Dry Rot or Wet Rot – Which is Worse?

Dry rot and wet rot are two different types of condition that can lead to serious problems in properties, but do you know which one is worse than the other?

What is Dry Rot?

Dry rot is a type of wood rot that can be very difficult to spot, whilst causing some serious damage. The reason it is difficult to notice is that dry rot typically forms and spreads in places that are hidden and hard to see. Dry rot fungus grows under floorboards, behind plaster, on the roof, and other out-of-sight areas. This is why it is extremely important to be able to spot the subtle symptoms of dry rot. On rarer occasions, the symptoms can be easily visible.

This wood condition is caused by the fungus Serpula Lacrymans, which causes devastating damage in a very short timeframe. It spreads fast, and it affects many different types of wood throughout the building.

What is Wet Rot?

Unlike dry rot, wet rot is theoretically much easier to notice. This is a type of wood condition which occurs in places with high moisture levels. Wood affected by wet rot starts to change colour, becoming lighter or darker depending on the type. It also becomes soft and can easily break, making it a huge structure risk. Wood hit by wet rot will eventually dry out, but the damage remains. It will be much weaker, and it starts to disintegrate easily even when touched by hand. Compared to dry rot, wet rot occurs more frequently, but it can’t do as much damage. Wet rot doesn’t spread as easy and as fast, and it is generally easier to treat and remove.

Is Dry Rot Worse than Wet Rot?

Dry rot is commonly considered to be more dangerous than wet rot — thanks to its ability to spread faster and undetected –, and it also affects more types of wood. However, in terms of structural damage, wet rot can be right on par with dry rot. Wet rot can completely destroy an area of a building if the moisture level there has been above 20% for a long time.

What is the Difference between Wet Rot and Dry Rot?

Wet rot and dry rot are generally very different and easy to differentiate, however, there are some key similarities between them. Not being able to tell the differences and similarities can often leave you confused and prevent you from taking appropriate action. This is why it’s best to have a wood rot expert carry out an inspection of your home the moment you suspect anything. A specialist can properly identify the issues and recommend appropriate action.

Wet rot and dry rot are caused by two separate types of fungi. The main cause of both is moisture and damp. Wet rot appears in a damp area where the moisture has been high for a long time. Dry rot forms in more inconspicuous places around the building, where damp and moisture are not as high but still present.

Because they are caused by separate types of fungi, the ways wet rot and dry rot spread are different. Wet rot can’t travel through dry wood as dry rot can, and it is generally easier to spot, contain and treat. Dry rot can spread through adjacent masonry and infect healthy wood quickly and easily. This is due to the different degree of mycelium caused by the two types of fungi. Wet rot is caused by Coniophora Puteana, a fungus that contains mycelia that is black/brown in colour (when found under linoleum, it can also be white). Its fruiting bodies are white/grey. Coniophora Puteana is the most common type of fungus causing wet rot, but not the only one. There are more than 20 variations of it, but this one is the most common. Both wet and dry rot can cause significant damage to your home. They require completely different treatments, and if caught in their early stages, they can be easily contained. However, if you fail to take action in time, you can end up with a very serious and costly structural damage to your home. This is why it’s crucial to seek professional diagnosis and treatment. If you notice signs of wet or dry rot call Southern Damp Proofing on 020 7971 1329 immediately and request an inspection.


Frequently Asked Questions

Is Wet Rot more Common than Dry Rot?
Wet rot is generally more common than dry rot. It has two main varieties – Brown or White Rot Fungus. It appears as a result of building defects or long term Rising Damp. Wood that is built into walls, or in contact with other damp masonry is most vulnerable to wet rot.
How Does Rot Start Spreading?
The most likely culprit is damp. Damp places with insufficient air ventilation are the most likely to have problems with wood rot.
How to Spot Dry Rot Issues?
Being able to spot dry rot is crucial since it spreads very fast and causes grave damage. The signs you should look out for include musty, damp smell, and flaky wood that has a brownish colour, plus it’s very dry to the touch. There can also be white or grey strands growing out of the wood. The last and most serious symptom is the appearance of rusty dust around the affected wood.
How to Spot Wet Rot Issues?
Some of the symptoms of wet rot may be similar to dry rot. The musty, damp smell is a common sign. You may notice the floor to be springy when you walk over it, as well as the presence of woodlice or silverfish.
How to Best Treat Rot?
The first step is to accurately locate the source of moisture and damp, regardless of the type of rot you are dealing with. Once the source has been treated, further repairs can proceed. If you have the affected areas treated without eliminating the source, the problems will only return. Unfortunately, building wood quality is not what it used to be. It can’t withstand moisture like in the past and it tends to break down faster and easier.