If you’re feeling a draft through your garage, spotting water puddles beneath the door after a storm, or noticing more pests finding their way in, your garage door might have gaps. It’s a common issue, especially with seasonal weather shifts in Portland, but fixing it doesn’t have to be a mystery.

At PDX Garage Door, we’ve helped homeowners all across the Portland area deal with these exact problems. In this guide, we’ll walk you through how to seal garage door gaps effectively, what causes them in the first place, and when you might want to call in a professional.

Why Do Garage Door Gaps Happen?

Before jumping into sealing methods, it helps to understand why garage door gaps appear. Knowing the cause can help you pick the best solution.

Common Causes of Garage Door Gaps

• Normal wear and tear — Garage door seals degrade over time due to use, weather, and aging materials.
• Shifting foundations — If your home has settled over the years, your garage floor may no longer be level.
• Incorrect installation — Poorly aligned tracks or panels can leave unintended spaces.
• Warped or damaged doors — Wood doors may bend due to moisture, while dents in metal doors can cause spaces at the edges.
• Weather changes — In Portland, wet winters and dry summers can cause materials to expand and contract.

Identifying Where the Gaps Are

First things first: find the problem areas. Here’s a simple step-by-step process.

Step 1: Turn off the garage lights

Grab a flashlight and stand inside your garage at night with the lights off. Have someone stand outside and slowly circle the door with a flashlight. If you see beams of light coming through, you’ve located a gap.

Step 2: Check all four edges

Garage door gaps can appear in several places:

• Bottom gap — The most common, usually due to worn or missing bottom seals.
• Side gaps — Often caused by bent tracks or shrinking weather stripping.
• Top gap — May result from uneven mounting of the door or settling of the house.
• Between panels — Older doors with worn joints can allow air and light through.

How to Seal Bottom Garage Door Gaps

This is the most straightforward gap to fix, and one of the most important. A loose or missing bottom seal can let in cold air, bugs, water, and even rodents.

Option 1: Replace the Bottom Seal

Most garage doors use a rubber “T-style” or “bulb-style” seal that slides into a track on the bottom of the door. What you’ll need:

• New garage door bottom seal
• Utility knife or scissors
• Flathead screwdriver
• Spray lubricant (like WD-40)

Steps:

1. Lift the door fully and clamp it in place for safety.
2. Remove the old seal by sliding it out of the track (you may need to cut it if it’s stuck).
3. Clean the track of any debris or buildup.
4. Spray a bit of lubricant into the track.
5. Feed in the new seal from one end, being careful to keep it centered.
6. Cut off any excess once the seal is installed.

Option 2: Install a Threshold Seal

Not the same as a door seal—this attaches to the concrete floor instead, creating a raised barrier the door presses against when closed.

Pros:

• Great for uneven floors
• Helps keep out water and pests

Cons:

• Requires adhesive and careful alignment
• May need temporary door adjustment

Sealing Garage Door Side Gaps

Side gaps can make your garage feel like a wind tunnel in the winter. The fix usually involves applying or replacing weather stripping.

Steps to Install Side Weather Stripping:

1. Measure the height of the garage door.
2. Purchase weather stripping (usually vinyl or rubber with a wood or metal backing).
3. With the door closed, press the stripping against the side so that it lightly touches the edge of the door.
4. Use nails or screws to secure the seal to the frame.
5. Repeat on both sides of the doorframe.

Be careful not to compress the seal too much or you could cause friction when the door opens and closes.

Sealing the Top of the Garage Door

Top gaps are less common but still a big issue if heat is escaping or rain is finding its way in.

Solutions:

• Top weather seal — Similar to side stripping, this mounts to the top trim board.
• Adjust tracks — Only if you’re experienced or with the help of a technician. Sometimes, the door isn’t fully reaching the top due to misalignment.

Fixing Gaps Between Garage Door Panels

Gaps between the panels (sections of the door itself) can be tricky and are more of an issue with older or worn doors.

What Can You Do?

• Apply garage door panel seals — Foam or rubber spacers that go between door sections to close small gaps.
• Lubricate and align hinges — Sometimes, cleaning and tightening sectional hinges can help close the space.
• Panel replacement — For extensive damage, you might need to replace the section entirely.

If your garage door is old and has multiple panel gaps, it may be more cost-effective to consider a full door replacement—something we at PDX Garage Door can help with.

How to Seal Garage Door Gaps on an Uneven Floor

In Portland, sloped driveways and settled foundations make uneven garage floors fairly common. Here are a few ways to close gaps caused by an uneven surface.

Best Solutions for Uneven Floors

Problem	Recommended Fix
Small gaps (under ½ inch)	Flexible rubber bottom seal
Moderate gaps (½ to 1 inch)	Combination of threshold seal + bottom seal
Large gaps (over 1 inch)	Adjustable bottom seal or garage door retainer

If you’re not sure what you’re dealing with, don’t guess—give us a call and we can look at your specific situation.

What Materials Should You Use to Seal Garage Door Gaps?

Not all seals are created equal. Picking the right material helps ensure durability and performance throughout Portland’s rainy seasons and dry summers.

Common Seal Materials

• Rubber — Flexible and weather-resistant; best all-around material.
• Vinyl — Affordable and durable, though less flexible in freezing temps.
• Silicone — Highly flexible and long-lasting; ideal for dramatic temperature swings.
• Foam — Good for temporary fixes, not suitable for outdoor-facing gaps.

When to Call a Professional

DIY sealing can work wonders, but sometimes the problem is beyond a quick fix. You might need a professional if:

• The floor slope is extreme or the door doesn’t sit level.
• There are gaps in the door structure itself.
• Your current door isn’t insulated and weather sealing isn’t helping much.
• You’re experiencing consistent pest invasions or water leaks despite sealing.

At PDX Garage Door, we’re more than happy to take a look. We’ll inspect your door, layout, and sealing options—and help find a long-term solution.

Frequently Asked Questions

Can sealing my garage door really help with heating bills?

Yes. Even if your garage isn’t heated, cold air sneaking through the garage affects adjoining rooms—sealing the gaps reduces drafts, helping your home stay warmer with less energy use.

How often should I replace garage door seals?

On average, every 2–3 years. But in Portland’s wet climate, you might need to replace seals sooner, especially if they show cracking, flattening, or mold growth.

Can I install garage door seals myself?

Definitely. With the right tools and a bit of patience, many homeowners successfully install seals. For more complex issues (like uneven floors), a professional install makes more sense.

Final Thoughts: A Sealed Garage is a Healthier Garage

Sealing garage door gaps isn’t just about comfort—it’s about protecting your home. Cold air, rodents, water, and unwanted insects can all slip in through even small openings.

If you’re noticing drafts or seeing light under your garage door, don’t wait for it to become a bigger problem. Start with simple fixes like weather stripping and bottom seals. Test your efforts, and if the issue persists, we’re here to help.

At PDX Garage Door, we specialize in making sure your garage works the way it should. Whether you need a quick seal replacement or a full inspection, our Portland-based team is just around the corner.

Let’s keep your garage sealed, safe, and secure—reach out today or follow our blog for more helpful DIY tips.