The Difference Between Wet Rot & Dry Rot

 
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The Difference Between Wet Rot & Dry Rot


The best way to resolve your property care problems Is to start asking questions. We are contacted everyday by homeowners and landlords who are worried about the condition of their property.

“What’s the difference between dry rot and wet rot?”

This is one of the most popular questions that we receive. Both are wood destroying fungi and there are certain tell-tale signs between the two. However, if you have spotted signs of rot or damp within your property, we would advise that you contact a member of your local Richardson and Starling team for advice. Our trained surveyors will be able to correctly identify a wet rot outbreak (Coniophora Puteana) as opposed to a dry rot outbreak (Serpula Lacrymans). 

It is important that you correctly identify which fungi is affecting your property. See below to find out more about these two problems. 

What are the Main Differences?

Wet rot and Dry rot are two different types of fungi. One of the main differences between wet rot and dry rot is that wet rot needs a higher moisture content to grow. Wet rot fungus likes to grow on timber with a high moisture content of around 50% and above while for dry rot to grow it will germinate at a lower timber moisture content of around 20% to 30%.

There are many different types of Wet rot however there is only one Dry rot fungi. Telling the difference between dry rot and wet rot is the first step to successful eradication of the outbreak. 
Floor damaged by wet rot
Identifying Wet Rot 
  • In some cases, mycelium strands may appear on the timber
  • Fungus affected timber shrinks and causes cracking to the timber 
  • Timber is likely to feel soft and spongy to the touch  
  • Discolouration of timber is often present
  • Wet rot stays to the damp area and does not spread
  • Paint finish can appear damaged, highlighting the cracked timber below
  • Damp musty smell
Identifying Dry Rot 
  • A white mycelium growth like cotton wool appears when fresh
  • The mycelium can have a lemon-yellowish tinge
  • The mycelium turns to grey when older
  • The timber will crumble when badly affected with dry rot
  • Damp musty smell
  • Red spore dust from the fruiting body is evident in rooms.
  • Paint finish can appear damaged, highlighting the cracked timber below
Dry Rot repair works
  • The fungus leaves deep cuboidal cracking running across and along the grain
  • Dry rot mycelium will grow along and through walls to find more timber to colonise and can spread right through a property
  • Fruiting bodies grow when the rot is well established (mushroom like appearance)
Property rot attacks are extremely complex and they can be hard to tackle if you are unsure of their identity. Each property problem is unique and requires its own specific plan to eradicate the fungal attack.

How Wet Rot and Dry Rot are different?

Property repair experts will tell you that dry rot is incredibly serious and it should always be resolved as soon as possible. It is a destructive form of decay in a building as it spreads away from the source of damp and destroys timber and other property fabric. 
Dry rot spores on the ceiling
As for wet rot fungus, this type of rot occurs more frequently but is more localised. The decay usually affects timber where it becomes damp. However, do not underestimate wet rot. If left untreated wet rot can cause major structural problems.

Dry Rot is only caused by the fungi Serpula Lacrymans and it is the most serious form of fungal decay in buildings. It can spread through a complete building and destroy the fabric of the property. As we have mentioned dry rot can affect any unprotected timber which becomes damp with a moisture content of above 20% which can be achieved quite easily in a property.
Wet rot and Dry Rot may appear as a result of defective plumbing or penetrating damp caused by defective render, guttering and downpipes. Both Wet and Dry rot can cause significant damage before a homeowner is aware that there is even a problem. It can germinate behind wall fabrics and below floors.

Where Does Wet Rot Grow?

Wet rot is a fungus infestation which thrives in damp conditions. Any unprotected timber in your property from your roof to the ground floor which becomes damp is at risk of fungal attack. There are many types of wet rot fungi and the infestation should be treated as soon as possible as it can structurally deteriorate timbers in your property or home.
Wet rot can often lead to major structural damage if it is left to grow unchecked as it can weaken timber. Fortunately, wet rot does not spread through masonry and the growth of wet rot will cease when the moisture is removed.

