"sm_jamieson" wrote in message
...
I have fitted 450mm inspection chamber (had to be changed from 300mm
after correspondence with BCO (grrrrr).
I know about bedding the drainage runs in pea gravel etc. But what
about the chambers themselves ? A couple of related questions.


Bed down on pea gravel, 100mm thick, insert chamber at correct depth, fill
all round with pea gravel at least to within 100mm of chamber and the rest
with graded back fill.
This will suit all domestic installations.