Jump to content

French Drain found digging footings


dangti6

Recommended Posts

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.

 

FA6C407C-7618-4E26-A229-785D3A265E18.thumb.jpeg.c0fb13c07c4e8625b991892a461e5de1.jpeg

 

695BCF92-385D-4ECA-8927-49BE2C930967.thumb.jpeg.61506a72f47502eb1a73d313e9f2a5ee.jpeg

 

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

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

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

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

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.

 

26CDD1A2-9455-4B06-A5B9-2B1C98B2A9D0.thumb.jpeg.22a2171d72cc0c3bb8299474e277625d.jpeg

 

985645C0-CB7E-4018-BC54-78D544014E5E.thumb.jpeg.56cebcc5add18022a4a5ebc3f9f75426.jpeg

 

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

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

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

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

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...