Matty0682

There is a window (always open) and a door leading in courtyard in the basement, so ventilation generally ok.

I live in a 200 year old property with a basement. The basement floor is s combination of flagstone and cobblestone which have been sealed (not sure what with but is transparent, see first pic). There was a smell of damp coming from beneath the basement stairs (the area was sealed off). I have exposed the area under the basement stairs. and there are more cobblestone but not sealed with anything. What can I use to seal these cobblestone? At the moment I am using a dehumidifier and letting it breathe. Or do I leave it as is? (I have removed as much soil as I can and washed them) Thanks