Here’s How to Install Storm Windows to Shield Your Home From Rough Weather

Forecast got you down? We got you covered

Elisa Greenberg
Written by Elisa Greenberg
Updated July 26, 2022
 father and son looking out the window on a rainy day
Photo: Westend61 / Getty Images
Difficulty

Simple

Saturday skill builder.

Time to complete

3 hours

Two to three hours per window

Cost

$100–$450

Doing the labor yourself goes a long way.

Need professional help with your project?
Get quotes from top-rated pros.

What you'll need:

TOOLS

  • Drill
  • Putty knife
  • Tape measure
  • Caulk gun

SUPPLIES

  • Screws
  • Butyl caulk
  • Storm window

If you live in an area that gets hit with frequent storms, you’re probably eager for a little peace of mind knowing that your home is safe. Learning how to install storm windows can help you protect your house when a squall (or worse) rolls through. This guide teaches you how to install the storm windows you need to protect your home from the elements.

Why Add Storm Windows?

Storm windows protect your home against severe weather, so they’re ideal for homeowners who live in regions that tend to get hurricanes, tornadoes, or blizzards. In addition to their durability, they are also efficient at keeping your home warm in the winter and cool in the summer. 

Here are all of the benefits of adding storm windows to your home:

  • Withstand winds up to 170 mph

  • Resist shattering when struck by flying objects

  • Improve home insulation

  • Save you an average of 10% to 30% in annual heating and cooling costs

  • Comes in a variety of materials, including vinyl, wood, and aluminum

  • Easy to remove and clean

  • Reduces outside noise

  • Eliminate condensation

  • Can be installed on your home’s interior or exterior

7 Steps to Install Storm Windows

  1. Many Any Necessary Repairs

    When installing a storm window, you want to give it a clean, smooth, and dry surface. Conduct a once-over on your window and see if there are any repairs that you need to make. Check for rotten wood and remove it. Also, scrape off paint and caulk the window. Doing this will not only ensure your storm window is energy efficient, it will help it hold up better to rain and wind.

  2. Measure Your Window Size

    woman measuring window width
    Photo: Gerald Carter / Creative Flame / Adobe Stock

    You’ll need to measure the height and width of your window to get a proper fit. To find the height of your storm window, measure the left side of the window’s height inside the frame, following the window’s jamb or side. Repeat this process in the center of the window and to its right. Use the shortest dimension for the window’s height. 

    To measure your window’s width, start from its bottom, above the sill, then move inside its frame, measuring from jamb to jamb. Repeat these steps in the center and top of the window. Use the shortest dimension for the window’s width.

  3. Check for Proper Fit

    After taking your window’s measurements, determine if you have a Western casing which means it’ll have approximately a five-eighth of an inch blind stop inside the window opening. And require one-fourth of an inch shorter and narrower than the casing opening. If you have an Eastern casing, your storm window will overlap and attach to the casing and will need to be five-eighth of an inch taller than the casing.

    Place your new storm window inside the opening to check for a proper fit. You can determine which side is the top portion and which is the bottom by looking at the movable panels' direction. To ensure the right fit, look for any gaps. Also, confirm that all your storm door’s screw holes land on solid wood. Once you’ve conducted your examination, remove the window. 

  4. Caulk the Top and Sides

    Use your butyl caulk and generously caulk your windows on the top and sides of the back of your window. Do not caulk the bottom. Using a pulling motion, hold the caulking gun at a constant angle and slide the nozzle along the joint while pressing the trigger with equal pressure.

  5. Place the Window Into the Opening

    man installing storm window panel
    Photo: Mint Images / Adobe Stock

    Place your storm window back into the opening based on the manufacturer’s instructions, top first ensuring a tight fit, and temporarily securing the top corners with screws. Use your putty knife to press gently against the glass edges for an airtight seal. Then secure it into its frame with a drill and the provided screws.

  6. Adjust the Expander on the Bottom of the Window

    Adjust the expander on the bottom of the storm window and press down on it with your putty knife for a tight fit. Typically, storm windows come with a windowsill expander, which allows the window to expand up to about 1/2-inch to ensure the snuggest fit. The expander should make even contact across the bottom sill. 

    Then square up the window unit and install the remaining installation screws. Make sure the gap between the window and the frame is even.

  7. Check for Weep Holes

    Ensure your storm window has at least two weep holes to allow it to drain any moisture that’ll potentially accumulate behind it. If it doesn’t, use your drill to create two or three at the bottom edge of the expander.

Installing Storm Windows Yourself vs. Hire a Pro

If you’re installing an exterior storm window, you’ll need to accurately measure your window and ensure it’s properly sealed and secured. If you’re not confident that you can seal and secure it correctly, this project is best left to the pros. It’s also safer to let a professional work their magic if you have multiple stories that’ll require you to use a ladder. If you do choose to install storm windows on a second story or higher, remember to always practice good ladder safety precautions. 

The cost to install a storm window is $90 to $400 per window plus a $30 to $65 per hour labor fee if you hire a pro. With a professional window installer, most offer warranties on their work up to 10 years.

FAQs

Is it easy to install storm windows?

Installing storm windows is a relatively straightforward project for DIY-savvy homeowners. They take an average of two to three hours per window to install.

tHowever, if you’re looking to install storm windows for several windows or windows on upper floors, the project becomes more complex. In that scenario, it’s best to hire a local window company to handle the job. 

Can you install storm windows from inside?

You can install storm windows inside of your home. In fact, interior storm windows offer excellent insulation and have the benefit of not being exposed to the outdoor elements. For this reason, they typically last longer than outdoor storm windows.

Do storm windows need to be tempered?

Yes—according to the International Association of Certified Home Inspectors, tempered glass is stronger and can withstand temperatures higher than laminated glass.

Tempered glass is important for storm windows because it protects against outside elements and household accidents by not producing sharp, jagged pieces when they break or shatter.

Need professional help with your project?
Get quotes from top-rated pros.