How to Fit an Up and Over Garage Door Seal

Up and over garage doors remain one of the most popular types in the UK. They are simple to use, affordable, and reliable, but like all garage doors they are rarely a perfect fit against the ground. Small gaps almost always exist along the bottom edge, allowing water, draughts, dust, and pests to find their way inside.

A garage door seal solves this problem by filling those gaps, creating a barrier that improves comfort, cleanliness, and protection. Fitting a seal is one of the easiest upgrades you can make, but many homeowners are unsure where to start.

This article provides a detailed step by step guide to fitting an up and over garage door seal. It explains the tools you will need, how to measure correctly, how to prepare the surface, and how to install and test the seal for the best results.

Why Fitting a Seal Matters

Before looking at the steps, it is worth understanding why seals are so important.

Without a seal, water can seep into the garage during heavy rain, leading to damp floors and potential damage to vehicles and stored items. Draughts make the space colder, which can affect comfort in adjoining rooms. Dust, leaves, and pests also find their way in through gaps, making the garage less pleasant to use.

Fitting a seal solves all of these issues quickly and cost effectively. A good seal blocks water, keeps out draughts, and makes the garage easier to keep clean.

Choosing the Right Seal

Up and over garage doors usually require a bottom seal or a threshold seal, and in some cases a combination of both.

A bottom rubber seal attaches directly to the underside of the door, compressing against the floor when the door closes. Some doors have built in channels for seals, while others require screw on strips.

A threshold seal is fixed to the garage floor, creating a raised ridge that the door closes against. This type is especially useful for uneven floors or driveways that slope towards the garage.

Side and top weatherstripping can also be added to improve insulation around the frame.

Before buying, measure the width of your door carefully and decide whether you need a bottom seal, threshold seal, or both.

Tools and Materials Needed

Having the right tools makes the job smoother and quicker. You will need:

• A steel tape measure for accurate measurements
• A pencil or marker for marking positions
• A utility knife or heavy duty scissors for cutting rubber seals
• A fine toothed saw for cutting threshold seals
• A straight edge or ruler for guiding cuts
• A caulking gun if adhesive is supplied in cartridges
• Mild detergent and water for cleaning surfaces
• Safety gloves to protect your hands

Most seal kits include the seal itself and, in the case of threshold seals, the adhesive required.

Step 1: Measure Accurately

The first step is accurate measurement. Measure the full width of your garage door panel at the base. For threshold seals, measure the width of the garage opening at floor level. Record your measurement to the nearest millimetre.

If your door has a channel for a seal, measure its width and depth to ensure the new seal will fit. Never rely on the old seal as a template, as it may have stretched or shrunk over time.

Step 2: Clean and Prepare the Surfaces

Preparation is key to a successful installation. For bottom seals, clean the underside of the door with mild detergent and water to remove grease, dirt, and dust. For threshold seals, sweep the garage floor thoroughly, then wash and allow it to dry completely. Adhesive will not bond to damp or dirty surfaces.

If there are cracks or uneven areas in the floor, repair them if possible before fitting the seal. This ensures a tighter fit and longer lasting result.

Step 3: Cut the Seal to Size

Lay the seal flat and mark the correct length with a pencil or marker. Cut carefully with the appropriate tool. For rubber or vinyl strips, use a sharp utility knife or scissors. For threshold seals, use a fine toothed saw to achieve a clean cut.

It is better to cut slightly longer and trim back for precision than to cut too short and leave a gap.

Step 4: Position the Seal

Before fixing, place the seal in position to check alignment. For bottom seals, slide the strip into the channel or hold it against the base of the door. For threshold seals, close the door gently and place the strip on the floor to see where it meets the door edge.

This dry fit allows you to confirm the seal is the right size and that the door closes against it correctly.

Step 5: Fix the Seal

The method of fixing depends on the type of seal.

For bottom rubber seals in a channel, slide the strip carefully into place. This may take patience, particularly with thicker seals, but once inserted it provides a secure fit.

For screw on bottom seals, align the strip against the base of the door and fix with screws provided, ensuring even spacing for a tight hold.

For threshold seals, mark the position on the floor, then apply adhesive in a continuous bead along the marked line. Press the seal down firmly into the adhesive. Close the door to check alignment and make adjustments while the adhesive is still workable.

Step 6: Allow Adhesive to Cure

If fitting a threshold seal, allow the adhesive to cure fully before using the garage. Most manufacturers recommend between 12 and 24 hours. Do not drive over the seal or expose it to water during this time, as this may weaken the bond.

Step 7: Test the Door and Seal

Once installed, test the door several times. Open and close it to ensure it moves smoothly and compresses evenly against the seal. Check from inside the garage for any visible gaps or daylight at the base.

If gaps remain, adjust the seal or consider adding a secondary threshold or weatherstripping.

Step 8: Maintain the Seal

Installation is not the end of the job. Regular maintenance keeps the seal working effectively.

Clean seals every few months with mild soap and water to remove dirt. Apply a silicone based spray to rubber seals once or twice a year to keep them flexible. Inspect seals for cracks, brittleness, or signs of wear, and replace promptly when needed.

Time Required

For most up and over doors, fitting a seal takes between 30 minutes and two hours depending on type and experience. Threshold seals require longer due to adhesive curing time. Allow at least a full day before normal use if fitting a threshold.

Common Mistakes to Avoid

Cutting the seal too short is a frequent mistake. Always measure carefully and cut slightly longer than required.

Fitting on dirty or damp surfaces is another error. Adhesive will not bond properly unless the floor is clean and dry.

Choosing the wrong thickness of seal can also cause problems, preventing the door from closing or locking. Always check the size of the gap before buying.

Benefits of a Well Fitted Seal

Once fitted correctly, a seal provides long lasting protection. It blocks water, draughts, dust, and pests, keeping the garage dry and more comfortable. It also supports energy efficiency by preventing cold air from reaching adjoining rooms.

Financially, a small investment of time and money in fitting a seal saves on heating costs and prevents expensive repairs caused by water damage. Environmentally, seals reduce wasted energy and cut down on carbon emissions.

Conclusion

Fitting an up and over garage door seal is a simple project that delivers big benefits. With accurate measurement, careful preparation, and patient installation, most homeowners can complete the job in under two hours. Threshold seals take longer due to adhesive curing, but provide a strong and lasting barrier against water and draughts.

By following this step by step guide, you can ensure your seal is the right size, fitted securely, and working effectively. Regular cleaning and maintenance then keep it performing for years, protecting your garage and supporting the efficiency of your home.