Soil pipe depth etc.

[festive]

Okay feel free to point me to the regs, i google'd for this couldn't find it.
We are moving our bathroom to one of the bedrooms. Soil pipe needs to come out of side of bungalow 90deg left (IC there i guess?) and then 45deg to hook up with soil pipe at existing IC at front/centre of garden.

What's the regs for the 'fall' of pipe height to existing pipe. I am getting a builder in to help me, just would like to know the facts myself as i want to start digging shortly. I live in Dorset if it makes any difference.

TIA

 

[noseall]

sewer pipes need a fall of 1 in 40.

in other words if they travel 4 metres they need to fall by 100mm.

the drains need a frost covering of about 300-400mm. but i've seen them shallower with no ill effects.

the drain pipes will need surrounding in pea gravel.

i.c. pots or chambers need to sit on a bed of concrete, usually 100mm thick.