Advice: is this a slab failure of extension floor ?

[Jonathan Wild]

So, I'm in need of a kitchen refurb on house bought two years ago. The house has had a single story extension to extend the kitchen and to create a garage. But my biggest worry is the floor and potential cost to resolve.

Along the join of the old kitchen floor and extension slab there is either a crack or expansion gap in the concrete itself...I have removed floor tiles and part of kitchen cabinets and obviously cracked screed to expose the concrete. It's a very straight crack or gap a few mm in terms of height difference.

Just wondering if this is an expansion gap or something more serious to worry about.Extensions been in place for 20 years.

Externally there are some cracks in the mortar but told they were thermal expansion. So hopefully not subsidence.

 

[SpecialK]

Is that where the original wall would have been? I would guess its been filled with concrete to join the old to new?

 

[Jonathan Wild]

Yes, that's where the wall would pretty much be.