What fall does a soil pipe need?
For a 100mm foul drain the usual fall is around 1 in 40 to 1 in 80. A common working figure is 1 in 40 for short runs, easing towards 1 in 80 on longer runs to avoid the solids being left behind.
Foul drainage needs enough fall to self clean without running so fast that liquid outruns solids. For 100mm pipe a fall between 1 in 40 and 1 in 80 is typical, with 1 in 40 often used on shorter branches. Always follow the current Building Regulations and the specifics of the job.
Otis can talk a customer through the parts for the run, keep the fittings compatible and price the lot, while pointing them to the right guidance for their specific installation.
General guidance for the trade. Always follow current Building Regulations, manufacturer instructions and the specifics of the job.
See what Otis would capture for you
Book a strategic call and we will model it against your own numbers.