Several factors can lead to wet rot including damp sources from rising damp, leaking roofs, gutters and problems with defective stone pointing or render can all cause the damp conditions in your property to germinate the wet rot fungi. When looking for damp, you should start off with these areas.
Timber damaged by wet rot

Where Does Dry Rot Grow?

Any unprotected timber in your property from your roof to the ground floor which becomes damp is at risk of Dry Rot attack. If you think that you have spotted the presence of dry rot, then you should investigate the affected area. Before you start looking for dry rot, it is worth knowing that is it can appear in an old building or a modern structure. Dry rot is caused by dampness that germinates the dry rot fungus spore on the timber. This means that it can appear almost anywhere. This type of rot is often caused by leaking roofs, penetrating damp due to defective gutters and masonry to plumbing leaks right inside the house.

It is common for dry rot to thrive in attics, underfloor areas or behind wall fabrics that have poor ventilation.

How to Treat Dry Rot

Dry rot needs to be treated by specialists. Our team will help you to locate and eliminate the presence of dry rot within your property. The affected fabric and timber requires to be removed and replaced and the masonry treated with a biocide to eradicate the Dry Rot growth. In terms of treating dry rot the following will happen:
Richardson & Starling surveyors are surveying a property
1. Richardson & Starling specialists will identify the source of moisture which is maintaining the rot.
2. We will highlight the defects such as overflowing or damaged gutters, defective render or blocked air bricks that is causing the problem and requires repair.
3. Our team will strip out the affected area including decayed wood, damaged linings, panelling, skirting’s, ceilings wall fabric and flooring. 
4. The structural timbers will be repaired, protecting them from damp masonry
5. The affected area will be treated with the appropriate fungicide to form a protective chemical treatment.
6. Ensure the full extent of the rot attack has been dealt with prior to reinstatement of the wall, floor and ceiling fabric.
There are several different products available for dry rot treatment to timber. There are products that enter the timber itself as well as ones designed for coating the timber surface. Fungicidal gel can be painted onto the timber surface, and comes in different concentrations depending on whether you want to prevent Dry Rot or treat it. To find out more about dry rot treatment, read our full guide. 

How to Treat Wet Rot

As wet rot is different from dry rot it is cured differently. The following stages will happen when we are eradicating wet rot:
  1. Richardson & Starling specialists will identify the source of moisture which is maintaining the rot.
  2. We will highlight the defects such as overflowing or damaged gutters, defective render or blocked air bricks that is causing the problem and requires repair.
  3. Strip out the full extent of the affected area.
  4. Repair or supplement any weakened structural timber protecting new timber from the damp masonry.
  5. Once that has been done, we will then apply fungicidal treatment to the remaining adjacent timbers that may be at risk
  6. Ensure the full extent of the rot attack has been dealt with prior to reinstatement of the wall, floor and ceiling fabric.
Timber affected by wet rot
The first and most crucial part of wet or dry rot treatment is to identify and cut off the source of moisture. 

In some cases, internal issues such as leaking radiators can encourage wet rot problems. If you suspect that there is a wet rot problem within your property, call a member of our local wet rot specialist team today.

Get in Touch with Richardson & Starling

Did you know that we give a 30-year guarantee for treatment of Dry and Wet rot, Rising Damp and Woodworm treatment? We are confident that we will be able to help you identify and treat the rot problem affecting your property. 

Our team of surveyors and technicians are always on the look-out for cutting edge industry-led initiatives to ensure that we can offer you the very best solutions to eradicate your property damp or rot problems. 

If you suspect that you have a property problem, get in touch with your local Richardson and Starling wet rot and dry rot eradication specialists. We will be happy to help you with accurate diagnosis and cost-effective repair plans to solve your property problem. We have branches throughout Scotland and North of England who are focused on property preservation. 

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