hello, got a job coming up where i need to latex over the divi mat underfloor heating, subfloor is concrete, does it matter what smoothing compound to use???
Yes it does there are a few that are compatible, check with technical first and tell them the type of mat it is, however in most cases the sub-floor temp shouldnot and cannot go above 18 degrees celcius.
Alot of ufh matts tend to rise up when you latex over them, the shop I use to work for used one that you covered with a mesh to stop it
A lot of guys trowel a layer of rapidset tile cement first as it holds it down a lot better. They give it three hours to set and then give it a layer of slc so it can be covered the same day
thanks for the replies, its about 30m2 so just wanted to float over it , but just wondered if it matters to what screed to use. ie ardex, fball, tremco......... :?
Personally I use Ball Stopgap 300 for that but it will need two hits to cover it properly and you'll need to fix it down the best you can to stop it floating up (even with the mesh). A hot glue gun works well as sometimes the tape doesn't grip.
I did a job where the builder supplied the latex tremco sx300 to go over heat matts first time I've used that latex but was a really good latex
