The drains shouldn't go through the concrete foundations (actually,
they can, but you'd need rocker sections either side). They should go
through the wall. If the drain is low relative to the foundation then
you should step the foundation below the drain. The steps should be
at least twice as long as the thickness of the concrete. The lintels
are bog-standard 150x100mm precast concrete lintels - no calcs needed.
Thanks for that. This is in an area where the foundations must be 2
metres due to
near public sewer that has 2m invert. I think the pipe will be over 1
metre down.
That would be a lot of brickwork over the top. Wouldn't you have the
foundations up either side of the pipe and a lintel across concrete the
concrete "walls" either side ?
Otherwise, the lintel would be supported on the underground blockwork,
which would be hard to construct one metre down. Also, what is a
"rocker section" ?
Lots of questions I know.
Thanks,
Simon.