What are the building regs for a new underground drain?

[FiscoKing]

Hi,

Just added a new soil stack to the side of my house (4 inch).

What are the regs for new underground soil pipes?

Depth of excavations?
Type & amount of gravel below & above the pipe?
Type of pipe?
Etc..

Any help appreciated.

Thanks.

 

[Richard C]

Log onto here:

http://www.planningportal.gov.uk/england/professionals/en/4000000000382.html

read & digest!

 

[noseall]

depth will depend upon existing drains and fall requirements to get to them.

i would try and establish a minimum of 300mm below ground or paving level, but this isn't always realistic.

ensure that you have 1:40 fall and you will be ok.

surround the pipe in pea gravel. this usually means a brick under the pipe at 3m intervals (plastic soil pipe) and then fill the void with a few inches of cover.

clay or plastic is acceptable and neither is (b.c.) preferred.

i always use plastic.

 

[FiscoKing]

Thanks for the info.

Will speak to TP tomorrow.

 

[Richard C]

Thanks for the info.

Will speak to TP tomorrow.

Don't forget, it needs to be inspected (fee involved) or you could create future problems for yourself. No big deal & I did a 10m one just yesterday. BC inspector arrived an hour early & caught us on the hop but she had a good look & wasn’t bothered; perhaps it was deliberate! Mini digger parked, big trench, only ½ the pipe run installed, pile of gravel on the drive for infill, stack & everything else up the line she schecked OK but not connected! "Do you want a test & witness I say" – “no” she says & off she went with a “cheerio boys, just let me know when you want the completion certificate & I'll come back & check. Am I happy!

 

[shockfreesince93]

300mm seems like a good place to start. Should this be increased if layed across driveway/parking area.

With regard to the 1:40 gradient, I was advised to keep it between 1:80 and 1:110 and that if I go any steeper I run the risk of liquids escaping too fast leaving the solids behind.

Would love to know if any of this is correct

Cheers

 

[theoldun]

In the days long ago when we used salt glazed collar pipes, 1in40 was the recognised fall, how ever since the introduction of smooth bored PVC-U flexible pipes the minimum fall is 1in80 providing that there is a WC close to the head of the line. If no WC close to the head then go 1in40 or 1in60 depending on invert levels required and then drop to 1in80 if required when picking up WC branch connection.
Whilst BC will not approve it is possible with high degree of workmanship to lay 100mm PVC-U at 1in120
It is a myth that 1in40 fall leaves the solids behind..
Would suggest that if going across vehicle access, increase your depth, 50mm shingle above pipe, then 100nn concrete over with expansion joint every 6000. Top up with MOT and surface finish.
Regards oldun

 

[noseall]

it is possible with high degree of workmanship to lay 100mm PVC-U at 1in120
It is a myth that 1in40 fall leaves the solids behind.

Agree with bells on regarding the above.

 

[shockfreesince93]

Thank you gentlemen. My friendly neighbourhood building inspector also agreed with bells on. Gold stars alround