longest run for horizontal soil is 6 metres, but what about when u add bends

[plumber89]

hi i understand the longest run you can have on soil is 6 metres (horizontally), but what about when you add bends, is there a equation? or do certain bends equant for .25 of a metre or anything?
any advice would be greatly aprreciated
cheers

 

[Nat]

I don't think there is anything like a set reduction in length for bends etc. Just try to use 2 45 degree bends to make a 90 to avoid the water 'compressing' as it flows out or better yet a 45, small section of pipe then another 45 to elongate the bend. It's also not a bad idea to use a Y-branch tee with an M+F bend in it to make up a 90 and put an access cap in the other end of the branch. Put an access wherever you think problems are likely to occur and keep the fall at around 18mm fall in the metre.

 

[gaspastemania]

Fall is generally one in four thats what a clerk of works looks for

 

[SafeGasInstall]

i have a 45m run to price is industrial ,but is not for toilet is for wash basin .....
any suggestions on that ! will have a 4 wash basin sink to 4" pipe + 2 sink with saniflo been pumped from like 20m run

 

[SafeGasInstall]

what is the required fall on them horizontal soil pipe work

 

[Nat]

Fall is generally one in four thats what a clerk of works looks for

One in four is a massive fall, gaspastemania. That's 250mm for every metre along!

Sorry I should have said AT LEAST 18mm per metre.

 

[SafeGasInstall]

i had in my head 10 mm for every 1m of run ,is there limit how long to run 4" pipe horizontally ?

 

[Nat]

Just had a look in my NVQ textbook and it says longest branch (from wc to primary stack) is 6m but doesn't say how long horizontal run can be if it's the primary stack. I have definately installed horizontal runs suspended in car park below flats longer than 6m but was in 6inch.

Pretty sure you can find the answer to your question here, SGI:

http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADH_2002.pdf

Good luck, mate!

 

[kay-jay]

i had in my head 10 mm for every 1m of run ,is there limit how long to run 4" pipe horizontally ?

10mm per m is not a self cleansing gradient mate. you may get away with it for a metre or so in length but for the longer run the water will run faster than the deposits if you know what i mean. (like a race on a water slide) and then all the richards will choke the pipe.

minimum is 18mm per m but i think this should be increased over a longer run

 

[kay-jay]

Drainage systems are generally designed to run at a maximum of three quarters full bore. Pipe gradients should be established such that the velocity does not fall below 0.70l/s to ensure adequate self-cleansing.
A 110mm foul drain taking the discharge from a single stack should be laid at a 1:40 (25mm per metre) fall. A foul drain taking the discharge from more than one stack can be laid at 1:80 (12.5mm per metre).


from the marley website

 

[kay-jay]

Note: If you are installing a new soil stack or drainage system, or significantly altering an existing system, you will need to inform the Building Control Department at your local Council. You will need to demonstrate that the work carried out conforms to Building Regulations: England & Wales or Scotland

same source

 

[nicglee]

I want to run a soil pipe from a washing machine for about 4 metres dead horizontal with a couple of bends (and then slope to join a bath waste) in probably no more than 2 inch pipe. Can any one advise if I can get away with this? Perhaps only using washing liquid and not powder? And if I'm able to access the pipe to clean out every now and again (how often is advisable)?

 

[kay-jay]

I want to run a soil pipe from a washing machine for about 4 metres dead horizontal with a couple of bends (and then slope to join a bath waste) in probably no more than 2 inch pipe. Can any one advise if I can get away with this? Perhaps only using washing liquid and not powder? And if I'm able to access the pipe to clean out every now and again (how often is advisable)?

Dead horizontally is never a good idea. Over the 4m run you should ideally aim for a min of 72mm fall

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[Simon F]

hi i understand the longest run you can have on soil is 6 metres (horizontally), but what about when you add bends, is there a equation? or do certain bends equant for .25 of a metre or anything?
any advice would be greatly aprreciated
cheers

is the 6m rule not to be seen the same as other measurements in the building regs.
for example 40mm pipe max length 3m, but add some means of venting like a hepvo valve to go longer.

 

[stevetheplumber]

max length is for one pipe soil systems if its vented there is no real limit
fall for 4 inch pipe is 1 in 40
when i do a number two at home it goes into the thames 7 miles way work out the fall on that lol

 

[Simon F]

do they still empty straight into the Thames, I thought the Victorians changed it to go direct to the sea.

 

[TGor]

i have a 45m run to price is industrial ,but is not for toilet is for wash basin .....
any suggestions on that ! will have a 4 wash basin sink to 4" pipe + 2 sink with saniflo been pumped from like 20m run

If this is installed as a vented branch serving washbasin and sink .. it's not classed as soil as far as I know .. The maximum run for a 50mm vented branch serving 6-10 washbasins is 10 metres only (this dimension is over all bends and changes of direction) and the gradient should be between 18 & 44 mm per metre There is no limit to the number of bends in that length of run but the advice given by others regarding use of long Rad or 45's is sound.
But if you design this as above ground drainage then the drainage rules can apply .. The branch discharge pipes from the macerator should be connected directly to the drain, as short as possible and if you can put them down-stream of the washbasins so that there is a chance that the washbasin discharge will keep the stuff moving. Depending on the layout you might need to vent the appliance discharge pipes and the end of the horizontal drain.

: )

 

[kay-jay]

Well when i read the op i assumed he was confusing his pipes. My assumption was that by soil pipe he meant waste seeing as it comes from a washing machine and will branch into waste from bath hence my advice for a min fall of 18mm per metre

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