Drainage pipes through filled cavity

[LaChab]

I'd welcome thoughts and advice on how to deal with drains (110mm) going through the (filled) cavity below the oversite slab.

 

Having glanced through Part H, I don't fancy the built in method using rocker pipes and four flexible joints.

But for the lintelled method, how do lintels interface with concrete blocks? Do you need to use bricks round each pipe?
How do you keep the cavity clear for 50mm round the pipe when filling it with concrete?

 

I'd like to get the drains sorted before the bricky lays the blocks, but that seems tricky.

[Mr Punter]

Get the lintels in and fit shuttering either side of where the pipes are going before you cavity fill.

[George]

They can block around and lintel over. I've be tempted to get the brickies to build a closed cavity (build blocks across the end of the cavity) where the drainage pipes are, to act as the formwork for the cavity fill.

[LaChab]

@George @Mr Punter Thanks for the suggestions.

 Is it reasonable to ask the bricky to cut the concrete blocks to incorporate the lintels, or is it best to use brticks round the openings?

[joe90]

IMO, get the drains in and let your briky sort it out, he will have done this before.

[LaChab]

@joe90 Sounds like good advice! After so long doing everything myself, I find it difficult to "let go".