I have a crawl space with a concrete slab floor that was poured on sand about 12-14" above the water table with no poly vapor barrier below the slab.
For the most part, the crawl space is dry. (no intrusion of water pooling on the concrete)
There is white efflorescence in patches on the floor.
One section (100 sq feet) the surface of the concrete is loose and wet. While the main structure seems solid enough (no cracks nor broken pieces and was difficult enough to punch a hole through) it is very porous and damp there.
Cleaning the loose scale and soft stuff off the surface is a given but will your Xypex concentrate work to seal the slab and prevent a further ingress of water from underneath?
What preparation needs to be done with the efflorescence elsewhere on the slab?
It should be noted there is no drain in this crawlspace and any effort to wash with large amounts of water will result in a pool under my house...
Posted on 06 Mar 2017