I will be moving various bits of soil piping around and have drawn a blank on fall rates. From a look, old cast iron pipes look to have a generally steeper fall than modern (smooth) plastic piping [which makes sense]. Also, soil piping seems to come with either 2.5 degree or 22.5 degree branch adaptors. What are the regs / practice? Is it
Thanks,
Mark
I looked this up the other day and found reference to it being from 1:40 to 1:80
LJ
The figures 18 - 90mm fall per metre run come to mind - going down to 9mm if you have more than 1 bog connected?, which going back to the original question means that 22.5 deg is too steep
Jon
IIRC building regs say the fall should be between 18 and 90mm per meter.
Have a look at approved document H:
That's between 1 and 5 degrees in real money!
Thats is, if its too steep the water runs away, and the solids have no water to travel with.
1 in 0 (vertical) is also allowed.Rick
I had 1:60 to 1:110 s being in te range for outside work.
I'd say that 1:60 lies within all our estimates,so should be adopted.
or 1:11 to 1:50 in ratios
All "90 degree" fittings are 87.5 degrees to allow for a fall. The required fall depends on a lot of things (content, number of inlets etc)
Have a look at the Osma/Wavin site, in particular:
Have something to add? Share your thoughts — no account required.
Ask the community — no account required