New to me, looked at a job last week and thought it was anhydrate but its apparently hemihydrate! They don't get a laitence so don't need buffing. Still needs priming tho! Any1 else seen these or had any issues with them? Gotta stick down 15mm engineered 260 wide over ufh so need it to behave!
whooooooooooosh straight over my head lol , never heard of it so would be looking it up to make sure I didnt bugger it up
It is a Modified anhydrite screed. Basically its anhydrite with a additive or as they call it a 'binder' i think it is. Apparently it dries without a latience. However you need to treat it the same as anhydrite. It must be fully cured. You can not apply a surface dpm and you can not apply a cement based smoothing compound unless a acrylic barrier primer is applied. Personally i would not go teh acrlic primer route and a cement based compound. We are hearing of a lot of failed anhydrite subfloors using this method. Personally i would use a anhydrite smoothing compound. However, i have never seen the above subfloor in the flesh nor am i a pro on them. I only know the above after a long conversation last year with a specialist. (a europen specialist anhydrite manufacturer)
Cheers Matt. The good thing is its flat as a pancake so won't need screeding. Noticed ball have just brought out one of those anhydrate levelling compounds
I've tiled on them a couple of times in the past and you can't get much smoother or flatter. It's because it's so fluid when it's poured.
You would be amazed at how some people can get the stuff very uneven. As you say, it should be pretty much spot of flat. Personally i cant see how its possible to get a poor finish but its defo possible !
We use a lot of a Synthetic gypsum, one for concrete, screed, asphalt and another flexible for over timber,metal pan floors, metal stairs, the company is called SCHÖNOX, the gypsum ones are called AP and APF , similar to Fballs 700 flex , To can get it from bond it, real good stuff. Worth looking at,
Came across some anahydrite the other day, its lucky I called it correctly as my boss didnt realise and when he asked the builder he thought it was powerfloated, otherwise it would have blown, had p131 and 300hd then spacia 40m2, pricey to sort out for the boss, one of the firms I sub to didnt correctly identify anahydrite and put a load of spacia with 300/p131 down and its all blown, they have a hefty bill to sort that all out as from what ive heard its a fair few plots on some new builds.
had one over a yr ago previous fitter laid colonia, it all blew to buggery called me in, i called it as an anhydrate floor 121 and fast track 30 went down fine... month later the lot blew.... everywhere... Called f ball, got their man to do site inspection for me floor was more damp than initial readings, suspected leak in the u/f pipes, tho no pressure loss was registered.. i hate this type of floor glad more manufacturers are bringing in specific screeds for these.
Myself id use 121 and 1100 to play it safe but fball told me as long as its dry and you use acrylic primer then 300hd is suitable, id belt and braces it though if it were my job and stick the 1100 over it
ye they said so long as 121 is used i could please myself what screed i used id still rather not have to deal with thse floors tho as youve said, 1100 thats what i'll be using from now on
