Stains on Floor Boards That Could be Damp Damp can be a major issue in the home. Find answers to questions or post your own here.

[cbernardojr]

Hi!
I'm new here in the forum. I live in Leeds and started a refurbishment in a house from the 50s.

Today I removed the flooring from the living room and the underlay (with damp isolate metallic foil) and found some black stains. I tested with the humidity device and got 10% on the damp.

I could not access what is underneath but there is no pipes under the stains.

Any ideas about what I should check?

Thanks
Carlos