Joined: July 2004
||Posted: 09 Dec. 2019,16:15
Yep - you can't reduce pipe diameter when adding more drainage.
If your BCO will allow you to put both houses onto a single 110mm dia drag-out chamber which then links to the 150mm dia pipe, that would be ideal, but you need to get this approved before steaming ahead as some BCOs insist on being at 150mm dia minimum as soon as there is more than one property involved.
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