Dry Rot Explained

Dry rot can cause widespread structural damage, as it can grow through bricks and mortar (though it can't feed on these). As such, it's the rot that strikes the most fear into home owners.

As it's sensitive to both drying and temperatures over 25 centigrade, dry rot is rarely found on exposed timbers, building exteriors or in well-ventilated areas. However, strands of dry rot can transport moisture from damp areas, allowing the fungus to spread to dry wood in unventilated conditions. It is most commonly found on the wood-wall joint.

The fungus is fleshy and pancake or bracket shaped with a yellow ochre centre when young, darkening to rusty red as it matures, due to spore production. It can often be the first indication of dry rot outbreak. The spores are profuse and may settle on horizontal services, as a reddish-brown dust.There is also likely to be a distinctive musty, damp smell.

If you find dry rot (or it is found by a surveyor) it is important to get it treated promptly by a professional (Make sure they are a Property Care Association member). Moisture sources need to be removed and the affected area must be dried rapidly. All rotted wood must be removed and replacement timbers should be treated with preservatives. Any remaining sound timbers must be treated with at least two coats of preservative.

To avoid the problem arising again, it is important to introduce ventilation pathways, a damp proof membrane or joist hangers between timber and wet brickwork. Timber affected by dry rot should not be retained without seeking expert advice.

To prevent dry rot it is essential that internal timbers are checked regularly to ensure that they are in a dry condition. Leaks from showers, baths, washing machines etc should be fixed quickly so that no damage is caused to adjacent timbers. A selection of chemicals and treatment schedules are usually best covered by professional contractors. 

Here at Restoration UK we supply a cross section of products and chemicals to use when dealing with dry rot. If you are a contractor please get in touch by phone 01509 217750