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Posted: Sat Feb 12, 2011 2:29 pm
by Bookworm
I need to install an attenuation cell to comply with SUDS for my driveway that I am currently constructing.
Can I position the attenuation cell under the driveway as I am short of other available space in the garden ?
If so, what should be the depth and material to backfill from the top of the cell to the level of the sub-base MOT.
Thanks.
Posted: Sat Feb 12, 2011 4:05 pm
by GB_Groundworks
Posted: Sat Feb 12, 2011 4:20 pm
by Mikey_C
also search the website and you will find greater detil on soakaway design and build.
also here is a how to guide
Posted: Sat Feb 12, 2011 5:02 pm
by Bookworm
Thanks for the replies but neither reply or links actually answers my specific question, perhaps I have not made my question totally clear. I intend to install a plastic crate type attenuation cell linked to an ACO Drive Drain. The drain will run between the edge of the new drive and the public pavement, but I have limited sideways space beyond the drain run. I have researched all the information and understand the basics of installing an attenuation cell. This website does show the details for installing an attenuation cell under 'paving' but not specifically under a driveway. I need to know whether it is practical to install it underneath the actual block paved drive area and if so what depth of cover and what type of material should be used to backfill the excavation to the level where the sub-base starts.
Posted: Sat Feb 12, 2011 8:30 pm
by seanandruby
Would your soakaway be far enough away from the house?
Would this help?
or this
By the way welcome to the Brew Cabin.
The lads are correct and you should of read the index. But in all fairness it can be time consuming and it is easier to ask. Keep us informed as you progress, photos' would be good to.
I'm in Eastbourne.
Posted: Sat Feb 12, 2011 8:32 pm
by Mikey_C
as you obviously can't be arse'd to SEARCH THE WEBSITE, as instructed, try READING this page, the depth of cover can change between crate manufacture, but you'll know that from the research you have done before you posted. capping layers are also described on the website (if you can be bothered to have a good read). the whole topic of suds installations has been discussed on various other posts(feel free to have a search look and digest), but is currently in discussion here
Posted: Sat Feb 12, 2011 11:26 pm
by haggistini
not much of a book worm N P smith :p just make sure you check for services before you go digging a big hole!
Posted: Sun Feb 13, 2011 9:22 am
by Bookworm
Thank you all once again for your replies.
Let me try again !
If I excavate a hole (knowing exactly where all the services are) under the area of my proposed driveway and install an attenuation cell wrapped in geotextile and surrounded in pea shingle and backfill with two 150mm thick compacted layers of MOT to bring up to sub-base level, will I be likely to get any future local settlement in that area. If settlement is likely under these conditions is there an alternative construction detail which would prevent the problem ?
Alternatively, will discharging all the surface water through the attenuation cell make the area around the cell swell and cause local heaving ?
Posted: Sun Feb 13, 2011 9:37 am
by GB_Groundworks
Are you making a true attenuation cell or a soak away?
Attenuation holds the water back and releases it slowly into the drain to stop storm surges etc, or are you sticking a crate in the ground and hoping thevwater will soak away into the ground.
If it's the latter you'll have to do a soil porosity test First to establish the water absorption potential of your ground
If you construct it correctly and compact it correctly it won't go anywhere or go to town do a precast concrete cover 150mm thick two layers of rebar crane it in lol
Posted: Sun Feb 13, 2011 11:35 am
by haggistini
Bookworm wrote:Let me try again !
If I excavate a hole (knowing exactly where all the services are) under the area of my proposed driveway
just a warning as services are everywhere and some people don’t realize the danger just look at the two horses that where killed yesterday at Newbury after recent work disturbed and old service and they had horse shoes on not a sharp spade or digger!!!!! Giles is right check the ground conditions install as instructed and it should be fine if you seek a guarantee find a contractor who will provide this for you.
Posted: Sun Feb 13, 2011 11:45 am
by lutonlagerlout
AFAIK if you use the blue crates it is fine
LLL 
Posted: Sun Feb 13, 2011 12:05 pm
by haggistini
lutonlagerlout wrote:AFAIK
whats that now ?
Posted: Sun Feb 13, 2011 1:09 pm
by Bookworm
Thank you for your replies, very helpful.
I have yet to carry out the water test, but subject to that being okay, the intention is to place a crate/s in the ground and hope the water soaks away. Not too sure yet what I will do if the water test fails !
Thanks again all.
Posted: Sun Feb 13, 2011 2:02 pm
by GB_Groundworks
afaik: as far as i know
so you want to refer to it as a soak away really not a attenuation cell
by the way you are fine in a digger, well in all the times i ve cut through cables ive been fine hehe machine acts like a faraday cage principle like a car being struck by ligthening. all that happens is a big bang bright spark and you loose a bit of your bucket where it arcs and melts it, wouldnt want to be stood around though. watching the live jointing lads is something to behold
http://en.wikipedia.org/wiki/Faraday_cage
Posted: Sun Feb 13, 2011 2:21 pm
by Mikey_C
the rubber tracks help as well. 