Constructing a soakaway

[dibsdiy]

I need to construct a soakaway to take rain fall only, from approx 20' of guttering on the garage. This is the only guttering/rain fall that will go into this soakaway. Can anyone please advise how far away should the soakaway be from the garage and how deep. Can I put just rubble down in the soakaway and cover with earth? Any help most appreciated. Dee

 

[noseall]

Dig a 1m x 1m x 1.2m deep hole in the ground, 5m from any building, fill up to the incoming pipe with no fines rubble, protect the pipe outlet with a brick frame and a slab, cover the lot with polythene and cover with soil.

 

[noseall]

P.S. if you have a clay substrate then you may be pi$$ing in the wind.

 

[dibsdiy]

Many thanks for your reply. Sorry but I don't know what no fines rubble is, do you mean rubble in small pieces? Also, how deep should the down pipe fixed to the garage go, should it go at a downwards angle towards the soakaway or should I dig down 1.2m at the garage wall? How deep do you think the actual pipe should be at the soakaway? Thank you for your help. Dee

 

[RedHerring2]

No fines rubble is rubble without the very small particles, like sand/dust.
I would guess smallest particles about 10mm upwards.

Use a rest bend at the bottom of the down pipe, lilke this:
http://www.toolstation.com/shop/Structural/110mm+Underground/Rest+Bend+110mm+875/d210/sd2868/p12565

You can get an adaptor to take the downpipe straight in.
Bed the rest bend into concrete so the top is slightly below ground level, the bottom of the bend should be about 450mm below ground, add a piece of pipe to bring it up to ground level.
The gradient from the rest bend to the soakaway is suggested to be minimum 1 in 50 (about 100mm in 5 metres) but you can get away with as little as 1 in 100 for surface water (50mm in 5 metres). (Strictly speaking, 1 in 100 for multiple downpipes only)

The pipe should enter the soakaway near the top.

A useful leaflet:
http://www.diydoctor.org.uk/project_images/undergrounddrainage/underground drainage.pdf

 

[dibsdiy]

Thank you very much for all your help, I understand now what I need and think I can do it reasonably well. Thank you again. The leaflets were also very helpful. Dee.

 

[wavetrain]

P.S. if you have a clay substrate then you may be p**sing in the wind.

Sorry nosy, but I disagree, we have a soakaway in clay soil and it only overflows under heavy prolonged rain. If the OP's ground layout can cope with occasional overflow, no problem.

Personaly, I would drain the water into a water butt(s) and direct the overflow from the butt into the soakaway or just let it overflow if possible. In fact having a water butt that overflows down the garden is what I will be doing to one of my garages in due course that currently drains into the freshwater drain, but then I do enjoy gardening. I have known some people to have a water butt but direct the overflow down the sewer drain, I would never do anything like that however.

 

[Static]

P.S. if you have a clay substrate then you may be p**sing in the wind.

Sorry nosy, but I disagree, we have a soakaway in clay soil and it only overflows under heavy prolonged rain. If the OP's ground layout can cope with occasional overflow, no problem.

You disagree that soakaways dont really work in clay soils by telling us you have a soakaway that fails in heavy rains..

 

[wavetrain]

Nosy's post implied they would not work at all. Our's works 99% of the time when it rains, but when it fails, the run off just goes down the garden which does not matter as it is pouring down everywhere anyway. Also our's is of smaller volume than that proposed by nosy and therefore if it was his size I expect it would work 100%

I explained this in detail in my previous post so Static, you are turning into the 2nd troll on this forum.

 

[intercityuk]

look at pavingexpert.com it's a fantastic web site and tells you all about soakaways and lots of other things.

good luck

 

[intercityuk]

wavetrain hope i'm not the 1st troll ????

lol

 

[wavetrain]

The 1st Troll has a forum name that begins ge....

 

[Static]

Nosy's post implied they would not work at all. Our's works 99% of the time when it rains, but when it fails, the run off just goes down the garden which does not matter as it is pouring down everywhere anyway. Also our's is of smaller volume than that proposed by nosy and therefore if it was his size I expect it would work 100%

I explained this in detail in my previous post so Static, you are turning into the 2nd troll on this forum.

Im not sure how my comment could be considered trolling.. your statement was simply a contradiction..

Soakaways don't work in most clay soils because they lack the infiltration rate and over time the plates form an impermiable layer meaning you have to dig them up and redo them every few years.. the clue is in the name "soakaway" as in soaks away if it doesnt then you created water storage.. soakaways should empty 24hrs after the rainfall..

 

[freddiemercurystwin]

A soakaway either works or it doesn't.

 

[krieghammer]

What's the implications if a soakaway is 1m from house? The pit appears to be clay soil only.

Thanks.