Window Seal Repair: Cost, Kits, DIY and More

Window seal repair is a project you only need to do once every few years. However, you can’t put off this vital home maintenance task.

Drafty windows leak out heated or conditioned air, making it impossible for your HVAC system to maintain your ideal indoor climate efficiently. If air can pass through your windows, water can too. Moisture doesn’t mix with many building materials, slowly compromising the structural integrity of wood window casings, uncoated metal hardware, interior paint, porous drywall and insulation.

Here’s a quick window seal repair guide for changing weather strips and applying caulk correctly while minimizing costs.

Window Seal Repair Cost — How Much and Who Should Pay

Window seal repair kits cost two to three digits, and those for defogging are more expensive because they include more advanced components. Ultimately, the number of units you need to fix determines how many kits you need for your project.

Moreover, hiring a window repair contractor will set you back a bit more, but you reduce the chances of improper seal installation or application.

Doing it yourself means you’re fully responsible for any mistake you may make. On the other hand, workmanship and callback warranties protect your pocket if the service isn’t up to snuff.

Repairing compromised window seals may not cost you a dime if the problem unit is under warranty or your homeowners insurance covers the damage.

If you follow your window manufacturer’s maintenance recommendations closely, the seal failure may result from defects in manufacturing, materials or workmanship — an issue your product warranty should cover.

Your homeowners insurance may pay for the repair if your window seals fail due to vandalism or a break-in. Review your policy to note how much your deductible is and know the claims process.

DIY Window Seal Repair or Hire a Pro?

DIY and professional window seal repairs have their merits. Only you can decide which direction makes more sense for your situation.

Window Seal Repair Tips for DIYers

Fixing broken window seals is less straightforward than you think. Here’s practical advice to pull off this project.

Buy the Right Product

Think twice before buying a window seal repair kit marketed as one-size-fits-all. Only some weather stripping adhesives and caulks suit exterior surfaces and can withstand the elements.

For weather strips, choose between rubber-based and silicone adhesives. For caulks, buy one optimized for outdoor use to stand up to water, ultraviolet radiation and constant temperature fluctuations.

Use Proper Equipment

The best tools for window seal repair are heat guns, hair dryers, putty knives, paint scrapers, adhesive removers, solvents and caulking guns.

Some can cause more harm than help, so buy the right window seal repair kit to avoid causing more problems than you solve. For example, a caulking gun with a thumb release conserves material more than its ratchet-style counterpart.

Put on personal protective equipment — such as safety gloves and glasses — to safeguard your skin and eyes.

This project can be messy, so cover the work area with a drop cloth to catch debris and simplify postrepair cleanup. Also, keep a bucket of water and a towel close when caulking to clean up mistakes quickly — especially when the sealant becomes runny because of the weather.

Remove Old Seals Correctly

Don’t scrape off old weather strips with abandon to avoid ruining window surfaces. Use a plastic scraper — not metal — to gently lift the adhesive without causing damage. If that fails, consider other methods.

With heat, hold the heat gun or hair dryer a few inches away from the weather strip. Move it back and forth until the adhesive is soft enough to remove.

With a commercial product — like a specialty adhesive remover, acetone or rubbing alcohol — test the solution on a small area first to see how the surface underneath reacts.

With baking soda, mix the compound with water to create a paste. Apply the mixture directly to the adhesive. Let it sit for a while before attempting to scrape it off.

Alternatively, use vinegar or coconut oil. Soak a cloth in either liquid and place it on the adhesive. The bond should loosen eventually.

Prepare the Surface

You need a sealant-free surface to ensure your weather strips or caulk adheres as strongly as possible. Any residual adhesive may leave gaps allowing air and water infiltration, defeating the purpose of sealing your windows.

Use a plastic scraper to remove all residual adhesive. Old adhesive can be stubborn, so take your time. Be patient to protect window surfaces.

Tips for Hiring a Reliable Window Seal Repair Contractor

Leaving window seal repair to a contractor makes sense if you have multiple problem units or have little time and energy to deal with the project. Plus, you may not be up to the task since working with upstairs windows involves significant risk.

However, professional service doesn’t guarantee excellent results. Here’s how to hire the right people for the job.

Clarify Whether a Window Contractor Does Repairs

Modern windows are deceivingly complex. Like roofers, window contractors are usually specialists — they either install or repair units but can seldom do both.

Those who exclusively install units deal with finished products, so they may not know how various components come together. Even those who live and breathe windows but are not set up to repair them may do a less stellar job.

Ask your prospective contractor explicitly if they repair windows to avoid wasting your time and money.

Verify Contractor Claims

All contractors would put their best foot forward to get business. Seek proof to verify claims instead of taking their word at face value.

Generally, window contractors need to obtain a license from the states they wish to operate in. This requirement subjects them to regulation, compelling them to play by the rules designed to protect consumers’ interests. 

Licensure usually requires contractors to carry adequate insurance policies and bonds. Therefore, a licensed contractor is almost always insured and bonded.

Ask for your prospective company’s license number. Use this information to search your state’s database of licensed professional contractors and fact-check their license’s validity. Also, request insurance and bonding proof.

More importantly, read reviews on Houzz, Angi, HomeAdvisor and Upwork. Testimonials let you know what their other customers have to say about them.

Ask About Warranties

Some contractor warranties are implied, which means they don’t have to appear on the contract to benefit from them since state law already requires them. Workmanship and habitability warranties are excellent examples.

Explicit warranties must appear on the contract. For instance, a callback warranty outlines the defects the contractor is liable for and what they do to address them.

Before committing, find out the coverage and length of your prospective window seal repair contractor’s warranties.

Hire Local

Local contractors are easier to hold accountable for mistakes because they have a reputation to protect in their communities. Home improvement scammers are usually out-of-town professionals who do slapdash work and leave unsuspecting customers high and dry when something goes wrong.

Ask about your prospective contractor’s office to determine if they genuinely operate locally. Trustworthy companies provide a local physical address, not just a P.O. box.

Ready to Tackle Window Seal Repair?

This home improvement has fewer moving parts than other projects. Still, you should approach it correctly to get your desired results, save money and keep your house intact.