in the process of installing retro fit UHF. Removed floor screed then applied latex SLC to level it out. Advised to prime using a water based primer before laying the delta insulation boards. Left the SLC a month to dry out then applied the primer. Left that a week to dry but it still felt tacky. Being novice diy people we thought that was normal However when we walked on it yesterday it’s peeled off in large pieces that are like cling film. Now in the process of removing it all. Any ideas what we should do now ? Can we just lay the delta boards on top of the latex screed? Grateful for any advice. Thank you (sorry it’s so long)!
The builder used a SLC from B&Q and doubt very much whether he primed the concrete before it went down. The concrete had been down for many years.
Can you explain why please. The SLC seems to have bonded to the concrete - it’s the primer that’s come off.
Well a quick responce is..... Your primer you state is water based and your concrete you say how been down many years. At what point did your builder carry out a moisture test to ensure that both his SLC ( a water mix bought from b and q) and his primer (water based) would not be affected by any moisture in the ( been down a long time) concrete. The next phase of possibilities as to why your primer is peeling off is endless
No he didn’t carry out a moisture test. So what is the best way forward? Take up the SLC and then what? Thank you.
The SLC may seem bonded but if your concrete has any moisture issues which may not seem apparent it will come up and effect your water based primer...... you may also find your SLC is actually not bonded it’s just sat on top of the concrete...... hit it with a hammer if it cracks and lifts it’s not bonded if the hammer bounces and leaves a hammer mark then it has
But if it’s not moisture tolerant an you have moisture coming up through the floor you won’t get rid of it without a dpm. Check your UFH specification see what it states
Thank you. The room had also been replastered about 4 weeks earlier so no doubt this moisture may also have had an impact. What a mess! We used this method a few years ago when we did a couple of other rooms but guess we were just lucky! Will also go and get a moisture meter to check for damp.
I doubt you will be able to go and get the correct meter for testing without spending a few hundred pounds....... a simple test is place some clear polythene or fling film on the floor with silicone round the edges to form a seal and sit the polythene on top of you get water droplets forming your have moisture
Thank you so much. The latex floor screed had bonded but it’s turning to dust no doubt because it’s a poor product! Now being removed and will take your advice and see if I can find a flooring professional locally. The room in question does have a damp membrane but it seems as if all the moisture in the screed has been sucked out turning the product back to its original form!
