Timber Rot in Building Surveys and Structural Surveys

When a Chartered Surveyor (member of the RICS) inspects a property for a home buyer, maybe a Building Survey (sometimes referred to as a Full Structural Survey) or a House Purchase Survey, one of the many possible defects the surveyor is on the hunt for is any signs of rot in timbers, for instance those that hold up the floors, staircases or roof.
Rot causes wood timbers to lose their structural integrity, that is their ability to carry the load placed upon them, when supporting the floor or roof.

There are two main types of timber rot, both caused by fungi that feed on the wood, thereby destroying it, but different in their treatment and veracity. These are called Wet Rot and Dry Rot.

Wet Rot and Dry Rot in London structural surveys

Perhaps counter-intuitively, Wet Rot is the easier to treat. It occurs when the timbers reach a high level of saturation, around 30%.

Dry Rot is the more virulent of the two and can spread rapidly, even through masonry. It occurs when the timbers reach a saturation of around 18% to 20%.

Because both require damp conditions to promote the fungi spores to grow, maintenance of the property is key. Allowing overflows to drip, gutters to block or roofs to leak will contribute or create a risk.

Ventilation is also an important factor, and restricted or blocked under-floor or loft ventilation is a favourite for helping create the environment for both types of rot.

Our Building Surveys in London pay particular attention to basements, which are more prevalent in the City.  The photographs attached were taken in the course of normal surveys in London by one of our Chartered Surveyors Daniel Stephens MRICS.

If you are worried you may have Wet Rot or Dry Rot, or the right elements for rot being a risk, our Chartered Surveyors can provide a report called a Structural Investigation, which will identify the risk, the dangers and recommend what to do about it.