Path of pipe though foundation

[LSB]

I am cutting a small channel through my foundations to run a 110 mm foul water drain. I need to get the top of the pipe 150mm below external damp proof. The concrete is as hard as hell. Question is do I need to allow any gap around the outside of the pipe top on bottom as  it passes through the foundations at the bottom and the lintel that will run over the top or can get be a snug fit ?

 

 

 

 

 

 

[Clark Kent]

Generally the detail is a 100mm gap all round filled with shingle 

[Russell griffiths]

Can you core drill 160mm hole through the footing instead. 

[LSB]

36 minutes ago, Russell griffiths said:

Can you core drill 160mm hole through the footing instead. 

unfortunately not as this is a conversion and the floor slab is already in situ hence drains on top of the foundations.

We need something to get the drain drop and the height below the DPC