do i prime before latexing if putting dam on top? if not can this blow of the floor? as it can blow in a normal situation where no dpm is required if i don't prime. or do i have really diluted mix so the primer can't break down?
No primer if Dpm on top it will break down, if you are putting a dpm on top if has to be moisture tolerant probably be acrylic or latex and will stick to the floor, a waterbased wouldn't stick to the floor with no primer but couldn't live under a dpm.
Thanks for for that, what stops it coming of floor if dusty etc? So if I do another job is there any point in priming at all? If your saying it will stick to the floor without?
Something like Ardex R3E for beneath a dpm, but it's dear gear but it's also top gear.. I've been back and forth with the question of prime don't prime under a dpm for ages. I had issues with pin holing from just using the damp down method. I got "don't use a non moisture tolerant primer beneath dpm" from Ardex tech (< Collin), and "you're ok to use p131 diluted 1:7 from f-ball" (< Graham). My advice is ring the tech of whatever product you're using. Your question is obviously pretty critical, so I wouldn't take the chance..
Simply do teh job the correct way and thats always apply a moisture suppresent to the subfloor. Not a smoothing compond. Amazingly other countries dont have latex based compunds as a U.K product only. . So if they dont have them what are they putting down first ? ANSWER - nothing, dpm first.
"2 coat DPMs Matt? Some floors are rough so you won't get away with one coat" Plus even after grinding, the concrete can be pitted which can result in pin holing in a one coat..
Last week on site the other firm doing the karndean dpm'd straight over concrete floor (new build) with ardex 1c, next morning viens had appeared so ardex rep said give it another coat of 1c. I always thought it was NA first, Dpm then NA (so a sandwich) but according to the rep "not for that type of concrete floor"....have I missed something?
If it had white veins it would have been a hair line cracks in the floor and that's the moisture in it. Mario showed me some pics of one last week.