Advice please 52m floor UFH - Tile Advice

[Chris G]

I have a 52m kitchen/diner/hall floor to tile in a couple of weeks (600x600) Its over electric UFH . Their sparky has already fitted insulation boards and warmup matting . I will be self levelling on top to encapsulate the cables . Is their a minimum mm height you have to go above the cables ? Should I use a fibre SLC?

My other concern is the need for any expansion joints. The kit/diner is 42m (6x7) and it split in half by original slab and extension . Now the UFh is down Iv no way of telling we're the 'fault line' is exactly if I need to fit expansion joint .
Would I get away with not having an exp joint ?

Any advice very much appreciated . Cheers

 

[Matt Bott]

If you cover the cables that should be sufficient mate, i don't believe you need to go deeper unless having to level the floor at the same time. I've just tried to find exact standards on expansion joints as i can't remember the different area based on UFH and no UFH.
when you latex make sure all the parts of UFH are fully encapsulated and the sparky hasn't made a tent around any devices with tape that could cause an air pocket and over heat.

 

[Matt Bott]

BS 5385 states that movement joints

should be placed at no greater than 10 metres. However we recommend that they are placed more frequently to neutralise the higher degree of movement created by the heating system in the screed. Maximum centres of 5 metres

 

[Flintstone]

No to expansion joint on that area, although you could put one on the door way between main area and hall if you wanted. The leveller will say on the bag its minimum thickness, as long as wires are covered that should suffice. Make sure the cold tail connection is fully incased in the leveller and not hidden in the wall. Use a good quality leveller which states it's suitable for that purpose and expect to get about 2sqm out of each bag.
I think that covers it !

 

[Old Mod]

I think that covers it !

Apart from an expansion joint SHOULD be fitted at each doorway, rooms are very seldom the same temp continually. This difference in temp is the cause of problems between between rooms.

 

[Flintstone]

Perhaps with stone, I can't see there been a problem with porcelain and I have never seen a problem of that nature, have you ?

 

[Old Mod]

Perhaps with stone, I can't see there been a problem with porcelain and I have never seen a problem of that nature, have you ?

Yes Andy I have.
It wasn't a criticism mate, just my opinion.

 

[Flintstone]

I know! As was mine mate

 

[Chris G]

Thanks for he input gents, very helpful . So am I correct in saying that I only need to put expansion joints in he door ways to hall and there is a small utility off kitchen .? And no need for one in the middle of kit/diner area ? Sometimes I guess people dont want to ruin the look of the floor with a joint. I know it does blend in if it runs along a joint of a full tile. But I suppose there sometimes a situation where It'd run through a tile ?!

 

[Old Mod]

But I suppose there sometimes a situation where It'd run through a tile ?!

It depends, you should ALWAYS mirror one that is in the substrate. So if for setting out purposes one ends up in the middle of a tile, so be it.
But it depends who does your setting out.
There are lots of tricks that can be used.
There are products out there that can colour match your grout perfectly, thing is a different material will always just look different, colour matched or not.
But you can lessen the impact with a colour match.