The Accidental Smallholder Forum

Community => Introduce yourself => Topic started by: Waterfight on October 06, 2019, 07:40:41 pm

Title: Broken land drainage pipes
Post by: Waterfight on October 06, 2019, 07:40:41 pm
Hi Everyone, Thanks for letting me join the forum.
We have  this year moved to mid Wales and we are enjoying the complexion enhancing moisture filled air.
Unfortunately the 2 acres of land we now own has some drainage issues, notably a culverted stream which passes under the house . Which is in a dip.
About 100 m from the house we have discovered when excavating at intervals, that the 18inch concrete pipe has collapsed. So the stream is moving through the pipe but is constricted.
I think it will be possible to replace the collapsed sections of concrete pipe with new 450mm twin wall plastic non perf land drain pipe. What do people think? How would I make a good sealed connection between the pipes if so?
Has anyone had this problem.
Unfortunately its now coming into winter so some water is always moving through the concrete culvert.
Thanks
Ali
Title: Re: Broken land drainage pipes
Post by: Possum on October 08, 2019, 09:07:37 am
Welcome to TAS from a currently sunny Somerset (not sure how long the sun will last, mind). :wave:


I'm full of admiration for someone who is able to tackle such a task. I don't think I would be up to it. You may be able to find a more expert person if you post your query in the "Techniques and Skills" section. There are some very clever people who give advice there. :)
Title: Re: Broken land drainage pipes
Post by: Mad Goatwoman of Madeley on October 09, 2019, 01:05:10 am
Hi and welcome to TAS.
Title: Re: Broken land drainage pipes
Post by: chrismahon on October 09, 2019, 10:12:32 am
Hi and welcome. That sounds like a lot of work- if sections have collapsed for no apparent reason, [size=78%]perhaps all of it may and could be it needs replacing entirely? As you say, it's a job for a dry Summer.[/size]
Title: Re: Broken land drainage pipes
Post by: Zyg on October 09, 2019, 01:38:23 pm
How would I make a good sealed connection between the pipes if so?


Apart from it being hard work it should be a simple job.
If there aren't any proprietary concrete-plastic connectors....

1 - You could abut the plastic to the concrete as closely as possible and simply backfill around the pipes

2- If you want to do a better job of it...
       - Abut the two pipes.
       - Wrap some damp proof membrane (DPM), or other strong plastic sheet, around the join and secure with tape. About 6" either side of the join should do - wrap it tight. It is to prevent cement getting into the pipe.
       - Wrap some expanded metal lath (EML) around the join - not too tight. This is to hold the cement in place while you do the job and will act as reinforcement once the cement has set.
       - Use sharp sand (coarse is better than fine but either will do ). Make up a 2:1 or 3:1 mix of sand to cement and add a waterproof additive to the gauging water - this will make the mix more workable as well as waterproof. You may need as much as 1 to 2 25kg bags of sand per joint.
       - Starting at the bottom, have a 1"-2"  gap for the cement. Shove some cement in the bottom and push it in, jiggle it about with a stick or similar so it flows to fill the space. Then working upwards, build up the soil to within 1"-2" of the pipe and fill this with cement and jiggle. Keep going all the way round the pipe.
       - Cover with plastic to protect from rain and allow the cement to set.
       - Next day complete backfilling.

I hope this works for you. Have fun!