Thank you for your help. We are in the process of buying a house. In the garden is a sort of summer house - timber frame, breeze blocks, felt roof, and some terrifying fungus growing up through the floor! I'd be so grateful if you could help us identify it. We've been given mixed advice about whether we can kill it or if the building needs to be demolished. It seems to be coming through only on the walls through gaps between the walls and the floor. But maybe it could be growing under the floor too? If you could suggest what it is and how to get rid of it Id be very grateful. Thank you, Gaby
You could power wash the structure which would help clean the walls and floors.
You can also use a fungicide on the area.
If the conditions are damp and shady, you may see the fungus return.
There are thousands of fungus and lichens so identification is difficult.