another gutter question

[Tim Lamb]

Is there a recommendation for the maximum roof area to be drained by 4" plastic gutter?

Building regulations were a distant dream when my Victorian barn was built and the twin down pipes discharge through shoes onto the narrow strip of verge next to the lane. There has been some local subsidence of the foundations as a result.

I am currently building a single story *end* extension and will make provision to pipe collected rainwater to an existing surface water system. However, underground piping from the original down pipes is not practicable.

Could I route the barn water along the new gutter without annoying building control? The total area drained would be 35m2 in plan.

regards

[RubberBiker]

I think at 35m2 you're probably ok with 4" gutter, depending on roof pitch etc. Detailed info and tables in Part H of building regs.

[mogga]

You could ring them and ask them? :)

[Rob G]

I looked into this very recently but blow me I cannot find the websites I found a week ago, but they are there. I thought the pavingexpert site had details but seemingly not. It might well have been one of the suppliers of guttering that was helpful.

You will need to hunt the details up with an appropriate search. One of the factors is whether the guttering has a fall on it not - factor of about 2:1 !! If my memory is correct something like 60m^2 if there is a fall. I know that my 35m^2 is well within spec for the change in direction I want to do but I will have to adjust the slope. I will however have to do a 1m^3 rainwater SUDS tank.

Rob

I would be chary about involving the BCO as he will insist on you putting in an appropriate soak away.

[Tim Lamb]

In message , RubberBiker writes

Umm... I looked after posting! OK to combine two sets of guttering with a drop pipe and a shoe. For significant volumes they want some sort of discharge pipe. I guess a bend and a short length of horizontal pipe will do. Didn't find any tables. Perhaps they are in the old version.

Google gave me a calculator and a list of rainfalls for various Australian cities.

regards

[Tim Lamb]

In message , mogga writes

St. Albans D.C. has discovered messaging services:-(

regards

[Tim Lamb]

In message , Rob G writes

I really should have Googled this before posting. There are numerous sites offering calculators.

Sorry folks.

regards