Yesterday we dug out a hole 7ft x 7ft x 4ft 3inches in the garden and seemed to go past the clay layer and into some grey matter, believing that going down this far will enable the water to soak away. Do you think this will be far enough?
I read your webpage last night and you said that if water does not come into the hole after 24 hours this will work and work well, nothing much has appeared even after the rain last night, only a few puddles and hopefully this will be the case.
What do you think we should fill this in with, I don't really fancy the concrete soakaway you advise in your web pages, I was thinking more like large cobbles on the bottom two thirds of the hole and pea gravel on the top third of the hole?
Where can I buy the above from at a reasonable cost, the building centres charge a fortune and the quarries only seem to want to deliver 20 tons?
Also how much cobbles/pea gravel do you think we will need taking into consideration the above sizes
Thank you
Mrs M
Digging a soakaway in a clay garden
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84-1093879891
I can't say whether your trial pit is suitable as a soakaway as I can't see it. What's this 'grey matter' that you've found? Is it sandy/gravelly, or is it clayey?
Assuming it is suitable, why would you then want to fill it with cobbles and pea gravel? That only occupies the space and reduces the storage capacity of the hole. Besides, using large cobbles at the base and pea gravel at the top is a waste, as the pea-gravel will trickle down into the voids between the cobbles.
If you don't fancy the concrete ring soakaway depicted in the Drainage section, then there are PVC units that you can buy that perform a similar function, but are lightweight and easier to handle. Filling a hole with all sorts of rubble is not how modern soakaways are constructed.
Quantity wise, if you were daft enough to backfill the hole, you're looking at around 2.1m x 2.1m x 1.25m (metric is so much easier to use!) which is 5.5 m3 which, in turn, is around 10-12 tonnes of rubble/rock/hardcore.
Your cheapest source depends on where you live. I could tell you to go to Charlie Love's Quarry where you can get 10 tonnes of 'cobbles' for around 80 quid, but then, you might not live in the same village as me! ;)
Assuming it is suitable, why would you then want to fill it with cobbles and pea gravel? That only occupies the space and reduces the storage capacity of the hole. Besides, using large cobbles at the base and pea gravel at the top is a waste, as the pea-gravel will trickle down into the voids between the cobbles.
If you don't fancy the concrete ring soakaway depicted in the Drainage section, then there are PVC units that you can buy that perform a similar function, but are lightweight and easier to handle. Filling a hole with all sorts of rubble is not how modern soakaways are constructed.
Quantity wise, if you were daft enough to backfill the hole, you're looking at around 2.1m x 2.1m x 1.25m (metric is so much easier to use!) which is 5.5 m3 which, in turn, is around 10-12 tonnes of rubble/rock/hardcore.
Your cheapest source depends on where you live. I could tell you to go to Charlie Love's Quarry where you can get 10 tonnes of 'cobbles' for around 80 quid, but then, you might not live in the same village as me! ;)