well done for getting the first one,it might be another plastic/ceramic junction you need to find at the site of the blockage or the "soakaway" might just be a pipe end in the natural.
Fairly sure the pipe carries on down the garden because that would end it only about 10m from the house and it could run for another 30m but mostly because there's a section where the garden drops a few steps and just after that it feels like I can feel an gravel / rubble line about 20cm under the grass. The rest of the pipe seems to be about 60 - 70 cm down so there's a lot of digging to sort this out!
well done for getting the first one,it might be another plastic/ceramic junction you need to find at the site of the blockage or the "soakaway" might just be a pipe end in the natural.
the garden will recover
You're right, a bit more digging and it turns out the next blockage is where the pipe ends in a buried rubble drain. That drain also appears to be blocked. I've no idea how old that is but it's just a collection of brick bits covered with a thin piece of metal, which has long since disintegrated, buried and now largely silted up.
I'll probably dig out the trench and replace the french drain. I'll still put in the new rodding point but I want to make it so that its cover is not water tight. Then if it blocks again it will overflow through the rodding point and not next to the house. That means a warning that it's blocked and no water pooling next to the house.
I'm guessing at the construction of the rubble drain based on what I can see is already there as being basically a trench filled with rubble covered with something to prevent too much soil falling through and then buried but advice is welcome.
I'm guessing at the construction of the rubble drain based on what I can see is already there as being basically a trench filled with rubble covered with something to prevent too much soil falling through
basically yeh, just a hole filled with rubble.
Building control round these parts is usually happy with a 1m cube hole filled with rubble (half brick max), capped with a polythene sheet (dpm stuff).
When I did soakaway for my house I used plastic crates wrapped in membrane - but only because I scored a bargain on ebay.
I capped it off with concrete garage sections - but only because they were there.
And I fitted a silt trap immediately behind soakaway rather than fitting individual traps at downpipes.
the best shape of hole depends on the local soil,slopes ,volume to be soaked etc etc this linky is a bit technical but covers the issues fairly clearly.
In my case I am planning on building a long french drain. So instead of a cube it will be a trench and allow it to flow down the length of the garden. It is on clay so may well not soak away but if it does reach that point it should flood across the bottom of the garden which would have been the natural result without the drainage but now it won't flood near to the house
OK - a few buildery questions about french drains.
20mm or 40mm aggregate to fill it?
DPM (impermeable keeps the drain clear) or woven geotex (permeable so helps drainage but will it let silt and mud through from the surrounding soil) to cover it?
20mm to 70mm is a fairly usual grade of rubble ie nowt too small or big .
clean graded hardcore ,ie no plaster or mortar and screened to remove the wee bits is among the cheapest suitable stuff but depending what is available locally bargains can be had .
try to avoid new aggregate as it has an extra "quarry tax" on it .
a quick call to building control should get your local approved materials list as different areas have local preferences.
iirc geotex was favourite a while back in the london area
even more techy stuff but this linky has a lot of useful design info.
ppppp
iirc across a slope works better than down a slope where it might puddle at the low end but i think that sort of stuff is in the recent linky.
In this case down the slope is better. It will then join to the existing french drain further down. By that point hopefully enough has soaked away to not puddle. If it does then I just repeat the exercise of remaking the french drain down from that and if I have to go far enough then it will eventually reach the ditch at the field edge and join the natural drainage channels.
gregotyn
Joined: 24 Jun 2010 Posts: 2201 Location: Llanfyllin area
Posted: Fri Jul 22, 16 1:17 pm Post subject:
Give me a clue what area you are in as I have a friend who wants to loose some rubble/stone and so you could probably be selective, by taking some and if you have a long enough trench all of the hardcore. He is sited in the Llanfyllin area by Welshpool, Powys. I haven't told him yet!
Give me a clue what area you are in as I have a friend who wants to loose some rubble/stone and so you could probably be selective, by taking some and if you have a long enough trench all of the hardcore. He is sited in the Llanfyllin area by Welshpool, Powys. I haven't told him yet!
Thanks for the offer but Wales is too far away as I'm in Sussex. Though it seems appropriate to be offered rubble from Llandfyllin (yes I know the 'd' shouldn't be there but the pun works better with it)
Last edited by Jb on Sat Jul 23, 16 7:52 pm; edited 1 time in total
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