Due to the structure of the roof, the water from several planes goes into one spot of the gutter, which causes severe overshooting problem even with clean gutter, as one can tell from the water marks on the siding. The proposal I got is to replace the related gutter from 5” to 6”, downspout from 2x3 to 3x4, and add a downspout from the upper gutter to the lower one. Is it enough to solve the issue? Any other measures like diverter or splash guard needed?

I would like to confirm its effectiveness before moving forward, because I’m not living there, and cannot do trial and error. Is there any way to test it by simulating a heavy rain? A garden hose won’t bring enough water to the roof.

enter image description here

  • My opinion is to get rid of all the upper gutters, The short little ones under the tiny wing roofs are especially useless. In a hard rain the water may gush over the lower gutter. ( I would get rid of that too) Hard rains are for short periods. I prefer to have the water shed from my roof where it can be managed on the ground and will cause less damage.
    – RMDman
    Commented Aug 13, 2023 at 19:09
  • 2
    Where does the water from the upper gutter go - does it dump on the roof to the right and then run down to the problem area? It might be helpful to add a downspout to the upper gutter to discharge directly into the lower gutter.
    – Mark
    Commented Aug 14, 2023 at 2:59
  • 1
    Is the short zigzag or two short gutters directly above the red circle connected to a downspout? If not, then that whole center/left section of roof is contributing to your issue (which I think is what you are saying). Does the upper gutter section just overflow along its length, so you may also have water coming directly down from it and not into the lower roof slope?
    – Armand
    Commented Aug 14, 2023 at 3:22
  • 1
    @Huesmann The upper gutter has no downspout or right end cap for now, and the water comes out at the right end to the roof.
    – bobby_yan
    Commented Aug 15, 2023 at 15:54
  • 1
    Oh, that's definitely not good. As to the two suggestions you've received, obviously I'm partial to mine. I can't imagine how you'd get a dedicated downspout to the ground, without all kinds of bends and such.
    – Huesmann
    Commented Aug 16, 2023 at 11:55


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.