Damp and pamments

[Ukerica]

Hi.
I have the original Under floor in my house of just soil and joists. Newer floorboards .I have a concrete? Hearth that I have painted many times but goes white with damp.
I would like to cover some of the hearth with some pamments (can’t do whole area as too large and will be covered by rug).
1. Should I put something like bitumen paint under pamments?
2. will damp make pamments white in time?
3. if I treat with bitumen under pamments will it just push the damp up under the concrete that’s left uncovered (under the rug)?

hard to explain. Sorry

help?
thank you

 

[88v8]

Hello and welcome.

Pictures might help... use Photobucket or similar.

Pamments are porous so if they are laid on damp, then the damp will come through. However, if you lay them on a bed of NHL 2 made up with sharp sand 1:4, and point them with NHL and silver sand, then the bed and the pointing will be breathable and the pamments will not go white.

As you suspect, if you paint with Blackjack or Synthaprufe, that will send the damp sideways, although having said that natural wool rugs will tolerate a certain amount of damp if laid on a breathable felt underlay.