ᐅ White edges on attic floorboards—is that mold?

There are white marks on the wooden floorboards in the attic.

The chimney was leaking, and water got inside. The white marks were already there before. Now, of course, we don’t know if water had entered earlier without us noticing.

Is it possible to tell if this is mold?

From a distance, it’s hard to tell. Is the wood damp? Does it have a musty smell? Have you checked it with a moisture meter? It might be worth removing a floorboard to look underneath. There are also affordable mold test kits available that can at least indicate whether it could be mold or not.

Hafenguy schrieb:

The white edges were already there before. Of course, now we don’t know if water had already gotten in earlier and we just didn’t notice.
Is it possible to tell if that is mold?

Before assuming mold, I would consider lime deposits, saltpeter, or other salts.
What exactly should be used to determine that?
To what extent do people associate white edges with mold? Mold is black, unless we are talking about white mold cheese.
Why would anyone think it’s mold now if the suspected indicators were already present before?
Why not simply open up the paneling? That’s the most straightforward step to take when there are concerns about moisture penetration.
Yes, and a remote diagnosis in a house building forum is really not conclusive either way. There are laboratories that perform proper analyses for that.