How do I know if I have dry rot in my floorboards or timbers in my property?

How to identify dry rot:

  • The dry rot sporophore will look like an orange or yellow ‘fleshy pancake’.
  • Orange or red spore dust which is emitted from a fruiting sporophore.
  • The mycelium strands (the vegetative part of a fungus) will be whitish grey.
  • As the mycelium ages, or dries out, it will become grey and brittle.
  • Dry rot mycelium can also be ‘wool like’ in texture or appear as a silky, pale yellow sheet growing over the timber or other building materials.

Dry rot, which has a damp musty smell, can also be found in or on masonry, in plaster and in mortar joints. It can even travel across metal. The moisture content needs to be around 20% for dry rot to germinate.

How to identify materials affected by dry rot:

  • Cuboid-like cracking can be found along the grain of the timber.
  • If left untreated, the dry rot breaks down the structural strength of timbers.
  • The wood will also look slightly darker in colour and be brittle to touch.

Things that can cause a dry rot outbreak:

  • Leaking pipes under subfloors, cellars and roof spaces and in any areas source of consistent moisture. These areas provide ideal conditions for dry rot to germinate.
  • Humidity, condensation, penetrating damp, or rising damp can also contribute to the way dry rot spreads and germinates within a building.

Dry rot can sometimes be misdiagnosed as wet rot. For further definitions see our article: How do I know if I have wet rot in my floorboards?

This answer is a guide only. Further advice should be sought regarding dry rot. Jones Melling has a team of specialists who can advise you on the best course of action regarding your property.

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