old 150mm foundation in sub base

[classacitizen]

Hi

Just poured the foundation for a new extension. Inside the foundation perimeter are some old strip footings for an outbuilding. These sit just below the level i am bringing my sub base/ hardcore level up to! About 20mm below. Should i remove them or just cover them over with hardcore??

cheers

[page6159]

Depends.

Are you casting a slab over the top to form a solid floor? Or are you installing a suspended floor? (block and beam or timber)