Dry Rot

Dry rot is the most serious form of fungal decay in timbers, it is caused by Serpula lacrymans spores that eat away at the parts of the wood that give the timers its strength. It will cause the affected wood to dry out and crack over time and as a result, damaging its integrity. Dry rot can grow and spread in low moisture content in comparison to wet rot, and if not identified and treated promptly it can spread rapidly, destroying much of the timber. In cases where the supporting timbers of a building are badly affected by dry rot, the structural integirty of the building may be at risk of collapse. This worst-case-scenario would be prevalent in dwellings that have been derelict or un-inhabited for a period of time, but shows the importance of having dry rot ammended promptly.

An added complication of dry rot is its ability to grow through masonary. When treating dry rot, it is often necessary to treat adjoining walls with a fungicidal barrier to eradicate all traces of the Serpula lacrymans spores.


Identifying Dry Rot

Fungus has different stages and will appear slightly differently in each stage:


Spores - Red and brown in colour -similar to rust and dusty in appearance.

Hypae - The germination phase of the spores once they have come into contact with wood with a high mositure content. This appears as grey strand that give a vein like appearance through the wood.

Mycelium - This appears as a fluffy like texture, similar to cotton wool and is white or grey in colour. At this stage it will spread through masonary to seek out wood sources.

Sporophore - Resembling a flat red / brown coloured mushroom, this is the phase where the fungus once again begins to release spores.


in addition to the above, lack of moisture in the wood can cause the timbers to warp and shrink and as a result, timbers affected by dry rot are often brittle and will be easy to break by hand. Along the grain of the wood you may see a significant break or crack in the wood known as 'cuboidal cracking' which is usually accompanied by the Hyphea stage of the fungus life cycles.


If you are concerned about dry rot in your property, please use the contact us feature for advice or to arrange a free site inspection.