Timber is a common material in housebuilding in the UK, but because of its nature, it can be more susceptible to damage than other materials used in houses.
Berwyn Evans, UK Product Manager at Rentokil Property Care comments: “Timber has been used in the UK housebuilding industry for thousands of years, and hundreds of thousands of properties around Britain, whether newbuild, old or historic, rely on timber frames for their structural integrity.
“However, each year countless homeowners across the UK discover damage or decay to their homes through natural causes, in the form of wood rotting fungi.”
Berwyn talks us through how to care for your timber-framed home and how to spot signs of damage.
Rot or not?
“One of the most common causes of structural damage to timber is wood rot – a form of decay which leads to the breakdown of wood. This is due to fungal decay, which is caused by two different types of rot: brown rot or white rot,” he explains.
“While all forms of white rot are commonly known as ‘wet rot’, true dry rot is the best known brown rot, even though other types of brown rot are considered to be wet rot.”
Berwyn goes on to explain that rot starts when naturally occurring spores in the atmosphere land on damp timbers within the building. Once they settle on the timber, and provided all environmental conditions are correct, they germinate and produce fine strands of fungal growth called hyphae, in a similar way to the formation of bread mould.
Damage occurs when hyphae grow and join together to form a mass of mycelium. This grows into and across the damp wood, using enzymes to break down the wood structure. Other wooden features in homes including roof joists, window frames, floorboards, skirting boards and stairs can also be affected by wood rot.
Which kind of rot do I have?
Berwyn explains: “Wet rot requires a higher moisture content than true dry rot, and is often caused by continuous sources of damp, such as rising damp, poor sub-floor ventilation, lack (or failure) of a damp proof course, defective plumbing, leaking gutters, or a defective roof. It leads to distortion, discolouration, and cracking of affected timbers. The wood will lose strength, become soft to the touch, and may give off a damp musty smell. In some cases, visible fungal growths may occur. In most wet rots, the wood will become fibrous and pale in colour.
“Contrary to its common name, true dry rot does require moisture to be present, and usually begins on damp, poorly ventilated timber with less moisture than the amount required by wet rot. Nonetheless, it can lead to extreme decay and can grow through masonry in search of more timber, so it is essential that you identify signs of true dry rot before further damage is done.
“While the wood can remain more solid than in cases of wet rot, common signs of true dry rot include a distinct mushroom smell, cream fungal growths with yellow and lilac tinges, peeling paint and deep cracks within the wood. The fungus therefore requires swift action once identified.”
How do I prevent it?
Both forms require timber to have above 20% moisture content to grow, he says, so the best way to prevent them from forming is to limit the amount of moisture in the immediate vicinity.
Excess moisture can be caused by various types of damp so it’s best to ensure your property is well ventilated throughout the affected area. Where possible, open windows regularly or use ventilators or fans to regulate airflow. With all treatments, the primary control measure is to remove or isolate the moisture source, replace defective timbers and promote rapid drying.
Berwyn adds: “As the saying goes, prevention is better than cure, so be diligent in checking your property. If you’re unsure, contact a trained professional. Any delayed action can result in further structural damage to your property, as well as increasing the cost of any repair work that may need to be undertaken.”