For more information call
01403 210204

Timber Treatment Tips!

Although a very versatile and visually appealing construction material, timber is vulnerable to multiple different types of degradation as a result of its environment. The problems timber can suffer from include rot, woodworm infestation, warping and surface biological growth.

The treatments required to fix or prevent these issues vary not only depending on what the problem is but also whether it is in an indoor or outdoor environment. This handy guide will help direct you towards the correct treatment methods for most timber problems.

Call or submit an enquiry if you need help solving any timber treatment problems or would like to find a qualified surveyor.

A Cure for All Ills

It should be noted that for almost all of the issues below the best way to ensure they do not occur is to provide a dry and warm environment for the timber in question. The suggestions given in this article make the assumption that efforts have been made by the property owner to provide such an environment, either before or after the discovery of any problems.

To Biocide or Not to Biocide?

Biocidal timber treatments are commonly applied to timber to prevent rot or mould problems from occurring. This is not always the best way to deal with such problems. Increasing regulation on the use of biocides in outdoor environments means that modern silicone-based treatments can often provide a more convenient all-encompassing solution.


If it is subjected to a damp environment, wood is at risk of being affected by rot infestation. This can be very detrimental because rot can weaken wooden structures and cause significant damage. In some cases, such as with floor joists and floorboards or structural timbers, this damage can be a significant danger to building occupants.

Dry rot on a wooden board

Preventative, Not Curative

A common misconception about treating rot on wood is that the treatments available will be able to eradicate existing infestations. This is not the case. Even professional-use biocidal treatments are classified as preventative under the European Biocidal Products Regulation and will not ‘cure’ previously infested wood. Any rotten wood will need to be removed and replaced. Any treatment carried out thereafter is done to prevent future infestations.

Indoor Environments

In indoor environments, it is essential to determine if you are dealing with wet rot or the more serious dry rot. All suspected rot infestations should also be investigated by a professional to prevent misdiagnosis.

Wet rot indoors is primarily dealt with by removing infested wood and ensuring a dry environment. Treating the surrounding timber with Soluguard Woodworm & Rot Treatment should be considered a secondary preventative action.

Dry rot should always be treated by a professional who has a deep understanding of the biology of dry rot and access to the appropriate treatment materials such as the Probor Wood Preservative range, which is only available to professional users.


Dry rot can cause widespread structural damage. We recommend that a professional timber treatment company is called in to carry out a survey if dry rot is suspected. If you suspect dry rot, please contact our technical department on 01403 210204 or submit an enquiry and we will be happy to arrange for an experienced timber treatment company to contact you.

Outdoor Environments

For exterior timbers, whenever possible, preventing any rot infestation from occurring in the first place is the best course of action.

For wood in typically exposed environments, you can minimise the likelihood of rot by applying a coat of Roxil Wood Protection Cream. The colourless silicone-based coating will soak into the wood and protect it from moisture ingress for 10+ years without staining it. By keeping the wood dry, it will be more difficult for rot fungal spores to take root in the wood.

If the external timber structure to be treated is at high-risk of rot infestation due to being in a shaded or very moist area, a coat of Soluguard Woodworm & Rot Treatment can be applied to the timber by brush before carrying out the Roxil Wood Protection Cream application. Soluguard Woodworm & Rot Treatment is fully compatible for use as an undercoat to Roxil Wood Protection Cream.


Unlike when treating rot, woodworm infestations can be treated both curatively and preventatively. Any infestation will need to be identified by a surveyor, as certain types of woodworm must be treated by professionals, but most active infestations can be treated without the need to replace or remove the affected timber. It is also worth noting that woodworm holes may just be a sign of a previous infestation that is no longer active. For a more detailed look at the different types of woodworm, refer to our Woodworm Identification & Treatment guidebook.

Damage caused to wood by Deathwatch Beetles

Indoor Environments

Woodworm infestations are normally noticed in indoor environments and the treatment for indoor infestations is almost exclusively done using biocidal liquids. Whether the infestation is currently active or a previous one, Soluguard Woodworm Treatment is the best method of treatment. It will kill any live beetle larvae and prevent the occurrence of future infestation for at least five years. For some less common types of woodworm, treatment must be carried out by professionals using specialist materials.

Outdoor Environments

In outdoor environments, woodworm is likely to be found in very damp environments. In the wild, they typically would be found attacking damp rotten dead wood on forest floors. Dry wood is undesirable to woodworm. An application of Roxil Wood Protection Cream will protect exterior timber from moisture ingress, drastically reducing the chances of a woodworm infestation occurring.

If external timber has already been infested with woodworm and the infestation is still active (or suspected to still be active) then an application of Soluguard Woodworm & Rot Treatment should be carried out as an undercoat before the application of Roxil Wood Protection Cream. The Soluguard Woodworm & Rot Treatment will kill any woodworm already present in the wood and the Roxil Wood Protection Cream will help to keep the wood dry and further discourage future infestations.

Warping & Cracking

As wood gets wet, it expands. This expansion can cause problems in wooden structures that can result in both unsightly warping and more serious issues such as cracking or splitting at joints. The more times wood goes through a wetting and drying cycle, the worse the problem will become. Splits and cracks, in particular, can be an access point for mould or rot spores to bypass any biocidal surface treatments.

Garage with rustic warped wooden shingle gable end wall

Warping should not be a common occurrence in indoor environments. If warping does occur inside a particular building, it is a sign of an unusually humid or damp environment. Efforts should be made to isolate timber from any sources of dampness and the correct heating and ventilation facilities put in place.

Outdoor wooden structures are far more likely to be affected by warping due to exposure to the elements. An application of Roxil Wood Protection Cream will stop moisture ingress and improve dimensional stability, reducing the likelihood of warping, cracking or splitting. Roxil Wood Protection Cream can also be used to treat wood that is going to be embedded in the ground.

Surface Mould & Algae Growth

Even well maintained wooden surfaces are likely to get dirty over time. If there has been surface condensation or pooling water then you may get some surface mould or algae growth, both indoors and outdoors. This form of biological growth is largely an aesthetic consideration. To remove dirt, mould and algae it is best to use an appropriate biocidal cleaner.

Roxil 100 Wood & Patio Cleaner being spray applied to a wooden fence panel

For indoor wooden surfaces, it is recommended to use Dryzone 100 Mould Remover to remove mould and dirt. On outdoor wooden surfaces, it is recommended to use Roxil 100 Wood & Patio Cleaner. Both of these cleaners are biocidal but bleach-free, meaning that they will kill mould and minimise regrowth. Both Dryzone 100 Mould Remover and Roxil 100 Wood & Patio Cleaner are non-destructive. Some competing wood cleaners work by stripping away the top layer of the wood, causing discolouration and making regrowth more likely.

Additionally, for outdoor structures, an application of Roxil Wood Protection Cream will keep the surface of wood dry and significantly reduce mould growth. Any surface growth that does occur can be easily cleaned away using Roxil 100 or Dryzone 100 cleaners.

For more information call
01403 210204