This seems like a problem that shouldn't exist. House built in the 50's, and has two roof sections almost identical, but for the bump out they overlap(!?), and the bottom is closed in, which has resulted in the wood of the soffit becoming incredibly rotten.

Thankfully there is no interior water damage that I know about. Short of having more flashing installed when I inevitably have the roof replaced in the next 10 years or so, anything I can do in the short term to mitigate it?

I'm in Canada so have to deal with freezing temps, which makes me a little worried about a rain diverter like this, as I wouldn't want water damning up and freezing under the shingles.

Photos of the roof:

Roof overlap 1

Roof overlap 2


1 Answer 1


You don't need to wait to get your Roof completely redone to fix this issue as it should only require a single pack of shingles and some flashing to fix the issue.

While the vertical wall (from the Bump-out) is very short, it is still a Roof to Vertical wall intersection that requires the use of Step flashing to prevent water from entering.

Two additional steps that I am currently taking to prevent this issue in the future is

  1. Replacing the wall sheathing with a water resistant version (Zip Wall) and
  2. replacing the Soffit boards with PVC boards.

Here is a guide to Retrofitting Step Flashing: https://www.aconcordcarpenter.com/retrofitting-step-flashing.html

(No affiliation with any of the products discussed)

  • This looks like good advice. Please indicate whether you have any affiliation with the site you've linked.
    – FreeMan
    Commented Nov 2, 2023 at 13:12

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