Kitchen and hall on different levels

[skeebo]

Hi all

I'm going to tile on concrete from my kitchen through to the hallway (I am not having a door, just the door opening) using 300mm x 300mm x about 6mm ceramic tiles. I'm having underfloor heating in the kitchen which will raise the level by 5mm (the thickness of the mat).

My tiler said to get 5mm hardboard and screw it down into the concrete floor in the hallway to make both surfaces level to tile on.

Could he not just use a trowel with deeper notches, say 10mm deep, throughout the hallway? This thicker layer of addy would build up the level.

I that is too much could he not just build up the level of the adjoining tile and gradually fade it to the normal level of the hallway? (Would the 5mm difference be that noticible over lets say, 3 tiles?)

I'm renovating a house to move into and my budget is pretty low now so dont want to spend more than I have to but obviously dont want a botched job. Any advice will be gratefully received.

Cheers

Oh, just quickly. Is it absolutly necessary to use self leveling cement over the heating mat before tiling?

Again, thanks

[jay]

Hi its easier if you use slc makes for a better Finnish why not continue down the hallway with slc to keep the same level

[Mike]

it is advisable to use slc over the ufh mats/cables. they need to be fully covered to avoid hotspots which could lead to the cable burning out and it would also prevent damage to the cable whilst laying the tiles.

[andy8758]

Skeebo - Hello and welcome to the forum.

First off - I cannot understand any tiler recommending putting hardboard on cencrete, but something may have got lost in translation. As you are intending to lay underfloor heating, you should lay a thermal layer to make the heating as efficient as possible (you really dont want to heat the concrete do you?). Thermal boards come in a range of sizes, incluiding 6 and 10 and 12mm thickness - you can lay this using normal floor adhesive spread very thinly, and by using boards of different thicknesses, you may overcome the problem. The under floor heating is laid onto the thermal boards.

Second - nearly all tilers will lay self levelling compound (SLC) on top of the under floor heating to protect the cable when tiling on top, and to get the flatest sub- surface to get the best tiled finish.

Finally - there is nothing wrong with using extra adhesive to pad out differences in floor height - must check maximum depth that adhesive is effective before use (different floor adhesives have different properties) - most of us are forever "back-filling" differences in floor height with extra adhesive - the odd mm or 2 of adhesive are rarely noticed once the tiles are levelled.

Good luck.

[whitebeam]

No 5mm hardboard.

[skeebo]

Thanks for your quick replies and good answers.

I am now formulating my plan of attack, how does this sound?

1) Instead of thermal boards I have already bought a therma-coat insulating floor primer as this limits the rise in height of the floor (I hope this is alright!!).
2) My heating mat will be laid on this.
3) I will use an SLC on the heating mat.

Now my new plan is....instead using the SLC throughout the kitchen and hallway, could i not gradually thin the SLC out from the kitchen door to partway into the hallway to get rid of the 5mm difference? Sorry if this is a silly question but I'm trying to cut back on costs (materials and labour) and looking to add more strings to my bow by doing this myself.

Cheers

[ms.tiles]

Hi
Insulation boards reduce the time the heating takes to warm up.
The best way i can put it is that the concrete will suck the heat down and then once the concrete is hot it will come up through the tiles. A well known company have told me over the phone that without insulation boards it can take up to and hour to warm up but with boards its only 25mins. The boards will reduce electricity costs and over time pay for themselves. As somebody said above they come in different sizes so you could level out the floors with them.
Ive never heard of a therma-coating primer and couldnt tell you if that would work or not,im sure some of the pro's on here can give you info on that.

good luck hope all goes well

[jwatson]

This all depends on the finish that you want to achieve. If you are spending money on the ufh(which are not cheap). you are best taking jays advice and level down the hall (slc).
use an insulation board where ufh is to be fixed to get the best out of it and try to get a board size that will help on the cost of slc. any corners cut will only compromise on the finish you will get.
i know budget is a factor, but the finish of a renovation will be what you always see.

hope this helps you

[skeebo]

Hi everyone.

I went with the SLC in the end. Laid/poured it myself and feathered it out into the hallway.
Tiler has been in and the floor looks great.
Thx everyone for your advice.

Simon