Hi all. I've just been to look at a karndean floor that's lifting every where even upstairs. Now upstairs the screed has blown but downstairs I've lifted the karndean and the screeds fine but there's a thin layer of screed on the back of the plank does anyone know what causes this?house is 6 years old and floor was installed by Taylor wimpy. This is happening all over about 100 sqm downstairs.
Sounds like a few things. Could be water (or to much) added to screed causing it to become softer almost powdery. Then no primer used on screed and pulling off powdery top layer. OR - feathered screed, no primer, pulls top layer OR - no primer used when screeding OR - laitence on conc not removed causing weakness/lifting OR - anhydrite screed and wrong primer/screed combo OR - the way its being cleaned OR - moisture OR - soft screed used and heavy wheeled stuff going over Think thats about it. Dare say theres some other possibilties I haven't thought of. Got any pics ( including pic of lifted bit)? Would help. Did you do moisture and humidity check, ask how they clean and what with?
I didn't take any pics all I can say is when I lifted the plank I could see the screed on the subfloor which was fine but no adhesive and a very thin layer of screed on the back of the tile.the screed that's blown upstairs is down to no primer.ive just emailed the client for a pic so will hopefully give a better understanding. I've done moisture check and its fine.
I'll go with Trimmer's first suggestion. To me that looks like laitence due to excess water being used in mixing and causing a chalky layer on top because the water rises to the top as it dries. The way to test is scrape it with the blunt edge of your knife and, if I'm right, you scrape right through it easily. They should have a claim with the builders.
i thought it was laitence but wasn't a 100% sure as I've only come across it a couple of times and she wants me to write her a report on it to take to the builders.at the moment the builders are saying the cause of it lifting is due to the house shrinking lol and won't take responsibility she asked if she could claim on her home insurance but wasn't sure.
Seen this before on a floor fitted on hi temp. Just peeled straight off. I'd say to much water in the screed. I no lots of ppl that put 6l in with 300 and I see this happen
This can happen if the screed has a dusty finish ! You need to take the top off with a rotary machine & sanding disc. This will take the white top off waterbase if its been mix with to much water & you can polish feather with it as well to stop that peeling ! I use mine on all screeds unless its a tiny area because you get better adhesion & no top peeling off the screed !
Only one thing to add to that.....I had someone prepare a job on a new build with water mix screed a few months ago. They used waaay too much water and it was nothing but laitence so the whole lot had to be chipped out. Did someone say at sometime Mapei Turbo 1K can stabilise something like that?
1K turbo wont fix a wrong mixed smoothing compound. It will add strength to a builders screed (concrete) tho.
Be Careful, if that report ends up in court, you will be ripped a new poo hole. Reports should be written by qualified people who are qualified to do so.
