How to cover a large soakaway?

[nomail]

I have a Well soakaway (to pump water into before it runs clear and could be pumped into the loft tanks - all now redundant) and a soakaway that takes the septic tank output before (presumably) passing it to the leach field. Both are brick, just over 4 feet diameter and both need the covers sorting out in a way that gets them flush with the lawn and have a standard access hatch. I've investigated prefab concrete rings but these are expensive, heavy to transport and would be unsightly. My only other thought is to try to set-up something (concrete lintels?) across the soakaways, a couple of feet below ground level, to support paving slabs and a cover, then to pour concrete in situ to complete the pad. Comments and counter suggestions are very welcome ...

[Bob Minchin]

I presume there is no need for these lids to be watertight so just the lintels should be OK with just a few inches of soil for the grass. Do you need hatches? They would be difficult to in corporate with the lintels unless you made a custom steel frame to slot the ends of the lintels into and transfer the load to some full width lintels. Basing on a traffic quality hatch might be helpful. Alternatively fill em with rubble and other crap and soil on top. Might get a bit of sinkage over time but sprinkling a little topsoil on the grass and it will re-grow through to compensate.

or rubble plus concrete then soil?

[Jonathan]

We covered ours by putting L-shaped steels across the gap and then putting paving slabs onto them.

Jonathan

[Chris Hogg]

We have a soakaway taking rainwater run-off from the roof. The soakaway itself is approximately a 5 ft cube inside, with a roughly rectangular access hole in the roof. When we moved here some 17 years ago, I investigated it. You can get down into it, crouch in it and turn around, but nothing more than that. The sides are made of pot blocks (these bastards

laid on their sides without mortar.

The roof was made of one or two sheets of corrugated iron laid across the top, with concrete poured onto that, possibly with some wire netting embedded in it to reinforce it but I can't remember for certain, and probably a bit of shuttering around the access hole. The concrete was about 3 inches thick. A large heavy piece of slate covers the access hole, but a 2ftx2ft concrete slab would do just as well. The whole structure is buried, partly under the grass and partly under a flowerbed, and is covered by about 3 inches of soil so is totally invisible and not readily accessible.

The property dates from 1952, which is when I assume the soakaway was put in. The corrugated iron was rather rusty when I looked, but the concrete seemed OK, and it's all still OK AFAIK, so it's lasted about

65 years.

[GB]

It depends whether you have a sense of humour. I favour a light covering of sticks with grass and leaves on top. Then you stand the far side, and beckon your soon-to-be-ex-friends towards you. Such fun! :-)

[nomail]

The septic tank soakaway is a bit smelly when the current lid is lifted so that needs to be air tight, but the other soakaway doesn't need to be. I was thinking of using regular manhole covers for access, set on a mesh of lintels but couldn't see how to join the short ones, maybe the answer is to put the X and Y lintels at different levels and build up from the lower ones

[nomail]

Interesting, but I'd be worried about corrosion and the whole thing suddenly letting go in 10 years time

[nomail]

Thanks. That's along the lines I was thinking of, but I was going to use lintels to bear the load - maybe I'm over-thinking it ...

[nomail]

At least they wouldn't need a burial if they fell into the septic tank soakaway - they'd already be interred ;-)

[Jonathan]

Ten years later it still looks good.

jonathan

[Muddymike]

I covered one years ago by simply using shuttering ply supported by a length of 4x2 with a hole cut in the ply for a standard manhole cover, an up-stand of shuttering was fitted around the hole then 6" of concrete with a bit of rebar poured on top, and the manhole frame set into it. Once set I cut the 4x2 where it passed through the manhole, removed the up-stand shuttering, fitted the cover, but left the shuttering ply in place. This gave me a level concrete cover. If you want to grass over it just set it at a lower level and build with up with bricks to raise the cover.

Mike

[fred]

Get the steel galvanised or cold galvanise it yourself

[nomail]

I did consider something similar (didn't think of putting support timbers where they could be sawn out afterwards) but was concerned about the concrete dropping a little as the shuttering rotted away, that's partly why I was thinking of using slabs as a base. Hmmm, if there were a few holes around the periphery of the shuttering (over the soakaway brickwork) the concrete would create support pads for when the wood rots ... that may be the simplest way forward. Thanks!

[Muddymike]

Thinking about it I now remember using a couple of old joist hangers to support the temp 4x2 so that when I cut the middle out the ends just pulled out! I lived there for 15 years and never noticed the slab drop due to the ply rotting. You idea of a few holes in the shuttering above the tank wall sound like a good one.

Mike