Is this roof big enough to collect rainwater?

[dllive]

Hi all,

This is an odd question, but one I thought Id post before going to the trouble of fitting a water butt.

I want to fit a water butt to the corner of an outhouse so its kinda hidden from view. But - as you can see - the roof is fairly flat (which may not be an issue) and small. I know its a massively open-ended question, but is it a waste of time fitting a 200 litre water butt to this downpipe becuase it may never get full up? Or am I over-thinking this?

 

[rsgaz]

becuase it may never get full up?

You can work out how much rain you will get. You say you are a in Surrey, a quick google gives annual rainfall as 707mm (We'll use 700 for the sums)

If the roof is 3 metres by 4 metres, that's 3000*4000*700/1000000= 8400 litres

Those butt diverters don't divert all the rainwater when filling, so just half it for a more realistic answer of 4200 litres per year. Easily enough!

 

[Mottie]

I have a couple of 200litre water butts connected in series to the drain pipe from the roof of my 8’x6’ shed on my allotment as do many others over there. Okay, ALL the water goes into them but no problem filling those up. The ploy owner to my left has four of them collecting water from a 6’x4’ shed!

 

[JP_]

Will get a fair amount. I had a water butt on a small garage and that was always full.

 

[dllive]

Great - thanks all! Thats given me peace of mind.
(I wasnt sure Id get an answer to this esoteric question!)