Rising UFH matting.

[Sean Kelly]

I’m currently working on my own kitchen floor. I asked our builders to lay the 18mm ply 20mm below the hallway floor level. Of course, when I got home I found that it was laid at the same level as the hall. I have now primed the ply and stuck down 6mm insulation boards with flex rapidset. I then lay the matted UFH and then poured ‘Level it one’ SLC over the top. I really mucked up on the amount needed to cover approx 30sqm. I got 10 bags, but then realised (after I had poured 5 bags) that I needed more. Off to Topps to buy 6 more bags. Then it was another trip to buy 2 more bags of the stuff! Some parts of the UFH mat kept rising to the top of the SLC.

One 25k bag should cover 5sqm @ 3mm. So I assumed that 1 bag should cover 2.5sqm @ 6mm. I was expecting a thickness of between 4.5mm – 5mm, and that is why I only bought 10 bags. Luckily this is my own house as I would be seriously out of pocket if I had quoted for 10 bags of SLC.

I finished pouring the SLC yesterday @ 17:00. Do you think I should leave tiling today?
Also, there are some bits of UFH matt sticking out of the floor surface. Should I carefully cut/snip/trim these bits?

I found that the UFH matt was quite curly, and I had to use about 5 rolls of duct tape to stick it down. I also had to cut the matt several times to get the angles and the coverage right for the ‘L’ shaped room and utility room.

This is my first time using UFH, and SLC, and modular tiles. I hope to get the tiling done b4 Monday!
Cheers
Sean

 

[dagger]

is photo a] the worst bit? is it flat and level with an 1800mm level?

 

[Sean Kelly]

Dagger, there are about 7-8 bits like that. Just standing proud by about 1-1.5mm. I've just taken off the battons around the edge and found that the thickness of the SLC ranges from 4mm-15mm !!! The overall level is pretty flat though. The tile i'm puttin on is a porcelain rustic tile. i.e. not like a polished sharp edged tile that will show even the slightest lippage. Do you think another pour of SLC over the affected areas will do the trick? Cheers Sean

 

[jay]

hi sean you will find you cant just level here and there as you will develop humps in floor that you will notice scrape bad areas carfully dont damage wires and apply a thin layer over most of floor leave over night to dry next ufh job try to avoide duct tape get some spray on adh and a glue gun (hot melt)hope this helps

 

[Sean Kelly]

Thanks Jay, I read so much about UFH on here, and I did read a thread about using spray glue. However, I read about it about 3 hours after pouring the SLC !! What's worse.........mucking up my own installation or a customers? It's all part of the learning curve I guess. Cheers Sean

 

[dagger]

if they are minor bumps, just use a 20mm wide, 10mm deep half round trowel.

you will iron it out in adhesive!

and as someone said dont put more leveling down unless you can see a dip in the floor!

 

[DHTiling]

Also if that is just the netting on show, then use a scraper and flatten that bit down...carefully looking for cable... and as dagger say's use a level to check for flatness.