I've got two problems:

  1. The edge of my 2nd story roof does not protrude past the drip edge, which is causing water to track back up and under the metal panel. It's a shallow pitch, and the water has infiltrated what appears to be a rigid foam insulation. See pics below.

  2. The foam sits under the metal panels without underlayment or sheathing. I assume the decking is below the rigid foam. Shouldn't there be something between the metal panels and the foam insulation? Cathedral ceiling with no attic.

What's the right course of action here? Longer metal panels to sit over the drip edge? Install sheathing or underlayment below the metal?

Roof Line

Rigid Foam

Rigid Foam with Drip Edge

  • The foam is probably more for sound insulation than heat, some people do not like the pitter-patter of the rain hitting the metal roof. Will need to check the roof deck for rot, but lengthening the metal panels will be good. Might get by with strips of the same panel design than need for full longer panel replacement.
    – crip659
    Nov 22, 2023 at 20:01

1 Answer 1

  1. I like the idea of simply extending the roofing to overhang the drip edge. If you can find steel in the same profile it's a simple matter of slipping it underneath and installing new screws at the same locations. I'd overhang maybe 2 inches, but look into what the manufacturer considers a maximum. 3-4" might be better to prevent wind-driven rain intrusion.

  2. Steel roofing often rests solely on and spans across purlins, horizontal wooden slats which overlay the rafters. The fact that you have foam between the steel and the purlins or decking isn't itself a concern. Whether you need more stuff in your roof system depends on where you are and what the entire material stack looks like, along with what other problems you have.

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