Wall mushrooms - update

[Jethro_uk]

After getting the source of damp (storm porch felt had rotted, letting rain blow into roof void, thus making wall damp) sorted, and running a dehumidifier in the room for 5 weeks, should I be surprised that there's just appeared another crop of the "cellar cup" mushrooms. In the same place the first were.

This time wall doesn't feel damp at all. Humidity meter (if it can be trusted) shows around 40% when the dehumidifier runs, rising to 50% when it doesn't.

Takes about 2 days for the dehumidifier to extract 2L of water on it's "Auto" setting.

[harryagain]

May take weeks to dry out.

Once rot is estsblished, drying out won't cure the commonest form. (Dry rot) It will need chemical treatment. Eg cuprinol five star.

[Martin Warby]

I was told different, and the wikipedia article seems to back his up

'Once established, the fungi can remain active in timber with a moisture content of more than 20%'

So when moisture content drops to below 20% it should go dormant, how easy it is to get the moisture level this low is debatable, chemical treatment can give some respite in mean time

Martin

[harryagain]

Depends on which rot you have got. It would not be neccessary to chemically treat it if that were not so. Timber commonly has more than 20% moisture in the UK even with no roof leaks. Your rot is still active even though roof is fixed

Look up "dormant."

[mgreen02]

Dry rot isn't the commonest form of timber decay in the UK and drying does, demonstrably kill it. It's a fungus, all fungi need water. Every last one. But we are not talking about dry rot.

Peziza (cellar cup) requires a lot of water and should be easy to dehydrate.

Have you tries 'tenting' the dehumidifier? They work best in confined spaces and enclosing them in polythene sheeting with the section of wall you are trying to dry would accelerate things.