200mm internal diameter ducting built into trench blocks supported by lintel.

Drainage placed centrally to the ducting.

Remaining space within the ducting is then filled glass fibre insulation.

Sections of non-corrosive shuttering material carefully cut around the drainage entry.

Do not fix the shuttering to the substructure walls.

This is to allow the drainage to move within the ducting without the risk of vermin entry.

Alternatively, the drainage can be built in solid to the substructure using brickettes and supported by a lintel.

Flexible joints or rockers are required when built in solidly (Drainage flexible joint details in 5.3.14 within 150mm of substructure wall).

On this occasion, shuttering has been provided to the opening and filled with a lean mix concrete.

Cap off the pipe work to ensure no foreign material can enter the pipe work.

Pipework has been marked up in concrete for identification.