Power flow floor vs lvt help please

Update. Had a self employed fitter come round and he asked loads of questions about the screed, when, depth and under heating and if it’s been on etc. Coming back to take a rh reading. He said as long as it’s under 75% he will start fitting.

Does that sound right or not?
Looking on line and everything is saying it will need screeding and then fitting

 

Needs screeding with a calcium sulphate based compound regardless as to how good the slab is

 

Also you won get a proper reading with one return, on anhydrite I'd be leaving a box and taking a reading every day for a week, the rh can fluctuate on that stuff

 

its been around before for those older than earth itself, it had a run in the 80's until people wised up a bit.
Nothing stays stuck to it for long including primers and screeds as the surface powders away as it cures over the next few years.
With underfloor drilling ply down is out, nothing sticks to it, the stuff really is a quick grab your cash bodge of screeds.
My advice, sell the LVT and buy carpets and cushionfloor.

 

Jumpax over it


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treat it for what it is and the stuff is good 100% of anhydrite failures are down to not knowing what your dealing with and treating it as a sand cement mix, grind sweep hoover hoover prime prime neat prime then latex with calcium sulphate screed and your golden, make sure you prime all the way to the edge within a few milimetres and id probably recommend stopgap 1100 over the nc110 PURELY because 1100 has a minute amount of cement in it which seems to help it bind better and would give you a timny bit of tolerance, id use nc110 as better product but I know what im doing

 

Grind it until you see aggregate, then as pf flooring says

 

Why do you disagree?

 

200Sqm is a decent size area, ring the manufacturer of smoothing compound technical department the number will be on the bag and drums and ask for a site visit by the area rep and they should provide your with a full specification for the work to be carried out. We have overlaid anhydrite screeds for over 15 years and yes they can be complicated to deal with.

 

Very true, getting correct information from the builder can be difficult.

 

I had exactly same on a 600m2 job last year. Builder was adamant it just needed sweeping, priming and a screed . I refused to entertain it until I had Uzin rep come in and tell him direct the procedure. In the end we went with the spec uzin gave us and builder was still saying it's over kill. "We do this all the time" he says....hmmmm yeah mr builder

 

The comment someone made above about getting the underfloor heating on is a good start, make sure you commission the heating as per the manufacturers recommendations,This can take a week or longer as the heat has to be gradually increased never switch it up straight away as this will cause issues with cracking of the anhydrite screed.leave the heating on for a few weeks to help with the drying process then have a manufacturer of the smoothing compounds carry out a site visit. Do not put rugs or temporary flooring down as this prevents the anhydrite from drying.