[Haggis]

Hi,

Just wondering if someone could let me know the maximum fall that can be used when installing rainwater pipework within a ceiling void (preferably to British Standards).

I'm currently co-ordinating the services on a job and have been using a fall of 1:100. I've never done drainage pipework before and like to know what is the normal fall used and what is that minimum fall that I can use!

As usual, the ceiling void is tiny and I'm struggling to get everything in!

Thanks for any help!

 

[mdshunk]

I know that in the US, roof stormwater conduits may be installed level, but they are normally installed with the normal DWV fall of 1/8 - 1/4 inch per foot. Just remember, the less fall you have, the heavier (much heavier) the pipework will be while conveying the rainwater. This can make a difference with respect to the support/strapping interval.