Feasibility changing downpipe location on guttering

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Am considering moving the guttering downpipe out the back of our property as indicated by the red line in the attached image.

IMG_20210928_100527039 (1).jpg


It will be neater than shown ;)

I know I will have to contact building control RE adding in new gully and connecting in to the existing chamber which is surface water not foul.

I cannot think of a reason why this isn't feasible, the gradient and position of the downpipe would obviously need to change.

If you think I am wrong and this change isn't possible or could/would be problematic please let me know?
 
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depending on the location of the lawn (if any) it may be easier to put a soakaway in.

Only question I have is - why?
 
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The existing drain goes under extension and keeps getting blocked with moss.

There is a nearby lawn, how much lawn space would I need for a soakaway and how near to the boundary etc. must it be?
 

CBW

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What about divertering into the garage one, or is that not possible?
 
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The existing drain goes under extension and keeps getting blocked with moss.

There is a nearby lawn, how much lawn space would I need for a soakaway and how near to the boundary etc. must it be?

You need to calculate it. But roughly looking at the photo, I would say 0.8m3 would do it (40M2 roof area). Might be less.

Dig a hole roughly 1m3 (maybe a bit deeper to allow flow depth. Fill it with either a soakaway kit or cut up soil pipes, some pea shingle and put the grass and soil back on after.
 
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Didn't consider either option thanks both.

What about divertering into the garage one, or is that not possible?

Didn't even consider this garage is stepped back 2m though, is this allowed and what limitations would there be, am assuming the capacity of the gully (the garage is massive)?

You need to calculate it. But roughly looking at the photo, I would say 0.8m3 would do it (40M2 roof area). Might be less.

Dig a hole roughly 1m3 (maybe a bit deeper to allow flow depth. Fill it with either a soakaway kit or cut up soil pipes, some pea shingle and put the grass and soil back on after.

In terms of roof area do I need to work out somehow with the pitch in mind, or can I simply measure from the ground and calculate? If the pitch is important can you point me in the right direction as to how to calculate? No idea of my roof pitch?
 
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I am no expert but surely a pitched roof on a 1M square block may have a greater surface area, but only collects 1M sq worth of rain?
Most rain comes pretty much straight down
 
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Yes pitch is a factor, but from the pictures it looks about 30%. so its only 30% on top. roughly you add on the pitch angle as a percentage.

It looked about 10m x 3m from the picture
 
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It may well be far easier to fit a Rainwater Gulley under the existing downpipe, (as long as you remember to clean it out as required), seems an awful lot of hassle for a bit of moss! Where does the water go currently? FloPlast Leaf/Debris Interceptor Gully - Black | Wickes.co.uk

If going down the Soakaway route, (I wouldn't bother if a surface water drain is readily available), you will need to do a percolation test first to determine the porosity of the soil and how big the soakaway needs to be.
 
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