French drain - soakaway crates?

[MisterBoy]

We've talked for a while about installing a French drain where we have some damp issues on our solid-brick walls and my understanding is these are normally filled with gravel?

I came across these plastic crates for soakaway drains which work on the idea gravel will only end up full of silt eventually:

I wondered if these or something similar would be suitable for French drains, it basically forces an air-gap? It seems a similar principle but I never saw a FD up close and personal so maybe a daft idea?

 

[KenGMac]

MisterBoy, good evening.

The devices you have posted would require a massive excavation close to the property, and the possibility of going below the foundations with the excavations needed to set in these crates.

Below is a link to a commercial retailer about French drains. [other suppliers are out there]

https://www.permagard.co.uk/advice/installing-a-french-drain

In general a french drain is simply a trench, it does not have to be all that wide? and if in close proximity to a property, suggest srtongly you do not take the excavation below the lowest level of the foundations, for obvious reasons?

In a standard French drain there will be a perforated plastic pipe at or near the base of the trench, resting on a thin layer of gravel and surrounded by similar material. Now to keep the gravel free draining, the base and both walls of the excavation are [or should be] wrapped in a Geotextile. Try google for "Terram" [other similar products available] this Geotextile allows water to pass but holds back the mud / dirt and small particles.

OK I can see a use for the devices you are considering, but as a Soak away in themselves, the trick to keeping them clear is as above, Geotextile.

Ken.

 

[MisterBoy]

Thanks Ken. Yeah these crates are pretty large so I wondered if you could use a smaller version. I hadn't realised the French design included the pipe to similarly keep it clear.

 

[23vc]

The french/aco drain channel still needs to drain somewhere. That’s either into the main surface drainage or a soakaway (cubic metre hole several meters away from any houses)