Draft defense

How to seal garage doors: Keep the weather out and the savings in

Once you know how to seal garage doors, you’ll wish you had done it years ago. This is an easy DIY project that brings many benefits – including improved insulation, protection from the elements, and safety to name a few. Come and learn for yourself.

How to seal your garage door and why it’s important

The quickest way to seal garage door sides and top is to install weatherstripping. Weatherstripping is simply a flexible rubber or vinyl gasket that is attached to the garage door jamb. As a result, a seal forms when the garage door is closed, which is critical to protect your home against some extreme Canadian weather.

Weatherstripping can be attached with hand-driven nails, screws, or a pneumatic stapler. We’ll provide full instructions below. Although it’s a simple and inexpensive job, there are many benefits to sealing your garage door. It will:

  • seal out drafts, lowering your heating bill and making the garage more comfortable
  • keep out moisture and weather, protecting your home and vehicles
  • help prevent rodents and insects from entering your garage and home

How to seal garage door sides and top with weatherstripping

Let’s cover how to install weatherstripping step by step. Before you begin, collect your tools and supplies. Here are the items you need:

  • small pry bar
  • utility knife
  • caulking removal tool
  • tape measure
  • hammer and nails, screw gun and screws, or pneumatic fasteners
  • cleaning solution and cloths or paper towels
  • weatherstripping
  • caulking gun
  • high-quality, outdoor-rated sealant

Once you have these items, here’s how to proceed:

  1. Remove old weatherstripping or sealant from the garage door jamb with a pry bar. A caulking removal tool will make light work of the old caulking.
  2. Using a cloth and some household cleaner, wipe away any dirt, grease, or caulking residue from the area where you will install the weatherstripping.
  3. Inspect the jamb for holes, split wood, or rot. Fill holes with a paste wood filler rated for outdoor use as required.
  4. Measure and cut pieces of weatherstripping using your utility knife.
  5. Install the top piece of weatherstrip first. Work with the garage door closed so you can fix the weatherstrip firmly to the door surface. Make sure the strip is tight against the door. If you can push the door away from the stripping, it is not close enough. Using nails or another fastener, keep them at around 40cm (16”) intervals when securing.
  6. If desired, apply a bead of adhesive sealant first, then set the weatherstrip into the sealant and use nails, screws, or staples to hold it in place. (Some types of weatherstripping already have adhesive strips attached. Just peel and stick.)
  7. Repeat this process for each side of the garage door. Install the side strip starting at the top to ensure a tight fit against the top piece of weatherstripping.
  8. If you did not use sealant as you applied the strip, apply a bead of sealant along the edge of the weatherstripping opposite the door. This will stop any air leakage between fasteners.

Here’s how to determine the amount of weatherstripping needed to seal a garage door: 

  • Measure one side of the garage door, floor to top of the door, multiply by two, and add the width of the door. This gives you the length of stripping needed for one door. 
  • If you have more than one door, multiply this length by the number of doors you have. This is your total.

How to seal garage door gaps: The best sealants 

Even with quality weatherstripping, you will still have some gaps where air, moisture, and tiny pests can sneak in, especially between fasteners. Here’s an easy way to fix that problem.

Use a high-quality sealant and seal between the weatherstripping and the doorframe. The best method is to seal the entire length of the weatherstripping, as this will not only seal any gaps but also add an additional barrier to prevent air from entering. Doing so will provide a more uniform and attractive appearance as well.

Do projects right the first time with LePage Quad Max Window, Door & Siding Sealant. Quad Max is an extremely durable and flexible sealant that will bond permanently to the door jamb and stand up to UV exposure as well as harsh weather conditions. The sealant is available in a wide range of colours, so you’ll likely find one to match your home. For a custom tint, Quad Max is also paintable about an hour after application.

Give your weatherstripping all the support it needs with a premium sealant designed for the great outdoors! Use LePage 2in1 Seal & Bond as you install the weatherstripping. Seal & Bond is designed to function as both a sealant and a permanently flexible adhesive. Apply a bead of Seal & Bond to the doorframe, then install the weatherstripping using nails or staples as described above. This will strengthen the bond and prevent air and moisture leaks as well. Seal & Bond is mildew and mould resistant, giving you a lasting seal!