dangti6 Posted November 9, 2020 Share Posted November 9, 2020 Ground workers uncovered what appears to be a French drain right underneath the back wall of my proposed extension. This runs beneath what will be the slab and out again through another footing at the front, yet to be dug. It’s about 800mm down. The water company came out to confirm it is not on their plans, but apparently in 2011 they adopted infrastructure that may include that drain. Going to try the ‘build over’ department tomorrow to see if they can shed some light on it and potentially survey it. Theres a brook about 50 metres or so away and I wouldn’t be surprised if this drain was from a ditch or something when the land was a Farm some 30+ years ago. Building control suggest it should be surveyed and if proven to be capped off, carry on as normal or if it is still in use, divert it around the building. Talk about bad luck. Can see this costing me a few quid! Any words of wisdom or ideas appreciated. Link to comment Share on other sites More sharing options...
joe90 Posted November 9, 2020 Share Posted November 9, 2020 I would build over it if possible, you don’t water building up if it is still “connected” to a source somewhere ! Link to comment Share on other sites More sharing options...
dangti6 Posted November 9, 2020 Author Share Posted November 9, 2020 I’m not entirely sure how it would be built over. Change from a permeable pipe to a solid pipe underneath the ‘slab’? So any water could flow though and permeate either side as previously? Was introduced to the building inspector today. He is certainly on the particular side, but then so they should be. Neighbours Bay Laurel there required a 1.7m trench. And being over 1.5m now required clayboard. Link to comment Share on other sites More sharing options...
Russell griffiths Posted November 9, 2020 Share Posted November 9, 2020 Can you get somebody to stick a camera down it. If it’s not in use it will save you a grand having to change it. Link to comment Share on other sites More sharing options...
dangti6 Posted November 9, 2020 Author Share Posted November 9, 2020 2 minutes ago, Russell griffiths said: Can you get somebody to stick a camera down it. If it’s not in use it will save you a grand having to change it. Yeah that’s the plan. If the water board don’t claim ownership and don’t want to offer that service (no idea if they have the capability) I will ring around tomorrow and get someone in to do so. Link to comment Share on other sites More sharing options...
Dave Jones Posted November 9, 2020 Share Posted November 9, 2020 clayboard lol. They do know how to rob the blind. Link to comment Share on other sites More sharing options...
Oz07 Posted November 9, 2020 Share Posted November 9, 2020 18 minutes ago, dangti6 said: I’m not entirely sure how it would be built over. Change from a permeable pipe to a solid pipe underneath the ‘slab’? So any water could flow though and permeate either side as previously? Was introduced to the building inspector today. He is certainly on the particular side, but then so they should be. Neighbours Bay Laurel there required a 1.7m trench. And being over 1.5m now required clayboard. And also now suspended floor instead of slab! Link to comment Share on other sites More sharing options...
dangti6 Posted November 9, 2020 Author Share Posted November 9, 2020 Believe slab is still on the cards as he insists on rebar - which is no big deal. Link to comment Share on other sites More sharing options...
Oz07 Posted November 9, 2020 Share Posted November 9, 2020 I thought anything over 1.5 and you were on suspended floor? Fair play if you can get away with the slab cheaper and better I think Link to comment Share on other sites More sharing options...
dangti6 Posted November 9, 2020 Author Share Posted November 9, 2020 Wouldn't surprise me if he changes his tune after seeking advice as he had to call the office to ask about the bay tree. Link to comment Share on other sites More sharing options...
jfb Posted November 9, 2020 Share Posted November 9, 2020 Are there actually perforations in the pipe? Link to comment Share on other sites More sharing options...
dangti6 Posted November 9, 2020 Author Share Posted November 9, 2020 3 minutes ago, jfb said: Are there actually perforations in the pipe? Yeah - according to the guys who unearthed it. I haven’t personally been in and looked myself. Found this in my folder of household documentation from the searches at purchase. Mapped back in 1962. It’s a 1989 development so I’d like to somehow get access to more information from that actual survey if I can. Presumably in 1962 it was a ditch and in 1989 the developers just put the drain in - can’t see the pipe is that old. Link to comment Share on other sites More sharing options...
Russell griffiths Posted November 9, 2020 Share Posted November 9, 2020 Looking in that access hole is any water moving. Link to comment Share on other sites More sharing options...
dangti6 Posted November 9, 2020 Author Share Posted November 9, 2020 Nope. Wasn’t full of silt or anything - which when I think of it may be a good or bad sign as it’s getting clean if it’s working/moving. It’s almost level as well. Why doesn’t it rain when you want it to. Link to comment Share on other sites More sharing options...
Declan52 Posted November 9, 2020 Share Posted November 9, 2020 Have you enough fall if you connect that pipe into your storm drain system. If you put a manhole at the back so that pipe connects into it then have all your normal connections at the back also go into it then bring it round the side to the front and out. When you get to the front will the depth be high enough to give you enough fall to connect into where ever you had planned to connect into. Link to comment Share on other sites More sharing options...
dangti6 Posted November 13, 2020 Author Share Posted November 13, 2020 Front trench was dug and the pipe was about 300mm or so from ground level going away from my site toward the road (at the rear it was about 800mm down) Rodded it and it ends near the end of my driveway. Capped it and poured the footings. Will expose and monitor. Link to comment Share on other sites More sharing options...
Oz07 Posted November 13, 2020 Share Posted November 13, 2020 Brave man Link to comment Share on other sites More sharing options...
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