What size twin wall ??

[Furniss]

The fields at the back of this farm all slope towards it - looks like its been a problem for years - we are down to do some work there in the new year but first job will be to sort this problem.
plan to start with a bund along some of back turning it into a ditch which I will cut, most of it is going to be open ditch to an existing ditch but a length of about 40m is going to have to be piped in.

Whats the consensus on pipe size needed ...... I would say the video was taken at peak flow and there is lots of fall.

Dropbox

www.dropbox.com

 

[Richard Hunton]

I'd say 600mm depends what you can get easily the bigger the better

There's a company called aquaspira that will make you the pipes to whatever size you need.

 

[JD450A]

600mm with loose clean stone fill.

 

[Furniss]

I'd say 600mm depends what you can get easily the bigger the better

There's a company called aquaspira that will make you the pipes to whatever size you need.

Cheers but im down in France - will stick to the standard sizes

600mm with loose clean stone fill.

Yep will surround it in clean stone - usually use a 20/40 clean

600mm was my thoughts too - but there was a lot of water ......temptation is to go bigger to a point but not too big as to be wasting the guys money.

 

[CPS]

Personally I'd be aiming at putting an open V ditch around the perimeter. If not possible then at least 600mm filled to the top with clean stone.

 

[Furniss]

Personally I'd be aiming at putting an open V ditch around the perimeter. If not possible then at least 600mm filled to the top with clean stone.

Yep that's the aim but some has to be piped in unfortunately

 

[JD450A]

Yep that's the aim but some has to be piped in unfortunately

Go bigger stone mate. We run 75 clean for this sort of work. Perforated twinwall too.

 

[Furniss]

Go bigger stone mate. We run 75 clean for this sort of work. Perforated twinwall too.

The bit that is to be piped will pass through a 40m long area that's 1m - 1.5m deeper than everywhere else, , it would be dangerous left as a ditch because of where it is and the depth , so tbf it wont be doing much in the way of drainage it will be only a carrier for these occassions - once we get through the high ground it will run into a new ditch- so not sure if there is any benefit to having it perfed re the stone....we are having a delivery of 20/40 clean for other jobs so I thought one heap was the way to go

 

[Komatsu]

......temptation is to go bigger to a point but not too big as to be wasting the guys money.

You won’t be wasting his money if your keeping his farm dry, and it’ll be to late when the pipe is full and over flowing.....and let’s be honest, with the way everything is going at the moment with the weather I’m sure he’ll be appreciate it.

 

[fred]

as 300mm is a quarter of the price of 600 i think id go for 4 lots of it in pea gravel topped by clean 70 mm

 

[JD450A]

as 300mm is a quarter of the price of 600 i think id go for 4 lots of it in pea gravel topped by clean 70 mm

4 lots of 300mm will carry exactly the same amount of water as one 600mm pipe. Infact it will carry less due to the friction on the pipe wall.

 

[Furniss]

You won’t be wasting his money if your keeping his farm dry, and it’ll be to late when the pipe is full and over flowing.....and let’s be honest, with the way everything is going at the moment with the weather I’m sure he’ll be appreciate it.

I thought someone say that ,and true I have to make sure that what I put in can do the job, but you cant just put in something unnecessarily large and expensive either

as 300mm is a quarter of the price of 600 i think id go for 4 lots of it in pea gravel topped by clean 70 mm

Yep it's an option though there is an argument that 4x300 could block easier with debris ( branches and such ) if it's not looked after

 

[Komatsu]

4 pipes will be 4x as many problems, you’ll find that the bottom two will silt up a lot quicker and the force of water through them won’t be strong enough to “self clean”, also it’s a lot easier to make a nice head wall round one pipe at either end rather than try and do one round 4, (which you’ll have to do to stop the water washing the gravel in between the 4 pipes out).......cheapest usually turns out to be the most expensive I’m the long run.

 

[JD450A]

4 pipes will be 4x as many problems, you’ll find that the bottom two will silt up a lot quicker and the force of water through them won’t be strong enough to “self clean”, also it’s a lot easier to make a nice head wall round one pipe at either end rather than try and do one round 4, (which you’ll have to do to stop the water washing the gravel in between the 4 pipes out).......cheapest usually turns out to be the most expensive I’m the long run.

As previously said, 4x 300mm will only carry the same amount of water as 1x 600mm pipe anyway.

 

[Komatsu]

As previously said, 4x 300mm will only carry the same amount of water as 1x 600mm pipe anyway.

It was reading as if it was the cheaper option but doing the same job

 

[JD450A]

It was reading as if it was the cheaper option but doing the same job

Na, quarter the price, but with 4 runs needed it'd be the same cost as 600mm, plus the aggro and extra labour of putting 4 runs underground.

Same logic as people that put multiple 32mm's in rather than one large bore run of potable water pipe.

 

[Komatsu]

Na, quarter the price, but with 4 runs needed it'd be the same cost as 600mm, plus the aggro and extra labour of putting 4 runs underground.

Same logic as people that put multiple 32mm's in rather than one large bore run of potable water pipe.

Well that is true