Yes it’s completely random. Some areas well adhered, some the backs of the tiles have no adhesive at all. And seems really weird on a single tile you can get one half well bonded, then a crack in the screed, and on the other side no adhesion at all. They used ivc high temp adhesive, and for the bits already patched up karndean high temp adhesive (crossing the streams there are we with amtico flooring ) - that adhesive seems to work better in this setting.
Now wouldn’t it be funny if your mate in Essex who had probs with renovate is the guy who fitted this job !? When anything goes wrong like this you wish you’d asked 50 more questions of the trades installing, but realistically as a consumer I should be able to rely on pros to do their jobs correctly.
Thanks, if we end up ripping up the whole lot and going again I’ll be asking for the mapei compound that has been tested / approved for use over wunda.
There should always be damp tests before fitting. I wouldnt have fitted the product until the heating had been commissioned. I,ve had problems before in fitting with the temp in the house being too low.
Thanks. Reading everything here it sounds like the most likely cause is the cold house during the install, and even though the temp was turned up slowly you’d imagine a fair bit of moisture to be trapped given the approach, and crack. Neither the fitter nor plumber seemed remotely concerned about the temperature in the house or the wait til a later date to commission the heating. I would have expected the fitter, given he’s covered everything in levelling compound and laid the floor on top to be more thorough, but then again he turned up not even knowing what a wunda ufh system is, and how it differs from other wet ufh systems, so seems to me he was winging it.
Hi all, the solution you posted and discussed here is precisely what I’m planning to install in my 2008 built Cala Home in the Borders. In my case I’ll put the Wunda system on the chipboard subfloor, and then screed to 5mm followed by Amtico Signature planks laid in Herringbone. May I kindly ask for your overall views and advice? are you happy on balance with the outcomes? what would you do differently if you were me? many thanks Nick
The following week, the floor fitter arrived to begin installing Amtico Spacia, using small planks laid in a herringbone pattern. He started by priming the floor and applying Level It Renovate. The amount of latex required turned out to be more than double what he had expected and quoted. I accepted the additional cost, understanding that he was not very familiar with the Wunda underfloor heating (UFH) system. The design of the product meant that some channels in the boards were not filled with pipes, naturally consuming more latex. This would typically use more latex than an installation over a UFH system embedded in screed.
i have just looked over a job that requires lot install the client currently has down a new underfloor heating system made of a polystyrene channeled out for the pipes to run through , the date sheet say to lay over with instamac product , i have spoke with these and they don't like the idea , spoke with FBalls won't entertain the idea , mapei how ever will allow renovation screed to be installed , not sure wether this will , work , i was just wondering if any one else has had the same issue .
It says instarmac to be used but instarmac say they don't like the idea??? Or have a I read that wrong? I've only ever used Renovation & CL plus over these type pipe systems but at a depth of around 14mm minimum and had no issues. I've made sure I've primed the hell out of it also. The CL + has less meterage by the bag so use Renovation instead when I have one of these. Just got to make sure the boards and pipes are fully secure with no movement whatsoever and I pour in 2 separate coats.
Thanks for replying rugmunch , that’s correct instamac are recommended on the data sheet of the polystyrene insulation, but however don’t feel anything over 6mm thick will work for them , as the coats of screed get thicker the tensile Strength increases . Maybe by priming adds an extra Level of strength to the polystyrene top coat ensuring the screed dosnt blow , I seem to be getting Mixed opinions on the sub structure , Mapei renovation possibly the way to go With prime a grip 2 coats ?
These systems have so many issues. Get a fully written spec from someone before you do anything. As you’ve already experienced that’s no straight forward
