butt joining floor slabs

[simonjay]

I have to butt join a new floor slab to an existing one. Both slabs on 75mm celotex insulation. Both slabs to be covered in 75mm screed and tiled. What is the best way of ensuring the join does not crack or spread in the future ?
Thanks,
Simon.

 

[noseall]

If you have the same sub-soil, the same compacted sub base and the same conditions overall then there is little else you can do.

If you happen to get any heave or differential movement between slabs then you are not going to be able to do much about it.

I guess if you were to fit some light mesh in the screed, any diff' related cracking could be avoided, mebbe?

I personally would just screed the floor and take my chances.

Are you on clay?

 

[simonjay]

If you have the same sub-soil, the same compacted sub base and the same conditions overall then there is little else you can do.

If you happen to get any heave or differential movement between slabs then you are not going to be able to do much about it.

I guess if you were to fit some light mesh in the screed, any diff' related cracking could be avoided, mebbe?

I personally would just screed the floor and take my chances.

Are you on clay?

It is basically clay underneath, but not that subject to heave I believe. The BCO did not require any compressible material around the foundations for example.
Simon.

 

[Static]

You could drill a few dowels into the existing slab to provide a little continuity.. but as said if something does move then it will only crack elsewhere.. just make sure the sub base is well compacted