The Brew Cabin

DPC on 1920 house at 2 bricks (imperial) below internal solid floor level. (cavity wall) Top of gully at DPC level. Ground around house inc tarmac and concrete 9" above DPC.
I lowered ground to 3" below DPC and gullies at same height. All surfaces made to fall away from house.
New extension (metric brick has regulation DPC at internal floor height. I had to take out a course of brick to newly formed inspection chamber to get access to self built garage. Foul water has flooded area outside house three times in 20 years when 6 shared drain has been unable to feed into overfull main sewer. House is downhill from sewer which is 20' below road Choices seem to be cure the flooding and have rising damp or cure the damp and put up with the flooding. Builders I I have asked shrug and say "Hmm!" Any ideas?

Re foul water flooding -
Isn't this a matter for the water authority? Have you asked them?

(Edited by JonD at 3:26 pm on Aug. 19, 2004)

Without seeing the site and checking the invert and cover levels, it's not easy to suggest what might or might not work. Rather than ask "Builders", who often have little experience with drainage issues, have you thought of asking a drainage specialist or a groundworker?