Trench block compressive strength

[WWilts]

Structural engnr specified 7N aircrete for inner leaf of cavity wall up to ceiling of ground floor. Above that, 2.9N aircrete suffices for SE.

 

Builder favours a course of aircrete trench blocks atop trench fill concrete footings, sitting on bed of traditional mortar. My hunch is that trench blocks should also be 7N to convey the load to the concrete footings. Could anything less than 7N (eg 3.6N) suffice for the trench blocks? 215mm high, 440mm long, 300mm wide

 

 

Edited August 23, 2021 by WWilts

[Oz07]

7n only usually used on 3 storey. SE knows best but you can ask the question