Downspout and valley sizing
Downspout and valley sizing
(OP)
First post. I need to verify sizing of roof valley gutter and downspouts required. C=0.99 A=1(acres) I= 8.0 in/hr. I used the circular weir formula Q=CA(2gh)^0.5
I am not aware of any COde Requirment for this and am not sure that Q=CIA is applicable for roofing systems (although it would seem to apply).
Comments welcome.
THX
rhb
I am not aware of any COde Requirment for this and am not sure that Q=CIA is applicable for roofing systems (although it would seem to apply).
Comments welcome.
THX
rhb





RE: Downspout and valley sizing
RE: Downspout and valley sizing
What year event would normally be used (if there is such a thing as normal)?
I also found an old SBC (southern building code) with sizing data. It looks as though the sbc uses a 10 yr event (100 yr 15 min precipitation curves) with an in/hr number of 8". 8" is what I got using ifd curve data for my state and county with a tc of 15minutes. Are these the same things?
THX for comments
RHB
RE: Downspout and valley sizing
Make sure you are looking at the applicable code.