Suds system - Workaround for shallow drains?

[Sync700uk]

Firstly,congratulations on the single most informative website of it's type that I have come across. I've learnt how much I do not know

I have a problem of shallow main drains and problematic building constraints from 'She Who Must Be Obeyed'.

I'm looking to provide surface and groundwater drainage for the reworking of a patio area . The ground is heavy clay, prone to flooding and slopes towards the house. The only viable outlet is the main SW drain.

I was planning a simple system of flexi land pipes ultimately connecting to the SW drain with an adapter. On excavation, I find the main drain to be 4 - 5 courses below DPC (say 350- 400 mm) . However existng ground level is only 3 courses below DPC,( say 200 mm). I don't see how I can sink a land drain far enough below ground level for it to be structually sound and functionally effective even using reduced minimum depths

The Linear drains attracted a frown from SWMBO and the same has expressed a wish for 'no little steps' in her patio area so raising the patio is not an option either. I have doubts whether the 'bodged job' tactic of gravel/stones against the brick wall would give us the drainage power needed. On a brighter note, SWMBO wants gravel between the pavers. This opens up SUDS :cool

The terram drainage composites are nice but way too expensive in horizontal use. However, I did track down a website promoting a Terram product called 'Advantage'. It says it is used for drainage, including wrapped drains but I can't determine whether this product can be use as a horizontal drainage composite membrane. The question therefore has three parts. ???

1/ Can I use the 'suds solution for a patio' you've outlined in the SUDS pages where the drainage trench will be up against the house?

2/ Do you think I could use the terran advantage membrane as a horizontal composite linking into it. This is the website
Terram advantage

3/ By my calculations the the drainage trench will only be about 225 mm below the cobbles/pebbles on the surface in order for pavers not to exceed DPC and a sufficent fall to exist from the bottom of the trench to the SW drain connection. Can I get away with that?

Any advice much appreciated :blues:

[Tony McC]

1 - SUDS is probably not going to be all that easy on a site you say is prone to waterlogging. It all depends on the percolation rate for your sub-grade.

2 - Terram Advantage is simply a 'general purpose' geotextile. It is NOT a composite, so it won't work as you imagine as a horizontal drain.

3 - This goes back to Q1. I think your best option is likely to be a linear channel of some description.