Damp proofing a screed floor.

[LeanTwo]

I have had a small area of an old concrete floor treated for damp.  The floor is in an old cottage and it is likely that when it was laid, years ago, that it went down without any DPM.

 

We agreed to have this floor treated as it was damp. The work done was to first apply a latex layer. I did not see this applied but it looked like it was poured on in a liquid form.  I suspect that the liquid DMP was then applied, possibly while some areas of the latex had not cured (the correct word?).  Some of the latex came up through the DPM and I was told that the latex (being oil based) and the DMP material being water based could not mix so the latex could come up to the surface. The latex showed white on the black DPM covering.

 

The builder has returned and painted a second coat of the DPM.  He says that the DPM instructions on the can say that it should dry in 16 hours.  It hasn't dried after 20 hours. We have put a fan on to increase the airflow over the surface.

 

Should a latex layer have been applied before the DPM was painted on?  Does a liquid  DPM application rely on some moisture being drawn down into the screed to dry it?

 

What might be a solution to our problem?  Any help would be great.