Threshold for needing expansion joints

[i_am_fubar]

6x3m 100mm thick concrete slab with rebar mesh. Blockwork building on top.

I'm getting mixed results on whether I should add an expansion joint. What's y'all thoughts?

South Hampshire (UK), sheltered location.

Cheers,
Fubar

 

[jj4091]

If you mean in the slab you shouldn't need expansion joints with rebar. Blockwork might but you would need further advice about that.

 

[i_am_fubar]

Question was for the slab. For the blockwork, I plan on putting in some expanded steel mesh every few courses to minimise cracking.