double seal access chamber spec'd
 

I need to use a 300mm mini-access chamber inside my extension (where 2
soil pipes meet) as screwfix supply (floplast brand), which is the
usual type with plastic risers and plastic lid. It is not spec'd as
double-seal. The plans required double-seal. Would the usual approach
be to cast a separate double-seal manhole cover into the conservatory
floor ?
This would give the extra peace-of-mind of actually having three
seals !
Simon.