Hello everyone, From the off id like to make clear that im not in the flooring trade, but am a keen DIYer and like to think im pretty competent with most jobs, but at the same time i dont mind being told when ive ballsed up! Which i obviously have this time, im just after some advice to rectify my problem. So, i knocked 2 ground floor rooms together and it resulted in a roughly 4.5m2 area being between 8 and 15mm lower than the other room. I soon found myself on the internet looking at the huge range of self leveling compounds available. And after speaking to a buider i know (i know not a screeder/flooring fitter, but has 35 years plus in the trade and does alot of renovations and has done a fair bit of subfloor prep with screeds etc) he said just use any no frills self leveling compound, i think he actually suggested a Wickes brand one, but i went for Mapei 1210 as the reviews online were almost to good to be true and worked out at 8quid is for a 25kg bag, so decided id go for that. Ok, heres what i did. The floor to be covered was about 2/3rds concrete and 1/3rd quarry tiles. I removed all loose material by running an old taping knife over the floor then swept and hoovered it. I then primed the floor with a 1 to 1 mix of water/pva and let it dry completely. Then mixed up 2 bags of mapei 1210 in one flexi tub with 10litres of water and started pouring in and troweling out across the whole area. then mixed the other 2 bags in the same way and poured in and troweled it in, i actually used a 10mm tiling trowel (as i thought it would help knock out any air) The floor came out looking perfect. poured it on a cool day about 8degrees, made sure the heating stayed off in that area of the house for 3 days while the floor cured. THEN!!!, over a week later a few small cracks started to appear, which i could see widening almost on a daily basis. Then about another week after first noticing the cracks (today) i decided to inspect abit closer and realised it sounds hollow and has blown in most areas. Realising its got to come up i chiseled a small section up this evening and its clear its just not stuck to the floor below at all. My guesses for the cause are. Up tp 16mm laid but pack only says up to 10mm Incorrect primer used Mix instructions state 4litres of water per bag, but i used 5 as every review i found suggested using ATLEAST 5litres per bag to help flow. But i fear it may have weakened it. As i said above i need to redo to floor and would like to find out what ive done wrong so its done right next time. Im glad i didnt go ahead and tile it all straight away!!! Thanks for reading guys, any input woukd ve great
Hi Steve, As you know you made three fundamental errors. 1- used pva as a primer. It doesn’t work as it breaks down. 2- applied it too thick. Usually if you want to go thicker than 10mm you need to add aggregate. 3- put too much water in! This is the main reason and for this reason alone it will fail! I would recommend sticking with mapei and use their renovation 3240. That goes to 40mm as it’s got aggregate built in! Don’t over water and use Mapei acrylic primer. (Eco prim t - I think???) Good luck!
Thanks Floorever, So the over thickness caused the cracks due to lack of aggregate. And the blowing was caused by the PVA primer, well not working lol. Everydays a school day Thanks again
All the items pointed out are a good cause but also if your floor doesn’t have a functioning dpm under the concrete and tiles then mapei renovation is not suitable. A latex mix moisture tolerant floor leveller would be more suitable, bulked up if needs be with an aggregate and then another skim coat. Water based levellers also tend to be very strong so it must be correctly primed and prepared. Your fail safes are ardex n/a. F ball 1400 ultra bond or any product similar.... I use eurocol 902 if you can get hold of it
Get it all smashed out and out the way and just get it done by a pro. It's failed once, this time around for you to do it properly is going to cost you alot more plus you have no idea if your floor needs damp proofing. Save yourself the headache and just pay for a pro to sort it out for you.
I love hearing there's no prep work as the builders have screened it Sent from my SM-G950F using Tapatalk
Ardex 1c or Fball f77 would be my go to but depends though as you may be able to use a roll on system out the tub which is like paint rolling the floor. Personally I'd epoxy dpm it IF it's needs damp proofing considering price wise....But it's not as simple as it sounds. Best bet is to call in a pro and let them do some moisture tests etc then take it from there. Using pva as a primer would be your main issue here and it probably is a dry floor which means it's just a case of getting it prepared properly from scratch. Don't let your builder give you anymore advice either
Honestly get in a pro, you need a rh% test doing and unless you want to sink near a grand on testing equipment or rent it out and not know how to use it properly it’s going to save you money and headaches in the long run. Sent from my iPhone using Tapatalk
Agree with everything above, if it’s an old house and you’ve quarry tiles, you definitely need to consider the moisture
