Concrete as a subbase

[GlenR]

I have recently compacted 10 tonne of 1'' dolomite as a subbase for my blockpaved driveway. the subbase was solid, 170mm thick. the problem i have is that i get water seeping from a neighbours garden into my garden and under the subbase does not drain away?

i woke up the following day and the sub base had gone from solid to soft (because of this water) i am really not sure what to do.

can i now mix all this dolomite (once dried out) into a concrete and re compact it down as a semi dry mix?? will this solve my problem. and also what would then happen to the beddign layer, would that turn to mush or hold out??

i simply cannot stop the water comng in so i need options??

any ideas??

[GlenR]

Sorry, forgot to add, what strength should i mix the concrete??

[Tony McC]

An interceptor drain between you and the neighbour. Using a concrete base in place of a flexible sub-base just brings a whole new set of problems.

Something like the structure shown here would do it....

[GlenR]

I really feel as though an interception drain would not work as the amount of water i get in my garden in unreal and the soil around the driveway is terrible at draining anyway. i am at the bottom of a hill and get swamped everytime we have even the lightest rain.

i have already fixed in the edgeins tight against the neighbours fence so i dont really want to rip this out and put in the drain you mention.

If i were to put in the concrete base - you say a concrete base can cause more problems, can you or anyone elaborate on this?

if i were to put in this base, what would the compacted bedding layer of sharp sand stay firm or become mush?

Any help anyone?

[GlenR]

Anyone??

[Tony McC]

Bloody hell! You're impatient, aren't you? No reply in less than a day and you're bumping the post? Strange as it may seem, most of the regulars in The Brew Cabin have to go out and earn a living and don't hang around in here all day just gagging to answer questions as soon as they appear!

You can read about the problems associated with rigid bases beneath flexible block paving on this page.

You say you don't want to re-do the edge courses along the boundary with the neighbour, but you're proposing to excavate all the sub-base and turn it into a concrete. That *must* be more work. If you don't want to disturb the edge courses, why not install a linear channel inside the edge courses and allow that to function as an interceptor?

[GlenR]

Tony, sorry for being impatient and thanks for your advice.