Dry & Wet Rot

Dry rot and wet rot are forms of timber decay caused by excessive moisture. They commonly develop as a result of water ingress from leaks, flooding, defective guttering, or prolonged damp conditions. Rot can also occur where timbers are in contact with damp masonry due to poor ventilation or the absence of an effective damp-proof course.

At Bristol Damp Solution, we provide professional surveys to identify timber decay, determine the underlying moisture source, and specify appropriate remedial works.

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Where Rot Is Commonly Found

Timber decay is most often discovered in hidden or poorly ventilated areas, including:

  • Sub-floor voids beneath suspended timber floors

  • Roof spaces

  • Behind wall linings or joinery

  • Areas affected by long-term damp or leaks

Because rot frequently develops out of sight, early professional assessment is essential.


Understanding Wet Rot

Wet rot remains localised to the source of moisture and typically affects timber that is visibly damp. Common characteristics include:

  • Darkened or softened timber

  • A wet or spongy appearance

  • Shallow cuboidal cracking along the timber surface

Wet rot does not usually spread beyond the damp area but can still compromise the structural integrity of affected timbers if left untreated.


Understanding Dry Rot

Dry rot is a wood-destroying fungus capable of spreading beyond the original moisture source. Spores, which are always present in the atmosphere, germinate when they land on damp timber under suitable conditions.

Dry rot growth may include:

  • Grey or white fungal strands (mycelium)

  • Cotton wool–like growth across timber surfaces

  • Deep cuboidal cracking within the timber

  • White or grey skin-like growths on walls or masonry

In advanced cases, a fruiting body (sporophore) may develop. This often appears as a fleshy, pancake-like structure with orange or ochre colouring and can release reddish-brown spores, visible as a fine dust in still conditions.

Dry rot can also grow through plaster, mortar and masonry in search of moisture, making accurate diagnosis and full assessment critical.


Survey, Assessment & Quotation

It is not usually possible to determine the full extent of dry or wet rot without a detailed survey. As decay may spread into concealed areas, we often recommend an exposure survey of adjoining spaces to avoid unforeseen issues.

Following inspection, we provide:

  • A clear report outlining findings

  • Identification of moisture sources

  • A fixed-price quotation for all identified works

Each property is assessed individually, as treatment specifications depend on factors such as severity, access and construction type.


Treatment & Remedial Works

Where necessary, remedial works may include:

  • Removal of affected floor and joinery timbers

  • Sterilisation of surrounding masonry

  • Replacement of joists, floorboards, skirting boards or other structural elements

Most works cause minimal disruption, and vacating the property is uncommon, although this depends on the extent of decay and access requirements.


Addressing the Cause Is Essential

Effective treatment of dry or wet rot depends on resolving the underlying moisture issue. Without this, decay may return. Our survey-led approach ensures both the cause and the damage are properly addressed.

If you’re concerned about timber decay within your property, a professional survey will provide clarity and a clear route to remediation.