The Ultimate Guide to Treating Wet Rot

The team at Croft Preservation have been dealing with wet rot for over three decades, so we know a thing or two about stopping it in its tracks. Read our guide below to find out everything you need to know about tackling wet rot, from identification to eradication.

What Is Wet Rot?

Wet rot is a broad term used to describe various types of fungal decay that break down timber in damp environments. Left untreated, wet rot can weaken wood to the point of collapse and threaten the structural integrity of your home.

There are two main types of wet rot: brown rot and white rot.

• Brown rot fungi attack cellulose in the wood, causing it to become dry, brittle, and crumbly.
• White rot fungi target both cellulose and lignin, leading to soft, spongy timber that often appears lighter in colour.

Both thrive in persistently damp environments – usually where moisture is present due to leaks, poor ventilation, or rising damp.

What Causes Wet Rot To Develop?

Wet rot fungi are airborne and naturally occurring, but they only activate in damp, poorly ventilated areas. The most common causes include:

• Leaking roofs or gutters: Moisture can soak into exposed timber if rainwater isn’t properly drained.
• Plumbing leaks: Dripping or burst pipes can saturate wooden structures.
• Condensation: Poor airflow in kitchens, bathrooms, and cellars can create the perfect conditions for rot.
• Rising damp: Moisture from the ground can travel up walls and into wooden skirting, floorboards, or joists.

If timber remains damp for extended periods, it becomes a prime target for wet rot.

What Does Wet Rot Look Like?

Spotting wet rot early can save time and costly repairs. Common signs include:

• Wood that looks darker than surrounding areas
• A soft, spongy or crumbly texture
• A damp, musty smell
• Visible fungal growth
• Bleaching or warping of the timber

If in doubt, it’s always worth getting a professional damp survey to confirm the presence of wet rot.

What’s the Difference Between Wet Rot and Dry Rot?

It’s easy to confuse wet rot and dry rot, but the two are distinct fungi with different behaviours and risks:

• Wet rot requires high moisture levels – typically over 50%. It remains local to the damp area.
• Dry rot can spread across materials like brick and plaster, even in lower humidity.
• Wet rot is usually easier to treat and contain.
• Dry rot spreads aggressively and can severely damage hidden timber over time.

In short, wet rot is serious, but dry rot is usually the bigger threat.

Can Wet Rot Develop Into Dry Rot?

No – wet rot and dry rot are caused by different fungal species. One does not turn into the other. However, if general damp issues are left unresolved, both types can exist in the same property over time.

How Can You Fix a Wet Rot Problem?

Treating wet rot involves a two-pronged approach: addressing the source of the moisture and treating the affected wood. Due to the complexity and potential dangers of the process, it’s usually best left to the professionals – they’ll have the tools and expertise to deal with the issue properly, even if the rot is extensive or hidden.

Here’s a breakdown of the steps they’ll take:

1. Survey and Diagnosis – A damp expert will use moisture metres and inspection tools to assess the extent of the rot and trace the cause – whether it’s a leak, condensation, or poor ventilation.
2. Eliminate the Moisture Source – The cause of the damp must be repaired — for example, fixing gutters, sealing leaks, or improving airflow.
3. Treat the Timber Severely rotted wood is cut out and replaced with new, treated timber. Salvageable wood is dried out and treated with a wet rot fungicide to kill remaining spores. A wood hardener may be applied to reinforce weakened timber.
4. Drying Out – Specialists may use fans or dehumidifiers to dry the affected area thoroughly before redecoration.

Effective Wet Rot Treatments in Dorset and Hampshire

Think you’ve got a wet rot problem? Don’t leave it to chance – Croft Preservation are your local specialists in damp and wet rot treatment across Dorset and Hampshire.

With over 30 years of experience, we’ve helped homeowners and landlords protect their properties from structural damage caused by wet rot. We offer expert diagnosis, fast treatment, and lasting protection — all delivered with a personal, reliable service.

Ready to stop wet rot in its tracks? Get a quote online or call us on 01202 737739 today!