Pan flashing guidance
We experienced an interior leak that we believe came from our pan flashing on our roof. I did a search and do not see articles here about proper install of roof pan flashing. Can you help? I want to ensure the roofers are following correct protocol when fixing this. Also, if you got water into your ceiling during a large ice/snow storm (unusual 12″ for us here in Kansas City), and you removed the ceiling, and now the soffits right there as well as the roof decking in the attic crawlspace right there are still showing as wet on the moisture meter almost 2 months later (and tend to increase by a couple % points each time it snows), how do you determine a) is this active moisture or a one-time event and b) is it for sure coming from the roof flashings? I’m attaching a photo of the complex area – you can see it has pan flashing, kickout flashing and step flashing. Not sure what our first steps here should be, and also if this is the right time of the year where we can even dig into the roof.
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That is one of those roof details that always leaks, makes me mad when I see it in a new build as it should always be avoided.
If the ceiling is open it is hard to see where the water comes from as the house air will tend to dump a lot of moisture into the roof space.
You can go up there with a garden hose and a couple of rags to plug the drain area and fill it up to see if it leaks.
If it is only from snow, you can put some snow melt rope up there and run it only to melt any buildup.
This may have been an ice dam induced leak, especially if this area faces nearly north. If an ice dam formed in the gutter, I would expect that leakage to come out of the soffits below. In fact, icicles hanging from the soffit vent and running down the siding under the gutter are two of the best indicators of ice dam failures, but you have to catch them in the act while the weather is still cold. I'm thinking that, if you got leakage inside the house, it is more likely that an ice dam formed behind the bump-out where the second floor wall bumps out from that little triangle of wall above it. That area is also fed water from the upper gutter, so an ice dam here could hold back a pretty big pond on the roof. The permanent fix for this is to strip the roof and siding above that bump-out and protect it all with ice&water shield, run at least a foot up the siding. 18" would be better. Or, if this is just an occasional thing and you don't feel like spending that much to fix it, Akos' suggestion is certainly worthwhile. Put a switch in the garage and run it only when you have ice/snow buildup.
Thank you, Peter. This side does face north. We may have had a small ice dam on the second story, but the story is a bit complicated. See, we DID have an ice dam on the south side of our home (not pictured here), and hired a company that uses steam to come remove it. That was successful. When the guy was here, we were uncertain about the ice dam on this north side, so we had him remove any ice and snow from the second story here as well. The problem is, in hindsight, he removed all that, and it came pouring down on the first floor while the flashings were iced over. Our guess is that some of that water entered the home where it normally would not.
The part that has us scratching our heads is that this all happened beginning of Jan, and the lumber inside the soffits as well as the decking on the roof right there in that location is still wet. And it seems to creep up in wetness each small snow we have. The roof decking there is very dark, indicating this is a recurring problem. But perhaps it only got "inside" that one time. But we still feel like we need to address it, as water shouldn't be getting in the soffits every time it rains or snows, right? Just unsure how far to go as far as digging into the roof, and if we are even in the right season to do that. We do have the ceiling that's been torn out covered in plastic/tape/staples to keep the cold air at bay. Oh, one more detail - when we had the remediators here to take out the ceiling, we did have them remove a portion of the wall on the second floor you reference in your comment (the bump out area). That is/was dry, but the exterior lumber has a water stain.