2026-03-21 7 min read
If you live in Mountain View. especially in neighborhoods like Rex Manor, Monta Loma, or Cuesta Park. there's a good chance your garage door's weatherstripping is working harder than you realize. And there's an even better chance it's quietly failing.
Mountain View sits in the heart of Silicon Valley with a climate that feels mild on the surface. But weatherstripping doesn't get a break just because temperatures rarely drop below freezing. The real threat here is persistent moisture. Winters bring concentrated rainfall. February alone averages around 4 inches of precipitation. and the Bay Area's coastal fog rolls in with high relative humidity that hovers above 70% for much of the year. That moisture is relentless on rubber and vinyl seals.
In drier inland climates, garage door seals might last a decade without much attention. Here in Mountain View, the calculus is different. The combination of seasonal rain, fog-driven humidity, and UV exposure during our long dry summers creates a cycle that accelerates seal deterioration.
Fog, humidity, and coastal air break down rubber and vinyl faster than in dry climates. meaning the right materials really matter when you're replacing seals. Many of the older ranch-style homes built in the 1950s and 1960s that are common in Rex Manor and Monta Loma still have their original door frames and concrete thresholds. Uneven or aged concrete surfaces accelerate compression wear on the bottom seal every single time the door cycles. If your home is one of these classic mid-century properties. and there are thousands of them in Mountain View. your bottom seal may be compressing against a surface that's been shifting and settling for 60-plus years.
And then there's UV damage. During Mountain View's long, arid summers, south-facing garage doors get significant sun exposure. Sunlight degrades rubber and vinyl weatherstripping over time, causing the material to become brittle and crack. even when it isn't raining.
Bottom seal (astragal): This is the rubber strip along the base of the door. It compresses against the floor with every open/close cycle. easily 1,500 or more times per year. It's the most commonly damaged seal, and the first thing to check after a rainy season.
Side seals (jamb seals): These run vertically along both sides of the door frame and close the gap between the door panel edges and the frame. Look for visible separation or flattening.
Top seal: The horizontal seal at the top of the door. Often overlooked, but important for keeping out wind-driven rain during winter storms.
Threshold seal: A strip mounted to the garage floor itself rather than the door. Particularly valuable in Mountain View homes where the driveway slopes slightly toward the garage. a common characteristic of older properties.
A quick way to check all of them: on a bright day, close your garage door and look for daylight showing along the bottom, sides, or top. If you can see light, you've got gaps that are letting in moisture, pests, and air.
Gaps in your seals aren't just a weather problem. they're a money problem. When outside air infiltrates freely, your garage temperature swings, and if your garage is attached to your home (as most are in Mountain View's single-family neighborhoods), that affects your heating and cooling costs too. Sealing gaps helps maintain stable temperatures and reduces energy costs directly.
There's also the pest issue. Tiny openings around your garage door serve as entry points for ants, rodents, and other pests. a real concern in the Bay Area. Once inside, pests can damage wiring, insulation, and anything you're storing. For Mountain View homeowners who use their garage as a home office or workshop. increasingly common in this tech-forward city. that's a serious concern.
Finally, water intrusion near the base of the door can damage your garage floor, stored belongings, and even the bottom panel of the door itself over time. For routine care tips that go beyond weatherstripping, it's worth building a complete maintenance habit.
Here are the signs that your seals need attention:
- Visible daylight along the bottom, sides, or top of a closed door - Water puddles inside the garage near the door after winter rain - Leaves or debris blowing in under the door - Weatherstripping that feels stiff or brittle rather than flexible when you squeeze it - Increased energy bills without a change in your usage habits
Because weatherstripping deteriorates slowly, many homeowners adapt to the gradual changes without realizing how much protection they've lost. Inspecting your seals at least twice per year. ideally before the rainy season in October and again in spring. catches problems before they escalate.
Not all weatherstripping is equal, and in a Bay Area climate, material selection matters. EPDM rubber is a synthetic option designed to withstand UV exposure and resist cracking over time. it retains flexibility in ways natural rubber doesn't, making it a solid choice for bottom and side seals. Marine-grade vinyl is another good option for top and side seals, with strong resistance to moisture and UV.
For homes near the Bayfront or Shoreline areas of Mountain View where salt air is more of a factor, material selection becomes even more important. Standard vinyl seals may degrade noticeably faster in those conditions.
If you're not sure what material is currently on your door or what to replace it with, our team at Garage Door Mountain View can assess the situation and recommend the right fit for your specific door and climate exposure. Visit our services page to see what's covered.
Q: How often should I replace my garage door weatherstripping in Mountain View? A: In the Bay Area's humid, fog-affected climate, plan to inspect seals twice a year and expect to replace the bottom seal every 3,5 years under normal use. South-facing doors or those near the Shoreline may need attention sooner due to UV and moisture exposure.
Q: Can I replace garage door weatherstripping myself? A: Bottom seal replacement is a manageable DIY project if your retainer track is in good shape. you remove the old seal, clean the channel, and slide the new seal in. Side and top seals are more involved. If your door frame is older or the concrete threshold is uneven, a professional assessment will save you time and ensure a proper seal.
Q: Does weatherstripping affect my garage door's operation? A: A worn or incorrectly installed bottom seal can add friction and cause sluggish door movement over time. If you've noticed your door moving slower than usual, deteriorated seals may be a contributing factor alongside spring tension and lubrication issues. Check out our guide on identifying failing garage door springs to rule out other causes.