What is dry rot?
Dry rot is a malignant fungus which attacks structural timbers old and new. Dry rot is the most serious form of fungal decay which can attack structural timber, and can have serious consequences for a commercial property.
If left untreated, dry rot can spread rapidly, even through brickwork and concrete walls, to attack structural timber. The dry rot fungus, Serpula lacrymans, thrives in damp, dark, unventilated areas, growing behind panels and under floors.
In spite of the name ‘dry rot,’ dampness is a key factor. Once established, the dry rot spores can attack timber with moisture content as low as 20%. Dry rot often occurs in areas with poor roofing, water leaks and leaking gutters, and areas where rising damp and penetrating damp have occurred.
What does dry rot look like?
There are a number of signals that dry rot is beginning to take hold in structural timber. If you spot any of these signals, it is imperative that you contact a Peter Cox specialist dry rot surveyor immediately:
- A mushroom-like fruiting body coming from the wood
- Rust-coloured spore dust near these fruiting bodies
- Cracking or shrinking of the timber
- Timber becoming dry and brittle
- Timber darkening in colour
- Timber crumbling to the touch
- White, fluffy cotton wool-like growth appearing
- A mushroom-like smell
Dry rot treatment
If dry rot is detected by your Peter Cox dry rot surveyor, the first step in the dry rot treatment has to be eliminating these unwanted sources of moisture. Infected timbers will have to be removed and replaced. Peter Cox’s structural timber repair specialists will make repairs to structural and decorative timber, and retained timber will be sprayed with our fungicides to prevent reinfection.
Adjacent masonry which may be carrying the dry rot fungus will be treated, and room can be reoccupied just one hour after the dry rot treatment has been completed.
You may also wish to take preventative measures to stop damp problems such as wet and dry rot from reoccurring, such as Peter Cox’s commercial damp proofing services, or if the dry rot has manifested in underneath your property, as it often does, Peter Cox’s commercial basement waterproofing services. Basement waterproofing is a particularly good idea for a commercial property as it presents the opportunity to transform an unused space into a potential revenue generating opportunity.
For more information on dry rot, see page asking what is dry rot?
In damp, unventilated areas where dry rot can occur, structural timber is also at risk of wet rot. Though wet rot is not as serious – it needs a greater level of moisture to thrive than dry rot and has limited ability to travel through walls to attack timber – it still requires urgent treatment.
There are a number of types of wet rot fungus:
- Cellar fungus (Coniophora puteana) is a wet rot fungus usually found in damp basements, under floors and in skirting boards. It causes timber to darken and produce cracking both along and across the grain of the wood. It prefers very damp conditions in areas like basements, leaking roofs and wood floors, where there is insufficient ventilation.
- Mine fungus (Poria vaillantii) causes wood to shrink and split into cuboidal sectors. The strands are white, sometimes fern-like.
- Phellinus contiguus bleaches wood, which becomes fibrous and stringy. This is a common type of wet rot decay in external joinery timbers such as door and window frames.
Wet rot treatment
Once the source of moisture has been located and remedied, wet rot treatment is similar to dry rot treatment. Defective timbers affected by wet rot are removed and replaced, and treated with Peter Cox’s water-based fungicides and biocides.
For more information on wet rot, see the what is wet rot? page.
Peter Cox dry rot and wet rot surveys
It is imperative that you contact Peter Cox immediately upon discovering dry rot or wet rot in your commercial property. One of our specialist wood rot surveyors will identify the type of fungal decay present and the appropriate action to take.
To book a Peter Cox commercial wet rot or dry rot survey, simply fill in the form to the left of the page, or visit the contact page. If you suspect dry rot or wet rot in your home, see the domestic dry rot and wet rot control page.