Wet rot under floor boards

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Wet rot

Wet rot is a fairly common form of timber decay caused by fungal growth spawned by damp conditions and wood with high moisture content. While not as severe a problem as dry rot, unfortunately, it still has the potential to seriously impact the structural integrity of your property if left untreated.

The specialist surveyors at Peter Cox have been identifying and treating wet rot in properties all across the UK for decades. If you are concerned that you might have identified some of the signs in your home then read on for more information or book a wet rot survey today using the button below.

What is wet rot?

There are a variety of different types of wet rot and it can grow anywhere in the property, however, The most common species is Cellar Fungus (Coniophora Puteana). In simple terms, it is a form of fungal decay that is caused by the combination of water ingress, damp timber and a lack of ventilation.

It requires a constant source of water to grow, thriving in conditions of 30-60% moisture. This is usually caused by defects in plumbing, external guttering or pipework that create leaks. Wet rot cannot travel through masonry, and this can sometimes cause wet rot to go undetected for an extended period of time if it is blocked into a non-visible area. A great way to prevent wet rot is by conducting routine checks of your property’s water management systems and pipes. This property maintenance will help to make sure wet rot doesn’t have the opportunity to germinate and grow undiscovered for any length of time.

What is the difference between wet rot and dry rot?

Technically speaking there is a variety of wet rot fungi including Coniophora fungus, Fibroporia vaillantii (mine fungus) and Phellinus spp. Dry rot on the other hand is only caused by the Serpula lacrymans fungus.

The key difference, however, is that dry rot is capable of spreading throughout the building, whereas wet rot remains localised to the source of moisture that allowed it to grow in the first place.

This, unfortunately, means that dry rot is usually a far more serious problem and dry rot treatment is required as early as possible to stop its ability to spread and germinate across other surfaces.

Unlike dry rot, wet rot requires a much higher level of moisture before spores will begin to germinate. However, once the source of moisture has been removed, wet rot will stop growing and will no longer have the ability to spread. This makes wet rot a lot easier to treat. You can read more about the differences between wet rot and dry rot on our dedicated page.

Although wet rot is not as severe as dry rot it can still cause serious structural damage. If the signs of rot appear in your home, then we always recommend getting in touch with a qualified rot specialist to inspect your property. While they are both a form of timber destroying wood rot fungi, if you know what to look for you can see that these types of wood rot develop differently.

How to Identify wet rot

To help you identify whether or not you have a wet rot problem, we have put together some pictures of wet rot fungus infestations so you can understand what it looks like and provided a guide to outline and describe the tell tale signs of wet rot. If you spot any of the following in your property then you will want to consider contacting a specialist damp and rot treatment team.


What are the signs of wet rot?

wet rot fungus under floorboard

Wet rot fungus

Wet rot fungus grows in stages. Early in its life cycle it will develop in strands called hypha that look a bit like spider silk forming into fern-shaped patterns. Depending on the specific genus of wet rot growing the colour will vary from brown rot to white rot.

These strands will later develop a white skin or coating and eventually a series of small fruiting bodies that look like tiny “off-white” mushrooms. This is known as Mycelium and is often accompanied by a musty smell.

Timber darkens or lightens in colour

Wet rot can cause timber to change colour, darker or lighter depending on environmental factors, and this will coincide with a breaking down of the timber which makes it soft and spongy to touch.

Localised decay

Due to the high level of moisture and damp, timber can begin to break down and create localised decay. Timber features such as skirting boards, window sills and floorboards often show physical signs of decay caused by wet rot such as paintwork on timber becoming damaged or showing signs of fungus appearing.

To assess if wet rot has affected the timber, take a flat-edged knife and insert it into the affected timber. If the knife can go in up to the handle, there is likely an issue with rot in the timber.

Pictures showing the signs of wet rot

Where does wet rot grow?

A challenge associated with identifying wet rot is that it often develops in hard-to-spot areas of a property due to unseen water ingress. As a result, wet rot can be commonly found in damp basements, under floorboards, behind skirting boards and underneath leaking fixtures and fittings such as baths, toilets and washing machines.

How to treat wet rot

Because wet rot occurs as a result of water ingress, it is imperative to find the source of the moisture and eliminate it. Wet rot will continue to grow and manifest if the moisture source remains.

Once the source of moisture has been identified and fixed appropriately, treatment can begin to repair the damaged timber. Wet rot treatment will vary depending on the extent of the timber damage and may require replacing any defective timber. Our timber repair specialists will try to retain healthy structural and decorative timber whenever possible. Any timber retained will be treated with fungicidal treatment to prevent further infections.

Also, for complete peace of mind for our customers, Peter Cox provide a 20-year guarantee on all of our wet rot treatments meaning that you can rest assured that your home will remain free from wet rot.

Our wet rot treatment reviews

We are justifiably proud of our reputation as the leaders in the property care industry, take a look at what customers have been saying about our wet rot treatment services.

Contact the wet rot specialists

If you suspect you have an issue with rot in your property, then do not hesitate to contact us. For expert advice or to arrange a professional survey with one of our surveyors, contact your local Peter Cox branch on 0800 633 5712 to speak to one of our experts.

Alternatively, the button below will take you to our online booking form.

Author: Steve Jameson CSRT CSSW

Steve is our National Operations Manager and there are few people in the industry with more experience treating wet rot. During his 30 years in the business, Steve has built a reputation as one of the nation's most experienced professionals in the field of rot and timber decay.

Next Steps

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