Had a similar thing happen last summer—went flush on my own shed roof (I’m in upstate NY), and after a week of rain, there was this weird ghostly line on the fascia. Looked like a coffee stain. It faded out after a dry spell, but I did end up tacking on a scrap of EPDM under the edge just in case. Not sure if it was overkill, but hey, better safe than sorry... and it gave me an excuse to buy more sealant.
That ghostly line sounds familiar—seen it on a few properties after heavy rain, especially where the drip edge isn’t quite right or the fascia’s got a little warp. I wouldn’t call adding EPDM overkill at all. If anything, I’ve found that a little extra protection at the eaves saves headaches down the road. On one of my older duplexes, we had a similar stain show up after a stretch of wet weather. Turned out water was wicking back under the shingles because the overhang was just a hair too short. We ended up sliding some peel-and-stick membrane under there and it hasn’t come back since.
Funny thing is, I used to think those stains were just cosmetic, but after seeing what happens when moisture sits in the wrong spot for too long—especially in our freeze-thaw cycles—I’m more cautious now. Sometimes you don’t notice rot until you’re replacing trim boards and realize they’re soft as bread.
I get what you mean about “excuses” to buy more sealant... I swear half my garage is tubes of caulk and leftover flashing tape from jobs like this. It’s not always pretty work, but it keeps things dry.
When it comes to green roofs or any kind of new layer, I’d say double-checking all those edges is worth it, even if it feels like overkill at first. Water finds its way in the weirdest places, especially around transitions and corners. And once you’ve got plants up there, tracking down leaks gets trickier.
Curious if you noticed any difference in how fast that fascia dried out after adding the EPDM? Sometimes even a small patch changes how water runs off completely.
I’ve definitely seen that kind of staining linger a lot longer than folks expect, especially if the wood’s already absorbed some moisture. EPDM can make a noticeable difference, but sometimes it just redirects the water somewhere else if the slope or flashing isn’t quite right. Did you end up checking the soffit vents after the patch? I’ve run into cases where improved runoff actually led to condensation issues inside the eaves, which caught me off guard the first time. Curious if you had any venting tweaks after sealing things up.
I actually didn’t think to check the soffit vents right after sealing up, which might’ve been a rookie move. I did notice a bit more humidity in the attic later, though—maybe that’s related? Did you add extra venting, or just tweak what was already there? I’m still figuring out if I need to up my airflow or if it’ll balance out once things dry.
Yeah, humidity in the attic can definitely be tied to venting changes. When you seal things up, it’s easy to accidentally choke off airflow without realizing it—been there myself.
“Did you add extra venting, or just tweak what was already there?”
I actually ended up adding a couple of extra roof vents after I noticed condensation on the sheathing that first winter. The original setup just wasn’t cutting it once I tightened up the rest of the house. If your soffit vents are blocked or not pulling in enough air, you’ll see humidity spike, especially if you’ve got any gaps where warm air from the living space can sneak up.
I wouldn’t just wait and hope it balances out, honestly. Attic moisture can turn into mold or even rot pretty quick if left unchecked. I’d double-check that your soffits are clear (sometimes insulation shifts and blocks them), and maybe look at boosting ridge or gable venting if you’re still seeing high humidity after things dry out. It’s a pain but way easier than dealing with repairs down the line.
Curious—what kind of roof do you have? Some types vent easier than others.