The wood that is so often the backbone to most properties and forms the eye-catching, authentic features of houses up and down the country is under threat from fungi that can reduce it to dust.
Dry Rot and Wet Rot are two fungal presences that, if untreated, can cause untold damage to your property. However, they are two different problems; knowing the difference is essential.
Despite the name, both require dampness to thrive and can spread quickly, given the right conditions. The fungi both feast on the moisture in your timber and often exist out of sight, meaning by the time you identify the problem, it is usually well established.
We aim to equip you with the knowledge to protect your property from these fungi and preserve the charm you've created.
Dry Rot (Serpula Lacrymans)
The spores that cause Dry Rot, known as Serpula Lacrymans, are fuelled by moisture, and in the right conditions, they will grow quickly. The primary energy source for these dry rot spores is the cellulose in the wood. They attack the wood, consuming the nutrients, drying it out, and leaving it brittle and vulnerable.
Dry rot spores can and will spread rapidly in search of further fuel sources once they have exhausted their current timber home. They can spread across any porous surface, including masonry, to find fresh cellulose-rich wood.
Identifying Dry Rot
Identification can be challenging because Dry Rot is often concealed in a dark, damp corner of your property. However, the initial signs that you have a problem will be an unpleasant, musty smell. This odour will undoubtedly warrant further investigation. Be prepared for it to be beneath floorboards or behind walls. (in this case, you might want some professional help).
As the name suggests, the fungus is trying to suck up the moisture from the wood, which will leave it looking darker, brittle, cracked and potentially warped.
Once it has absorbed as much as it can from the wood, the fungus will leave a cotton-wool-like substance (known as Mycelium) around your wood. If you see this, then contact a professional as soon as possible.
Dry Rot needs moisture to grow, and in an attempt to find a new food source, it will start to produce reddish-brown, mushroom-like fruit to help the spores get airborne.
Dry Rot Treatment
While you can implement some preventative measures for Dry Rot, once the problem is confirmed, it is better to enlist the support of a specialist company to eradicate it completely.
The first step in treating Dry Rot is cutting off the source of the moisture. Dry Rot needs dampness to survive, which could result from rising damp, penetrating damp or condensation, so finding the source of the dampness is crucial.
Once the source has been identified and eradicated, it is essential to replace the affected wood.
The timber will no longer provide the structural solidity required as the fungus will have removed the cellulose, leaving it brittle and unstable.
Finally, once new timber is in place, the area must be treated with fungicidal products. As we mentioned, Dry Rot can move across masonry in the hunt for fresh wood, so the treatment will cover the whole area to ensure the spores are no longer active.
Wet Rot
Wet Rot is also a fungus, and there are various types, the most common being a cellar fungus known as Coniophora puteana.
Like Dry Rot, Wet Rot requires fuel to exist, and dampness provides the best conditions. While Dry Rot can exist in just 20% moisture, Wet Rot requires more moisture-laden conditions.
Wet Rot also attacks the fabric of the wood, breaking down the cellulose and lignin in the wood, leaving it moist and spongy in texture.
Identifying Wet Rot
Similar to Dry Rot, Wet Rot will often be hidden, devouring your wood in a dark, damp corner of your property. You will notice a musty smell, which is the dampness, rather than the Wet Rot fungi, which doesn't smell.
You will also see the typical signs of dampness around your decor, such as bubbling paintwork, peeling wallpaper, and discolouration.
Further investigation may reveal rotting in your wood. There will be obvious signs of timber decay, including a soft and spongy texture, and the Rot will appear brown or white.
There are two types of Wet Rot: Brown and White. The fungus's appearance will be different, indicating the two scenarios.
White Rot occurs when the fungus consumes the lignin, which bonds the wood together. This alters the wood's integrity, leaving it discoloured and spongy.
Brown Rot results from the fungus being unable to digest the lignin and feeding on the wood's cellulose and sugars, which is why the Rot is brown.
Wet Rot Treatment
The treatment for Wet Rot is similar to that of Dry Rot. Early identification can make a big difference. Wet Rot doesn't spread with the same voracity that Dry Rot can, so early identification can cut it off in its prime.
Identifying the source of dampness is critical, as it removes the primary condition for the growth of Wet Rot.
In some cases, if it has been identified early enough and is an isolated case, it might be possible to strip back the wood, treat it with a fungicide and strengthen it.
However, if Wet Rot has taken hold and is extensive, you will need to replace the wood and treat it with an appropriate resin, which should prevent further growth and the return of the fungus.
Prevention Tips for Both Types of Rot:
Keeping your wood dry is the number one preventative measure to stop Rot from taking hold in your property.
Ensure you have good ventilation around your property and fix any leaks or damaged rainwater goods as soon as possible.
Early inspection is essential, so check your property regularly to identify any potential sources of dampness and address them quickly.
When introducing any new timber to your property, ensure it is treated appropriately.
Most importantly, get the advice of a PCA member to advise. There are thousands of so-called experts, but PCA members will provide a specialist service.
About the Author
Dean Webster, is the Owner and Lead Surveyor of South East Timber and Damp.