Survey Request Form

To arrange a survey or for more information on any of my services please fill in the form below and I will be in touch shortly.

Dry Rot-how bad can it get?

Posted by: Neil on 08/01/2020


I am often asked the question of how bad can dry rot get and how quickly does it grow and a survey that I carried out in Wallsend in December pretty much summed up what dry rot is capable of. The property has been standing empty for over a year and, in that time, no heating or ventilation was provided within the property. Add into the mix that the external rainwater goods had corroded and were allowing rainwater to spill onto the external face of the masonry around the bay window and it provided the perfect recipe for a dry rot outbreak. The conditions within the subfloor void will perfect for dry rot spores to germinate and once the infection was established it spread rapidly throughout the floor, resulting in the structural breakdown of the floor joists and floorboards.

When I entered the property, the desk in the bay window was sitting at a funny angle which caught my eye and as I walked towards it, with a loud crash, it dropped through the floor. Dry rot by its very nature is secretive as it thrives in dark, damp areas and often the initial signs of dry rot are very much the tip of the iceberg as the majority of the infection will be hidden from view. There were some telltale signs of the infection such as the warped skirting boards and the distinctive red dust which is produced by the sporophore (the reproductive part of the organism) but the full extent of the attack was not clear until I carefully ventured into the room and carried out a sub-floor inspection. The white cotton wool like growths are called 'mycelium' and they are made up of masses of 'hyphae' intertwining. The easy way to think of the 'hyphae' is to think of it as the roots of the dry rot infection. The 'hyphae are not visible to the naked eye until they start to overlap and build up in volume and as they do so they become visible as what is referred to as 'mycelium'. I managed to take some photos both above and below the floor so you can see the full extent of the infection and what dry rot can do to timbers if the right conditions are present.

If you suspect that you might have dry rot seek professional advice as if left unattended the spread of the infection and the damage can be substantial.

Corroded guttering was allowing rainwater to drip onto the window sill. The lack of maintenance resulted in rainwater penetrating the building fabric
The legs of the desk went straight through the floor. Dry Rot caused the collapse of the floorboards.
Dry rot in the perfect environment will spread rapidly Dry rot mycelium on the underside of the floor
A dry rot sporophore on the side of a joist Dry Rot is secretive by nature and the majority of the growth is generally hidden from view.
Mycelium spreading throughout the sub-floor timbers The Dry Rot infection had travelled across the width of the room.
Severe Dry Rot infection The desk leg can be seen within the sub-floor void.

Useful links

A short video looking at the cause and extent of the dry rot infection
All case studies