Safe depth of french drain beside house

[bobby5000]

Hi all,

The front garden and the land down one side of my house gets water logged. Heavy soils and slightly lower ground to surrounding land.

Planning to install three French drains through the front garden connecting to the storm drain. Along the side of the house, planning to replace the two old clay gullies with new plastic ones, along with the pipe connecting them. The new pipe will have perforations in the top and will sit at the bottom of a gravel filled trench. The French drains through the front garden will connect to the pipe/gullies described.

Idea is that this will all shift a lot of the water off the property and particularly away from the house, drying out the front garden and down the side of the house.

One concern I have though is that the new gullies and connecting pipe will sit in a gravel trench, which will replace the heavy soils currently built up against the foundations (it tops out at 2 bricks below DPC). Is it safe to have a deep trench of gravel running alongside the full side of the house? Can it harm the foundations somehow? Would it actually draw water towards the house from the soils beyond, by being less dense? I want water away from the house.

Thanks in advance for any advice you can offer.

Bobby

 

[bobby5000]

Main reasons for asking were:

- seems that replacing the heavy soils that are up against the masonry with something less dense could result in movement?

- somebody once told me that a stone trench up against the house would allow water to run down through the stones and wash away the soils from below the foundations.

- I understand that the building regs now require a distance of at least 5m between house and soakaway. This gravel filled trench alongside the house would seem a similar thing to a soakaway. Same issues?

For context, the house is a bungalow built in 1961.

 

[SpecialK]

You will be fine. Crack on.