Evidence of dry rot fungi forming

Help And Advice On How To Treat Dry Rot

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What is dry rot?
How dry rot affects your property?
What causes dry rot?
How to identify dry rot?
How to treat dry rot?
History of dry rot
Get in touch with our dry rot treatment specialists


What is Dry Rot?

Dry rot is a term used to describe a very specific and unique type of wood rot (Serpula Lacrymans). However, despite its common name, it will generally only attack damp timber.

Initiation of attack is by either a minute dry rot spore or cross-contamination from already infected material, eg, wood, masonry. Depleting wood of such components leaves it in a brown brittle state which is unsafe in any property.

Dry rot is a serious problem across properties in the United Kingdom. For an infection to be initiated there needs to be a spore (or some growth that is viable already present), oxygen, a suitable temperature, a susceptible food source and water, all of which are to be found in buildings.

Dry Rot Specialist CTA

How Dry Rot Affects Your Property

Dry rot can affect all kinds of timber from old or new domestic and commercial properties. This form of timber decay is increasingly a widespread concern for homeowners across the United Kingdom. If your dry rot problem isn’t treated promptly then dry rot can become a danger to you and your home.

If you are having problems with dry rot then the best solution is to book a dry rot survey through Timberwise. We have over 50 years’ experience in providing treatments for dry rot and you can be assured that with our specialist surveyors your property is in safe hands.

Sometimes, finding out that there is actually a dry rot problem is the hardest part of the dry rot treatment process. Once dry rot has been identified within the property help is at hand, Timberwise will be able to alleviate any stress or concern you may have.

What Causes Dry Rot?

Dry Rot in timber
Dry rot occurs where the timber is damp and the affecting damp has a moisture content that is in excess of 20%. There are many reasons why the timber in your property can become damp (such as penetrating dampness).

The other vital ingredient to causing a dry rot outbreak is dry rot spores which are omnipresent, meaning they surround us every day, unseen by the human eye.

By themselves these spores are harmless; however, when the spores come into contact with wet timber, they can germinate, reducing the wood to an unsound structural state.

The fine fungal thread (hypha) digests the cellulose and hemicellulose fraction of woodturning the wood brown and ultimately reducing the timber to a dry and crumbly state. Dry rot does not attack the structural lignin of the wood.

All damp problems that can affect your property such as rising damp and penetrating damp can affect if dry rot may be present.

Before any treatment can be made to treat dry rot the damp issues must be solved first. The reason for this is that the dry rot treatments are will become ineffective if the timber is damp again the dry rot is likely to colonise again.

To learn more about the causes of dry rot, please visit our what causes dry rot page.

How To Identify Dry Rot

Dry rot is often confused with wet rot however, there are differences between wet and dry rot. The biggest difference is the amount of moisture that is needed for both wood rot to germinate.

The characteristics of dry rot depend on its stage of development. The first evidence of the existence of an outbreak of dry rot is often the sudden appearance of a fruiting body (sporophore), or the shrinking/distortion of timbers.

This latter feature can be quite dramatic and sudden, the change from dimensional stability to the instability of the wood visually taking place relatively suddenly.

Dry rot flourishes in damp inadequately ventilated conditions, so it will most often be found in enclosed hard-to-reach areas such as under floorboards, behind skirting boards and door frames/casings.

Unlike many other wood destroying fungi dry rot can readily grow over and through porous masonry provided that there is a nutritional source (wood) from which it can spread; this ability allows the spread of the fungus from one area to another.

As these areas are often unseen, it is often the case that the wood rot has already progressed into an advanced state when detected; therefore, it is essential to identify the issue at its earliest opportunity. To learn more about identifying dry rot, please visit our what are the signs of dry rot page.

How to Treat Dry Rot

Affected Timber

A dry rot survey must be carried out by a qualified surveyor to ensure the right treatment is applied to the dry rot infected area. The surveyor will provide a thorough inspection to see if there may be any other types of rot or any possibility of damp.

The surveyor will provide the best solutions to your property with a detailed report outlining the findings of the survey.

To treat dry rot, our technicians and surveyors will:


      1. Gain Access to Repair Infected Wood- Our trained technicians will remove any infected wood as well as any wall plaster that will allow us to directly access the area under attack.
      2. Dry Rot Treatment Process- Dry rot treatment is used to treat the damaged timber caused by the wood rotting fungi by eradicating the sources of moisture and promoting rapid drying from the area. Controlling the moisture will enable the structure to dry out and prevent dry rot spores from germinating. Some areas of the outbreak may also need to be treated with masonry biocide and fungicide pastes in order to prevent further attacks of wood rotting fungi and/or wood boring insects.
      3. Replace Timbers- Having treated the timber, one of the final procedures we undertake is to remove infected material, replace/repair and consider engineering methods to isolate structural timbers.
      4. Improve Underfloor Ventilation- One of the preventative methods that we use to get rid of dry rot is to improve the ventilation within a property. Airflow will also help to get rid of the outbreak by aiding the drying process. It may also be necessary to install a mechanical ventilation solution to remove moisture-laden air from the property. By improving airflow, we are removing one of the contributing causes of dry rot.
      5. Prevent any possibility of an attack reoccurring- Finally, our surveyors will advise what additional steps (if any) are required to safeguard the property from further dry rot outbreaks.

As members of the PCA, our qualified technicians and surveyors have a wealth of dry rot knowledge at their fingertips. Our qualified experts will conduct an extensive dry rot survey and make appropriate recommendations to treat the infected area. Our surveyors will also advise on how to prevent any dry rot attack from occurring again.

A recent example of an outbreak of true dry rot was found by our experts in a church in Liverpool. The outbreak was discovered in the rafters and a load-bearing truss timber within the timber structure at ceiling level.

On this occasion, our dry rot specialist recommended a mass irrigation sterilisation treatment to the walls in excess of 150mm thick including a surface application to the exposed masonry in the vicinity.

In areas where there were severe fungal decay sections of the timbers were removed and replaced with closely matched timbers that were pre-treated with a fungicidal paste and damp proof membrane.

The History of Dry Rot

Mycelium Growth

Originally known as Merulius Lacrymans(meaning tears of the Blackbird, as it was thought initially that the fungus and fungi were spread by blackbirds) the fungal decay we now know as Dry Rot can be dated back to the 18th century. However, the history of its presence in the United Kingdom still remains obscure.

Dry rot is thought to have been transported to British shores by ships from Europe carrying infected timbers; in some cases, cargoes were largely destroyed in the ships before they reached the port.

Get In Touch To Our Dry Rot Treatment Specialists

Timberwise fully appreciates it is imperative that all areas of dampness are identified as timbers within these areas will be at risk to rot developing if such timbers are not fully protected from either the moisture or the rot itself.

Dry Rot Specialist CTA

We are also aware that where dampness is identified and where there may be hidden timbers these may have already rotted.

However, previously decayed wood where rot is now dead may sometimes be found in areas that have dried out and if structurally sound or of no importance these may be left provided they can be maintained dry.

If you are concerned about the possibility of a dry rot outbreak in your property, do not hesitate to give our team of dry rot specialists based across England, Wales and Scotland a call on 0800 288 8660, or alternatively, you can request a survey online.

Having a dry rot survey through Timberwise will be able to identify the full extent of the problem and determine whether further dry rot treatments are necessary.