Damp end of terrace - ideas for a solution - Drainage for damp end of terrace

[Renten]

Hello

* What approach to take on the side elevation/side path that suffers from internal damp below the dpc?

* A solution for a downpipe connection if a rear garden is unsuitable for a soakaway due to clay?

Downpipe

We have 1 x side downpipe that just temporarily runs into the garden (this downpipe used to go into the soil stack!) at the moment. A foul sewer is below the path that runs down the side path (see pic of it being dug up for drain survey) but rather oddly the fall is actually from the front of the house to the very back of the garden. The house is slightly below the other houses on the opposite side of the street. This nice gradient would make connecting the new downpipe ideal for a soakaway in garden apart from the clay soil. Yet to do a proper test in the garden but a proposed development next door shared it’s professional drainage test showing the geology and it does not look great - poor infiltrating soil.

In the past the garden has been flooded. We could ask utility company to connect to foul sewer but they might insist on soakaway.

Side Elevation

The side of the house has an old path right up against the side wall of the house. Plan here initially is to lower ground levels and install new flagstones that are adjacent right up to the wall of the house with a slight fall to them. I would welcome any ideas to ensure we can drain water/moisture away from the house as quickly as possible or at least try and keep it dryer. Damp is present in brickwork along the side of the house below dpc.

Front Elevation

At the front of the house, the brick pavers need repointing or relaying as they are just sat on a wet soil by the look of it. Considering lowering ground levels here with new flagstones but that could be a much bigger job.

Thanks for reading,

[Tony McC]

Are you certain that the property has a viable DPC? One of your photies shows an air-brick half a metre or so above Ground Level (GL) which, under normal circs, would indicate the DPC is well clear of the ground.

Assuming you do have that essential DPC, and that it is working as intended, then I would look at using a one-way drainage composite laid against the wall down to that layer of limestone bnlocks (what an odd thing to find! Maybe a regulating course for spreader courses on the house?) then backfill with a clean gravel.

As for the downpipe, I can see why you would be pushed towards using a soakaway, but with those ground conditions, it's highly unlikely a soakaway would work, or work well enough. I would use that survey to argue that a standard connection to either the SW or, as a last resort (and via a trapped connection) to the FW.

Does that help at all? It seems to be, more or less, exactly the conclusions you had reached for yourself.

[Renten]

Hi Tony

Thanks so much for the reply, I will look into drainage composites and that is very helpful. A few people have suggested french drains but I had them in a previous basement flat and they didnt seem to work that well, just filled up with leaves and standing water, bit unsightly then plants started growing out of them!. Perhaps having been installed incorrectly.

We do have a sort of dpc of bitumen that seems to be still doing a job of some sorts. Amazing really after 100 years but the bricks below and mortar below is damp compared to the bricks and mortar above. He is a more recent picture with the cement render being hacked off.

Sorry can you clarify or confirm - "I would use that survey to argue that a standard connection to either the SW or, as a last resort (and via a trapped connection) to the FW"

[Tony McC]

From what you've told us, yes: it sounds as though a FW connection is your only option BUT.....legeal stuff follows......I have not surveyed the site so there could be other more appropriate or preferable solutions of which I am not aware.