I wondered if anyone could give me some advice on what they can see from my photos please. The floor has been laid over the course of the last 18 months over a water Wunda underfloor heating system following a larger extension in the kitchen and a smaller one in the lounge. I hadn’ have started to notice that where the heating pipes are, I am starting to get raised tracks in the LVT and areas of dipping. On advice from Karndean, I lifted a plank and found this Could anyone explain why this has happened and what I will need to do to sort it out please? (Although I think I know the answer ) Thanks for your help
Looks like there's some cracks appearing in that last pic. Screed should have been thicker over them pipes. How long after it was laid that you started to notice this? And what temp do you run your ufh on? Adhesive transfer doesn't look to clever either
There has been no leaking I think from the pipes as the water pressure has remained constant and the temperature has been limited to under the maximum allowed from the lvt supplier. I do not recall the time between the screed and laying off the flooring but can see the cracks too. The extensions were probably concreted between 3 to 6 months before the flooring prep was started
It could be a non compatible screed aswell as not the minimum thickness required. Must be a thin coat for the pipes to be showing through.
Lines showing through like that looks like damp being pushed through by the ufh. Looks like the slab below is damp
I was wondering whether it is that the floor was laid without a suitable waterproof layer so moisture is rising up. It makes sense. If anyone has any pictures of anything similar, that would be great. What are my options if it is this as I have no money left in the pot, I’m overwhelmed by the enormity of the problem? and the person who did it flippantly said , “If it had to be completely redone, I’d have to go bankrupt” which equals no chance of any financial compensation to sort it out
Was the wunda boards secured correctly to the sub floor ? How deep was the compound over that ? Doesn’t look prepped correctly
Very risky bonding to these systems. I think a floated floor is the best way to go over these. Lots of potential issues and a mix of manufacturers products involved. From the builders base to the floor finish. Often installed by plumbers. LVT is very unforgiving. Your cheapest option may be remove the lvt and float a new floor over it. If the screed or the wunda panels are lifting or blown you have a bigger problem
Hi Merit, I’m about to lay the same system but on a first floor. I was advised by quite a few people that a floating floor would be a bad idea due to the heat and the potential expansion and contraction. I then looked at porcelain tiles, but was a bit concerned about the weight. Now looking at Amtico, but I too can only lay 10mm of screed. I’m now thinking possibly porcelain tiles might be safest. Sent from my iPhone using Tapatalk
Is it possible the screed wasn’t entirely dry before the LvT was laid? Or the pipes not pressurised perhaps? Sent from my iPhone using Tapatalk
This again is where you will get conflicting advice. Some manufacturers will say you cant flaot a floor over ufh and some will say you must only float a floor over ufh. The main problem is relying on that type of subfloor to be stable/suitable for your flooring. In my opinion they rarely and its very hard to guarantee the work thats been done to install them. I dont tile so I cant really advise on that but most tile systems use a decoupling matt to help with installation.
Hi Lisa, did you get to the bottom of why this happened? We have the same issue although a different brand of flooring but still LVT. Thanks.
