Is using tar paper a good idea as a moisture barrier?

Question

on concrete walls and floor in a basement? I plan on using a hydraulic cement on the walls for maximum water sealant, but I plan on building walls in the old coal room I have that is 10x13. I want to put something in between the concrete and walls and have only been able to come up with the idea of roofing tar paper.
Would that work? Or is there some better idea anyone might have?

Answer 1

15# or 30# felt would work as would visqueen (6 mil), but I'm not clear what you are doing.



If the existing cellar walls are allowing water in, then you need to coat the exterior walls (positive pressure side) with a waterproofer. As far as I know, there is no homeowner product that will stop water intrusion from the negative side.



Neither felt nor visqueen are moisture preventers. These products are more like vapor barriers, but are not going to stop water intrusion.

Answer 2

6 mil or heavier polyethylene would be best. Asphalt paper is not vapor tight. It is like tyvek a vapor retarder.

Answer 3

3 or 4 mil plastic might be better.