investigation answers the question. On a listed building that specificity is essential rather than merely helpful.
Will treatment work if the leak is still there?
No, and this is the single most important thing to get right. Fungal decay requires moisture; remove the moisture and the fungus becomes dormant and eventually dies. Apply a treatment to timber that is still being wetted and you have bought a certificate rather than a solution. Any report or quote that does not identify and address the water source is incomplete regardless of what it specifies for the timber.