What Rot is this Rot?

[Nicobobinus]

Attached are a couple of photos of a mystery fungus in the cellar:

It seems to be coming from the soil behind the a stone retaining wall where the water main enters the house. It's pure, brilliant white and has spread even further since I took the pictures.

So, fungal experts, what are we looking at? Is it dry rot, ready to spread to the floor joists...?

 

[DAZB]

This may help...

What Is White Mold and Is It Dangerous? - PuroClean HQ

White mold is a term that applies to many species of mold which can grow in homes.

www.puroclean.com

 

[Munroast]

I don't think dry rot would have originated in soil outside the house, it would come from rotten timbers within the house, so if there is not significant signs of dry rot already in the house, then I very much doubt this is dry rot. Probably some fungus that grows outdoors that shouldn't be a problem to your house.

I'm no expert though.

 

[Nicobobinus]

Here's a couple more pictures (under slightly different lighting) of an outbreak near the hole shown above.

 

[Munroast]

is it salts ? (probably more technically known as Efflorescence)

we used to have an old property with a cellar, some parts of the cellar were particularly damp and these white salts would appear (althogh i don't recall them forming such fascinating and intricate fern like structures as yours do).

we had wet rot and in other places dry rot, and the Dry Rot (the one you have to worry about) never looked like what you have - or at least the version of dry rot we had (3 outbreaks (1 serious) in 27 years) never looked like that, there could be other versions!

 

[Odds]

Anomoloma Myceliosum

 

[Nicobobinus]

is it salts ? (probably more technically known as Efflorescence)

we used to have an old property with a cellar, some parts of the cellar were particularly damp and these white salts would appear (althogh i don't recall them forming such fascinating and intricate fern like structures as yours do).

we had wet rot and in other places dry rot, and the Dry Rot (the one you have to worry about) never looked like what you have - or at least the version of dry rot we had (3 outbreaks (1 serious) in 27 years) never looked like that, there could be other versions!

Good suggestion! It's definitely a fungus though.
Here it is again, now growing under the cavity drain membrane...


Thanks for helping relax me that it's not dry rot!

Anomoloma Myceliosum

Did that suggestion come from a reverse image search...?

It's definitely not growing on old, dead branches, which is where that species prefers to grow.

Now, should I leave it to grow, or attempt to spray fungicide behind the membrane...?