Soakaway size

[gazza176186]

Hi,

I am having to dig a soakaway for a patio that is 4m by 3m (12m2)

I have dug a hole (so far) 500mm deep, 400mm long and 300mm wide.

Is this going to be big enough? I have looked at the math sum for volume using 50mm average rainfall a hr (found online) v=12(50/3000) to get 0.200m3. But his does not tell me the size of the hole I need.

Thanks for advice/help

 

[freddiemercurystwin]

A soakaway for a Patio! Why bother? Just lay it to a fall. Technically it depends on the type of soil in your garden and how well it drains.

 

[gazza176186]

The patio ends at a retaining wall so the water would build up. I am going to put a gully in so the water needs to flow to somewhere. How would I find out how it drains, The soil appears to be normal, maybe a small amount of clay in it.

 

[freddiemercurystwin]

Technically http://www.eden.gov.uk/planning-and...nce-notes/rainwater-soakaway-design-guidance/

or

http://www.pavingexpert.com/drain08.html

Or you could try and have a friendly chitchat to the building control officer who deals with your area, chances are he'll know exactly what type of soil you have and whether its suitable or not. Of course you may get a grouchy git who'll be less help than a chocolate teapot!

Or you could just whack one in say 0.4x0.4x0.4 and chances are it'll be fine.

 

[gazza176186]

Thanks for that, Ill make it at bit bigger just to be on the safe side, I think and leave it at that.....