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Fixing outdoor drainage and bad penetrating damp

Posted: Wed Oct 12, 2022 7:08 pm
by eastdiyer
Hi I'm trying to fix the drainage outside and any advice would be hugely appreciated and well received!!

Basically, there is bad penetrating damp coming through our exterior rear wall into the kitchen. To complicate matters, we also want to move the bathroom upstairs and prepare for a new soil pipe being added. These things have both forced me to reach out for some help and sort this drainage situation...

I have started by removing the failing pebbledash which went all the way to the ground, i still need to replace the odd brick and repoint with a hydraulic lime mortar. However, there are some other things i'm not sure on...

1. the drain currently causes a lot of splash onto the bricks (i think it probably needs replacing with some sort of multi-inlet chamber?)
2. the concrete path slopes towards the house and i'm worried the direction of water and also rain splashback is making the wall really wet (i think the solution is putting in a french drain?) (i don't think high outdoor ground levels is the cause of indoor damp as they are 20cm below indoor floor)
3 if i need to dig out a trench for a french drain, how should i fix the pipe work (there are currently 2 downpipes from the guttering, 2 wasterwater pipies + a soon to be added new soil pipe (see diagram)

Re: Fixing outdoor drainage and bad penetrating damp

Posted: Fri Oct 14, 2022 10:10 pm
by stoneyboy
Hi eastdiyer,
From your description you are in an older house with solid walls and its very likely that the foundations will not be very deep. For this reason it may be a bad idea to form a French drain next to the house.
Better to dig up the path and correct its fall so it is away from the house.
Regards S