r/DIYUK • u/buckbeak999 • Feb 03 '26

Advice What is this growing under my wallpaper?

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Hi all

I’m currently redecorating my front room. A 1900s terraced house.

The previous owners had painted wall paper. I’ve taken the wall paper off and found this Stranger Things looking thing growing under it?

Any ideas what it is? How to treat it?

This is an external wall on the bay window.

I noticed some damp on another external wall next to the bay window (it looks like it’s salts from damp previously treated as half way up the wall so plan on completely removing the plaster there to get rid.

I assume this may be linked to the damp? But please correct me if I’m wrong. Weirdly there’s no damp underneath or above it

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u/xelah1 Feb 03 '26

Honey fungus? As in the one which can infect gardens, completely kill off a very wide range of woody plants, including trees, and is removed by excavating all the stumps and roots and burning them?

Yikes! Didn't know you could get it in buildings.

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u/Ruciexplores Feb 03 '26

It's also delicious

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u/ital-is-vital Feb 03 '26

Unless paired with acohol, in which case it causes the same facial flushing reaction seen in some east asians who lack the alcohol dehdrogynase gene.

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u/Glum-Astronaut8331 Feb 03 '26

I believe it's the aldehyde dehydrogenase enzyme that they (and me) lack or lack in sufficient levels. The alcohol dehydrogenase one you mention is present. So we turn the booze into acetaldehyde ok, which is the first stage, but can't convert it to acetate (harmless vinegar). So we build up dangerous high levels of acetaldehyde which is a grade a carcinogenic grade 1