Wet rot under floor boards

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Wet Rot Treatment

Wet Rot Treatment Specialists Near You

If you see signs of decay or damp in the timber in your home, our expert team is here to help. At Peter Cox, we’ve been diagnosing and delivering trusted solutions for wood rot problems for decades.

Whether you're dealing with early-stage decay or widespread damage, our nationwide network ensures that there's always a wet rot specialist nearby, ready to assess your property and provide a solution.

Book a professional wet rot survey today and take the first step towards protecting your home.

What is Wet Rot?

Wet rot is a form of timber decay caused by fungal growth in persistently damp wood. Unlike dry rot, it remains localised to the source of moisture and won't spread through masonry. The most common fungi responsible are - Coniophora puteana (Cellar fungus) and Fibroporia vaillantii (Mine fungus). These fungi use enzymes to digest the wood's structure, weakening it over time.

What Are the Signs of Wet Rot?

Spotting the symptoms early helps prevent severe structural damage. If you recognise any of the following, it may be time to consider professional wet rot treatment.

Wet Rot Fungus

Wet rot fungus grows in stages. Early in its life cycle, it develops hyphae, which resemble spider silk. Depending on the specific genus of wet rot growing, the colour will vary from brown to white.

As the hyphae makes mass, it coalesces to form mycelium and this is often accompanied by a musty smell.

Fruiting bodies (Sporophores) are much rarer and less obvious with wet rots, when compared to dry rot. They are often much smaller.

Localised Timber Decay

Alongside potential structural damage, timber features such as skirting boards, window sills, and floorboards often exhibit physical signs of decay caused by wet rot, including damaged paintwork and visible fungal growth.

To assess whether wet rot has affected the timber, use a fine screwdriver to insert into the wood. If it easily penetrates, there is likely an issue with rot in the timber.

Damp Smell Associated With Wet Rot

Wet rot does not have a distinctive smell, but the damp conditions that lead to fungal outbreaks often create musty odours. These smells should alert you to a possible hidden issue in your property.

If you notice a persistent damp smell and can’t identify the source, it’s best to contact a qualified damp surveyor to diagnose the problem.

Timber Lightens or Darkens in Colour

Wet rot can cause timber to change colour, either darker or lighter, depending on whether one or two enzymes are used to digest the wood. This typically occurs along with a weakening of the timber’s structure, rendering it soft or spongy to the touch.

Cuboidal Cracking

Fungal enzymes can break down the fibres in timber, weakening structural elements like floorboards or beams. In advanced cases, wet rot causes the wood to split into cube-like segments, a condition known as cuboidal cracking. These cubes are usually much smaller than those seen in dry rot decay.

Our Wet Rot Treatment Services

Our approach to wet rot treatment is designed to provide long-lasting protection and peace of mind. Once a specialist has diagnosed the extent of the issue through a detailed wet rot survey, we follow a proven, step-by-step process to eliminate the problem at its source:

  • Identify and eliminate the moisture source: - From plumbing leaks to penetrating damp, our technicians will locate and resolve whatever is allowing excess moisture to damage your timber.

  • Remove decayed timber: - Any unsalvageable wood is removed carefully to prevent structural failure and spread of the fungus.

  • Apply targeted treatments: - We treat surrounding areas with high-grade fungicidal and preservative solutions to neutralise any remaining spores and prevent recurrence during the drying out period (as required).

  • Repair or replace timber: - Depending on the severity, we’ll reinforce structural areas or splice in new, treated wood to restore integrity.

  • Leave your home protected: - Our work is backed by a 20-year guarantee for qualifying treatments, ensuring your home remains safeguarded against future outbreaks.

If you're unsure whether you're dealing with wet rot, dry rot, or another form of timber decay, our experts are here to help. Book a professional inspection and let our specialists tailor the proper treatment for your property.

We back our treatment for wet rot with a 20-year guarantee.

The Importance of a Wet Rot Survey

A professional wet rot survey is the essential first step. It determines the extent of the decay and informs the best course of action. A survey will help you to understand your options, costs, and timeframes before committing to repairs.

“A thorough survey will identify, backed by evidence, whether the problem is wet or dry rot. This will allow us to provide recommendations for remedial repair. The first step is always to remove the source of moisture, and a quick response will prevent further damage, saving time, money and disruption in the long run.” – Steve Jameson, National Operations Manager.

Why Choose Peter Cox's Wet Rot Specialists?

  • Decades of timber treatment experience
  • Qualified accredited wet rot specialist teams across the UK
  • 20-year wet rot treatment guarantees
  • Fully insured and TrustMark approved
  • £25 discount when booking online

Hear from Our Customers

Wet Rot FAQs


  • What Causes Wet Rot?

    Wet rot is caused by excess moisture in timber, usually due to poor ventilation, plumbing leaks, rising damp, or defective roofing and guttering. When wood remains damp over time, typically at a moisture content of 30% or higher, it creates the ideal conditions for fungal spores to germinate and grow.

