How to Seal Drafty Doors Before Cooler Weather Arrives

A drafty door is one of the most wasteful energy problems in a Winnipeg home — and one of the easiest to fix before winter sets in. Here's how to diagnose the problem and seal it up properly, with guidance on when a repair is enough and when replacement is the smarter call.

How to Find the Draft

On a cold or windy day, hold your hand slowly around the perimeter of your exterior door — along the sides, top, and especially the bottom. You'll feel any air movement immediately. For a more thorough test, light a stick of incense and hold it near the frame: smoke that wavers indicates airflow.

Another method: on a sunny day, have someone stand outside shining a flashlight around the door perimeter while you observe from inside. Light gaps are draft gaps.

Weatherstripping: The First Fix

Most door drafts come from failed or compressed weatherstripping — the foam, rubber, or vinyl seal that runs around the door frame. Weatherstripping compresses over years of use and loses its ability to form a complete seal.

Replacing weatherstripping is a straightforward DIY project:

1. Remove the old weatherstripping (usually peels or pries off).
2. Clean the channel with isopropyl alcohol.
3. Measure and cut the new material, ensuring complete coverage at all corners.
4. Press or nail the new strip firmly into place.

Use compression-type weatherstripping (foam with adhesive backing) for light drafts, or V-strip (tension seal) for gaps where the door flexes away from the frame under wind pressure.

Door Sweep and Threshold

The bottom of the door is responsible for the biggest drafts. There are two components:

• Door sweep — attached to the bottom of the door itself; brushes or seals against the threshold.
• Threshold seal — the rubber or vinyl insert in the metal threshold on the floor. These compress over time and should be replaced when they no longer spring back to shape.

Both are available at hardware stores and install with basic tools. Replace both at the same time for a complete seal.

Caulking Around the Frame

Where the door frame meets the exterior siding, caulking prevents air from infiltrating behind the frame. Check this seal every fall and re-apply paintable exterior caulk anywhere you see gaps, cracks, or shrinkage. This is a 30-minute job that makes a meaningful difference.

When to Replace Rather Than Repair

Weatherstripping, sweeps, and caulking can fix surface-level sealing issues. But if your door:

• Is warped and no longer sits square in the frame
• Has a rotting or water-damaged frame
• Lets in noticeable cold through the door surface itself (poor insulation)
• Is more than 20 years old with failing hardware

…then repair is a temporary measure. A modern insulated steel or fibreglass entry door will outperform any amount of weatherstripping on an aging door — and come with warranties that protect your investment for decades. Our team is happy to help you evaluate whether repair or replacement makes more sense for your situation.