Most of the leak calls we get don't come in September. They come in late November through February, right when the atmospheric rivers start stacking up off the Pacific and dumping five inches of rain on us in 36 hours. By then it's too late to prep. The small stuff you could have caught in October (a lifted shingle edge, a bit of cracked caulk around a vent, a gutter full of fir needles) has turned into water in the attic and a brown stain on the living room ceiling.
Fall prep in Seattle isn't complicated. It's just a handful of things that actually matter, done at the right time. Here's how we walk a house before the rain really sets in.
**Start with the gutters.** If you live under firs or cedars, once in early October isn't enough. Those needles keep dropping through November, and a clean gutter on Halloween can be half-packed by Thanksgiving. We tell homeowners with heavy tree cover to clear them twice, once in mid-October and again in late November. Pay attention to the downspouts too. A gutter that looks clean from the ladder can still be backed up at the elbow, and you won't know until water is sheeting over the edge during the first real storm.
**Walk the perimeter and look up.** You don't have to get on the roof for this part. From the ground, scan the ridge line, the valleys where two slopes meet, and anywhere a pipe or vent pokes through. You're looking for anything that isn't lying flat. Lifted tabs, a ridge cap that's shifted, a bent piece of flashing at the chimney base. Those are the spots water is going to find first when the wind drives rain sideways. If something looks off, get a pro up there before the weather turns. Our roof inspection service is cheap insurance when you're not sure what you're looking at.
**Check the valleys and flashing.** Valleys take more water than any other part of the roof because both slopes funnel into them. If there's debris packed in (fir needles love valleys), it dams up and pushes water sideways under the shingles. Clean them out. While you're at it, look at the flashing around the chimney and skylights. Cracked caulk or a separation at the counter-flashing is one of the most common leak sources we see in older Seattle homes. It's a cheap fix in October, an expensive one in January.
**Do a moss check, but plan, don't treat.** Fall isn't the right time to kill moss. The product needs dry weather to work, and we don't get that consistently after October. What you want to do now is note where it's growing, especially on the north slopes and under overhanging branches, and plan for a treatment in the spring. If you want the full breakdown on why moss is such a problem up here and how we actually handle it, we wrote a whole post on that: why Seattle roofs grow moss and what to do about it.
**Look for lifted shingles and missing tabs.** Summer heat softens asphalt, and sometimes shingles that were cooked all July will lift at the edges once they cool back down. A quick visual sweep from the ground with binoculars will tell you if you've got any edges flagging in the breeze. That's the kind of thing that gets ripped clean off in the first 40 mph gust, and once a tab is gone, water has a direct line to the underlayment. If you see anything hanging, don't wait. Small repairs are always cheaper than the leak that follows.
**Inspect from the inside too.** Grab a flashlight and go up into the attic on a dry day. You're looking for three things. Dark staining on the underside of the sheathing (that's old moisture). Soft spots or sagging (that's active damage). And any pinpricks of daylight you can see, especially near penetrations. If you find any of those, you've already got a problem that's only going to get worse once the rain comes.
**What can wait until spring, what can't.** Honestly, most of a moss treatment can wait. So can cosmetic stuff like streaking on the shingles or gutters that look ugly but still drain. What can't wait is anything with active water movement: a crack you can see daylight through, a flashing that's visibly separated, a soft spot in the deck, a gutter that overflows onto the fascia. Those get fixed now or they cost you a lot more later.
If you'd rather not mess with any of it, that's fair. Our maintenance program folds the annual walk into a scheduled visit so you don't have to think about it. We also bundle a soft washing treatment with most plans come spring. Homeowners around Seattle and the east side of the lake have been on these plans for years, and they're the ones who aren't calling us in a panic on the first wet weekend of December.
One last thing. If a serious windstorm rolls through before you get to any of this, a lot of the prep becomes moot and you're into a different conversation. We wrote a companion piece on exactly that: what to check after a Puget Sound windstorm. Worth keeping bookmarked.
Questions or want us to take a look before the weather turns? Get in touch and we'll get on the schedule.
