Lining a culvert with flexible drain pipe

[cjcoffin]

There is a road drain which discharges into our garden and flows down a bank in a concrete culvert about 9 ins wide x 6 1/2 deep covered with slabs. eventually disappearing underneath the next-door garden in a 6 in earthenware pipe. The overall drop in level is about 2m over a distance of 17 metres.

In recent heavy rain the culvert has been overloaded and the pressure of water has lifted the slabs flooding the garden.

The County Council has suggested connecting the inlet and outlet with 6 in pipe laid in the culvert, but because this has various bends in plan and elevation rigid pipe is not really suitable.

Can I use flexible (single wall) agricultural pipe for this application and if not does anyone have any other ideas? I have looked at 6in industrial hose but this does not come cheap (the best I have found is £375 for a 20m coil).

 

[noseall]

Has this become a recent problem or is it historic?

My thoughts are that there may be a blockage or that something needs clearing out mebbe....?

 

[Hugh Jaleak]

With Noseall there, can do no harm getting it jetted out to remove any build up of silt and/or detritus. Long term though the two sections would be better joined up properly, less opportunity for rubbish to get in there, you can 'loose' the pipe under your garden and any silt should get washed through. Are the Highways Dept paying for the work to be done?

 

[cjcoffin]

Are the Highways Dept paying for the work to be done?

I haven't found any way of convincing them to. Even though the water is all coming off the public highway they say once it is on my land it becomes my problem.

I know the outgoing pipe is clear because the council have jetted it and also during heavy rain I have seen it running at full bore from the 6 in outfall into the river.

All I need to know now is whether non-perforated corrugated land drain pipe is suitable (given it is less than half the price of the industrial hose) and how best to connect at either end it to the twin-wall and the earthenware.

 

[noseall]

You can use any pipe that is 'suitable'.

'Fernco' (thick rubber jubilee clip) connectors are ideal for connecting pipes but will only work on rigid pipe materials and would not be much good on compressible rubber tubes.

 

[maltaron]

Highway drainage is the responsibility of the Water Authority, not the County Council. Contact your WA and tell them that their highway drain is flooding your land and you want it sorted.

 

[cjcoffin]

Not true, at least in Devon, see http://www.devon.gov.uk/index/envir...t/floodriskresponsible/floodriskrespondcc.htm

 

[Hugh Jaleak]

If DIY is your only option then i'd use the 6" corrugated stuff, not ideal for that job but other than digging a trench it's probably your only option. To join either end fit a connector (usually used to join sections of the corrugated stuff together) and then the 'Fernco' couplers onto that and the existing clayware. The plastic couplers hopefully will be rigid enough to allow the Fernco to make a seal, maybe back them up with a bit of concrete.

 

[cjcoffin]

Thanks HJ, some useful advice at last.

A supplier has suggested the possibility of using twinwall cable duct, as it is more flexible and has a smooth bore, any thoughts? The MOQ is about £100 worth in either case.

Question: would the 160mm o/d of this (or indeed the land drain) be a reasonable fit in a standard rigid pipe socket, perhaps aided by mastic or surrounded by mortar? As it happens I need a slight bend ~15 deg at one end of the run and a rodding point at the other, so I could then use Fernco couplers to connect these rigid pipe ends to the twinwall/earthenware pipes which might be more satisfactory.

TIA

 

[noseall]

Thanks HJ, some useful advice at last.

Sorry that our advice has been of little benefit. I suggest that you withhold any payment that you have already sent and insist that you get a better deal for your money, trouble and time.

 

[maltaron]

CJ, I think you will find that you pay South West Water for highway drainage in with your water bill.

 

[Hugh Jaleak]

Noseall is very knowlegeable and offers a lot of help on this forum, his advice is well worth noting!

I'm not sure if the duct would fit in a 6" socket, it's not made for drainage purposes, but the 6" coiled stuff should be ok. Without trawling through the Osma site i'm not sure if they make a purpose connector from the 'Wavincoil' corrugated pipe to either 160mm plastic or the twinwall drain. Smooth bore pipe would be my preference as silt could collect in the grooves...

Ultimately is a surface water drain, provided there is a reasonable fit between the two section of pipe in a coupling, then i'd just surround the joint is concrete to seal it. Foul drainage requires more care to prevent material catching but this is only carrying runoff from the road, so should be fine.