Will tiles crack on floor joint?

[skyblob]

New extension with 125mm EPS foam under slab, joins existing solid concrete floor circa 1974.
If I ceramic tile right across regardless, do I expect tiles to crack on the joint?

Opinions?

 

[^woody^]

do I expect tiles to crack on the joint?

Dunno ... you tell us?

I would not expect them too, but they might

 

[Symptoms]

blob - if the new slab settles even a tiny amount then you could get a crack on any 'bridging' tiles. Consider positioning the grout line above the old/new interface; any cracking will be to the grout - more easily repaired.

 

[Kes]

I had a similar worry about 2.5 years ago - original concrete half floor with new concrete slab (and a crap job the builder did too, I wish I'd done it myself). Anyway I asked the tiler to use flexible tiling cement across the joint. It was gvery expensive, but there's no crack yet.

I think that it just staves off the day of reckoning. Eventually I think that the floor will crack, but then we'll have a large carpet in place...

 

[^woody^]

If the OP is really concerned about movement (perhaps expensive tiles) then he should incorporate a proper movement joint in the slab and tiled surface.