Hi. First time post but lot of useful info here so thanks & hoping you can help out. 1955 house, recently moved in and presuming no DPM under concrete slab. Screed on top of slab is cracked/crumply/blown so that’s come off and now down to the concrete. Was looking to do liquid DPM sandwich with fball 1200/F77/1200 (or NA/1cDPM/NA but that’s costing another 30% more.. so FBall seems the way to go). But also looking to have retrofit Underfloor heating installed and this needs another SLC layer to encapsulate the pipes and fill in the castellated panels. The one they have specced for is LevelFlex which appears to have a compressive strength of 30N/mm Am I right in thinking that’s going to be a no-go with either a NA or fball 1200 sandwich? Any alternative suggestions if not? Cheers Adam
Definitely not a good Idea Any screed on top of another must be the same or lower compression strength than the one underneath Grind the concrete smooth apply the DPM straight to the concrete Prime the DPM then you could use level flex over that and then more level flex top
Is the ufh all in panels? If so the latex beneath won’t be affected. Sent from my iPhone using Tapatalk
Dpm should still be protected really. Just in case it gets pierced. You can never be too careful Sent from my iPhone using Tapatalk
This is the stuff Omnie clipplate compact ( can’t post link sorry) Adhesive backed to fix to subfloor. Pretty sure the concrete in current state isn’t flat enough to take that.
With out seeing it an epoxy DPM straight on the clean concrete then a screed over the top will do the job NA sandwich is for when the concrete is ruff to pre smooth before the DPM so as to get a consistent and affective coat
