Is this expanding foam?

[slangivar]

We are currently getting our house rewired and found this under the floor boards. I initially thought it was expanding foam but it's very soft to touch. As soon as you touch it it crumbles to dust.

Can anyone confirm that it is just very old foam and not something else we should be concerned about

 

[DIYWell]

Strange one.

Doesn't look like a fungus if that's what you were worrying about.

My experience of decades old expanding foam is it does crumble, but it tends to be much darker

 

[ktuludays]

It looks like stuff I have in my wall cavity. It's very crumbly when touched.

 

[Deleted member 174758]

It's expanding foam - it hasn't gone the usual (with age) yellow to brown colour because it hasn't been exposed to UV light.

 

[slangivar]

Great, thanks for confirming. I'll stop worrying now.

@ktuludays. It's at the edge of the room so you've possibly just answered our question about whether the cavity has ever been filled.

 

[^woody^]

It's cavity insulation foam, not the stuff you get in a can. Dense but brittle.

 

[slangivar]

Thanks woody