Almost all structures, old or new, use timber as a building material. People have been building houses for thousands of years using timber. One of the reasons why is because it’s readily available and is also renewable as long as new trees are planted to replace those that are harvested.

But despite all of its advantages, one issue with using timber remains — it is susceptible to fungal decay. Wet rot is one of the leading threats to structural timber. If your property is suffering from damp problems, it is highly possible that the issue will escalate to wet rot.

Just like with damp problems, identifying the issue as early as possible is critical. If left untreated, wet rot can cause wood to lose its strength, putting your home at risk of structural dangers.

What is wet rot?

Wet rot is a general term for several fungal species that causes wood to decay. The most common of which is cellar fungus (Coniophora puteana) that thrives in and affects very damp timber.

It occurs when there is excessive moisture in timber over long periods of time. Where timber has become and remains wet, wet rot is most likely to follow. The moisture may come from different sources —  most of which are unknown to you.

Though it occurs more frequently than dry rot, wet rot is less of a danger. Typically, it only causes decay on the part of the timber that has become wet because of moisture. However, work should still be done quickly as soon as you discover infected parts of the house.

Wet rot vs dry rot

Discovering which parts of the house are infected with wood-decaying fungi is the first step to eliminating wet rot. The next is treatment. However, it’s important that you know whether or not the culprit is wet rot or dry rot, because treatment is different for each of them.

The problem here is that dry rot and wet rot have a lot of similarities that might be confusing unless you hire a professional. After all, outbreaks of dry rot and wet rot start in similar ways. However, there are some notable differences between the two:

  • Unlike wet rot which can be caused by several species of fungus, dry rot is only caused by serpula lacrymans. Do note, that dry rot is the most serious form of fungal decay.
  • Dry rot can spread onto and destroy much of the timber. It can also spread out to adjacent stone or brick walls. Wet rot, on the other hand, is typically confined to the area of dampness.
  • Signs of dry rot include a distinct mushroom smell, white fungal growth with yellow and lilac tinges, and deep cracks in the wood.
  • Telltale signs of wet rot are distortion, discolouration, softness and cracking of the wood. Timber will also lose its strength while appearing somewhat ‘spongy’. There may also be a damp musty smell present, and fungal growth can sometimes be visible.
  • Wet rot grows on porous surfaces where there is moisture content of at least 50%. Dry rot requires only around 20% moisture content.

Causes of wet rot

There are areas in the house that are more likely to suffer from wet rot infestation compared to others. If you suspect that your home has wet rot, it’s advisable to check the following areas.

Windows and door frames are favourite spots for wet rot since water this is a prime place for water to collect.

Timber in the roof is also at risk especially if there is roof damage which allows rainwater to run onto the timber.

Walls and flooring suffering from damp may have been infected by wet rot. Don’t let a beautiful paint job fool you. If in doubt, push a thin blade or screwdriver into the wooden frames. If it goes in up to the handle, there’s probably wet rot in the wood, but if it doesn’t, there shouldn’t be a problem.

Learn about damp problems since this is the leading cause if wet rot. The smallest leaks from a water supply or drain, when unnoticed, can lead to dampness which may result in wet rot.

The risks

The biggest threat that wet rot has is that it makes your home a dangerous place when left untreated. This is true even if wet rot is less destructive compared dry rot. Wet rot can also significantly affect the result of a building survey. If there is a wet rot problem, it’s very likely that your mortgage lender will not agree to lend unless inspection from a wet rot specialist is conducted.

Healthwise, you’d be glad to know that wet rot doesn’t pose any major concerns. Still, keep in mind that the fungi spores may trigger asthma in children. The spores can also further aggravate the conditions of people with existing respiratory illnesses.

How to deal with wet rot

Since wet rot is primarily because of excessive moisture, rectifying the source of dampness is the key. Repairing or replacing the damaged part is not sufficient if the conditions that caused it are not corrected. The last thing you want is to eliminate wet rot only to have it return.

You can fix the problem using the DIY steps below.

  1. Make sure that the source of damp or water is repaired. The moisture should be at the safe level which is below 20%.
  2. Remove the weakened or affected wood. Fairly small areas that are affected can be cut away and filled with wood filler.
  3. Apply fungicidal treatment to the remaining timber including the neighbouring areas around it.
  4. Replace with new timber that is treated with preservative if applying wood filler is no longer possible.
  5. After the repair work is done, make sure that it’s dried out, and again, insulate your home it’s extremely important to eliminate the sources of excess moisture.

Finally, seek a professional’s help when needed especially if you’re unsure whether what you have is dry or wet rot. Applying the wrong treatment may lead to further problems which you don’t want to happen.