Waste pipe fall

[plumb_know]

I was installing about 2metres of 50mm waste pipe and put a fall of 50mm per metre, when boss looked he said he would of made the drop shallower. I looked it up in JTL book and it states you can have a drop of between 18-90mm per metre on 50mm waste pipe and was just wondering what your thoughts on this are? What are your preferences of fall you put on waste pipe and also do you agree with the JTL book of 18-90mm fall?

Just after some more experienced views

thanks

 

[quality]

40mm per meter for me

 

[tamz]

20 - 25mm /m

It is also about aesthetics so do what your boss tells you.

 

[village idiot]

your boss had a point. Waste pipes should be 'self cleansing''. So too much of a fall is not a good idea, me thinks. I do not personally work out the fall per se. I just place my spirit level and use the bubble to determine fall of my choice. Not the most technical, but works all the time.

 

[helpsy]

I always go at min of 20mm per metre

 

[IDCHAPPY]

your boss had a point. Waste pipes should be 'self cleansing''. So too much of a fall is not a good idea, me thinks. I do not personally work out the fall per se. I just place my spirit level and use the bubble to determine fall of my choice. Not the most technical, but works all the time.

That's what my old plumber Journeyman used to do, a touch of the bead as he used to call it

 

[plumb_know]

Yeah it looked fine, just he told me to install it and when he checked after it was glued just mentioned he would of done it at a bit shallower fall and to ask on here what others thoughts were. Surely anywhere between 18-90mm is self cleansing as that is what the book states it can be run at? Thanks for comments everyone, I will do it a bit shallower next time

 

[helpsy]

I guess a lot of measurements that are stated have been made by time and money spent researching various criteria.... And these were the best results.

 

[Koogatubac]

Most of the time its cosmetics. Small boxing or large boxing.... Think i know what custards want...

 

[kozak1968]

1 in 40 is 25mm per metre. 1 in 60 is 15mm per metre. These are the usual self cleansing falls. There is a proper calculation to work out hydraulic mean depth. Because plastic is smoother and has less friction resistance than cast iron, the falls can be less.

 

[sheff paul]

I was installing about 2metres of 50mm waste pipe and put a fall of 50mm per metre, when boss looked he said he would of made the drop shallower. I looked it up in JTL book and it states you can have a drop of between 18-90mm per metre on 50mm waste pipe and was just wondering what your thoughts on this are? What are your preferences of fall you put on waste pipe and also do you agree with the JTL book of 18-90mm fall?

Just after some more experienced views

thanks

tell your gaffer,if thats all he can pull you on he needs a busier life

 

[Gas]

Look up the slope gradient, you done it wrong.