    Common sources include broken pipes, overflowing gutters, condensation build up, or structural issues that allow water to seep in. Once wet conditions persist, the wet rot fungus begins to break down the timber, often unnoticed. Preventing this starts with keeping your property dry, ventilated, and well-maintained.


  • Where Does Wet Rot Grow?

    Wet rot typically develops in timber with a moisture content between 30% and 60%, often due to hidden leaks or inadequate ventilation. Common culprits include faulty plumbing, damaged gutters, and defective external pipework that allow water to seep into wooden structures.

    Because the conditions that cause wet rot are often out of sight, the fungus tends to grow in concealed areas of a property. It’s frequently found in damp basements, under floorboards, behind skirting boards, and around leaking bathrooms or appliances, such as baths, toilets, and washing machines.


  • What's the Difference Between Wet Rot and Dry Rot?

    • Wet rot is caused by various fungi and stays confined to the area where excess moisture is present. Dry rot, however, is caused by a single species, Serpula lacrymans, which spreads aggressively across timber, masonry and brick surfaces in search of new timber to consume.
    • Dry rot can travel far beyond its original moisture source, making it far more destructive than wet rot, which does not spread once the wood dries out.
    • Wet rot requires a higher moisture content (usually around 30–60%) to grow, whereas dry rot spores can begin germinating at a moisture content of 20–30%.
    • Both types of wood rot thrive in damp environments and often display similar signs, which is why identifying the specific kind of decay can be challenging without the help of a professional wet rot survey.

  • What Are the Types of Wet Rot?

    Wood rot is split into two broad groups:

    • White rot – When the fungus attacks timber, the decay can appear as a white discolouration. This occurs as the fungus breaks down both the lignin and cellulose in the wood. As a result, the wood structure is destroyed and becomes fibrous, leaving a pale appearance in its place. White rot is often soft and spongy to the touch.
    • Brown rot – This type of wet rot only digests the cellulose in wood, leaving the lignin behind. The result is wood that retains a darker, brownish appearance. Brown rot often causes the timber to crack and shrink, making it dry and brittle.

  • Is Wet Rot Dangerous?

    The presence of wet rot suggests that at least part of your property has a moisture problem. While the fungus itself isn’t harmful to human health, the large numbers of spores present may aggravate hayfever or asthma symptoms. The danger lies in what it does to your home.

    Because wet rot often develops in hidden or hard-to-reach areas, it can go unnoticed for long periods. During that time, it steadily weakens affected timber’s, making floors, joists, or structural beams brittle, unstable, and at risk of collapse. If left untreated, wet rot can lead to serious and costly damage to your property’s structure.


  • Can I Treat Wet Rot Myself?

    Minor wet rot issues in decorative timber, such as window ledges or skirting boards, may seem manageable with over-the-counter products. These typically include fungicidal treatments and wood hardeners designed to halt fungal activity and reinforce weakened areas. If the decay is minor and localised, and the source of moisture is obvious (like a leaking appliance), some homeowners attempt DIY wet rot treatment.

    However, once wet rot affects structural timber, or if the source of damp is hidden or persistent, repairs become more complex. Replacing timbers or treating inaccessible areas without the right tools and knowledge can exacerbate the problem or simply allow it to recur.

    The most significant risk with DIY attempts is failing to address the underlying moisture issue. If the damp conditions aren’t fixed, the fungus will return. That’s why it’s always best to consult a qualified wet rot specialist, especially if you're unsure where the rot is coming from or if it's affecting areas like floor joists, beams, or basements.

    DIY repairs rarely work long-term. Only a qualified wet rot specialist can provide guaranteed, lasting results.


  • What Does Wet Rot Treatment Cost?

    The cost of wet rot treatment varies widely depending on the property and severity of the damage. Since every case is unique, it's challenging to provide an accurate estimate without first understanding the size, scale, and extent of the problem.

    In some situations, the wet rot may be limited to decorative timbers, while in others, it may have spread to structural elements or be accompanied by related issues such as woodworm or dry rot. These variables all impact the overall cost of repair.

    The most reliable way to understand the potential costs for remediation is to arrange for a professional survey. Our specialists will inspect your property, identify the source of moisture, assess the level of damage, and provide a detailed report with an itemised breakdown of the costs involved.


  • Is Wet Rot Covered by Insurance?

    Some policies exclude timber decay. We offer wet rot insurance to protect you from future risks.


  • How Long Does Wet Rot Treatment Take?

    Most wet rot treatment projects are completed within 1 to 3 working days. The timeframe will depend on the size of the affected area, the severity of the damage, and whether structural timbers need to be replaced. In most cases, you can remain in your property while the work is carried out. However, for major structural repairs, temporary relocation from certain rooms may be advised for safety and efficiency.


  • How Can I Prevent Wet Rot in the Future?

    • Keep the property well-ventilated
    • Maintain roofs and plumbing, whilst preventing all forms of moisture ingress.
    • Regularly check timber in high-moisture areas
    • For long-term peace of mind, seek expert guidance from a specialist. A professional inspection can help identify hidden risks and recommend tailored prevention strategies

Contact Your Local Wet Rot Specialists

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