[quote=“pats”]We are getting ready to replace our roof and a friend looking at the gutters said we need more downspouts. Any rule of thumb on how many downspouts should be used per foot of gutter. what about problems with gutters that seem flat (no pitch away from the roof)
Roof itself is a 4/12 pitch.
Anyone know much about “leaf-guard” gutters? Good/ Bad?
Yes, there is a method for calculating the size and quantity of downspouts needed to drain your roof properly. First, I would need to know the square footage of the roof area(s) being drained, and that includes any other roofs that drain onto the roof area where the gutters are mounted. Next, I would need to know the closest large city, so I can look into the 100-year rain storm totals. I also need to know what size gutters are installed on the building, and then I could give you a square inch total of downspouts needed. To make it easier, I also would like to know if you are using round or rectangular downspouts, and what the current size of those downspouts are.