Avoid chilly drafts with these handy window-insulating techniques
If your idea of a perfect winter day is sipping cocoa in front of your favorite picture window while watching the snow flutter to the ground; only one thing can ruin it—drafty windows.
If there’s an icy breeze constantly seeping through your windows, it’s time for action. Learn how to seal windows for winter to avoid air leaks and cold drafts.
Before Insulating Windows
You shouldn’t start taking the actual steps to insulate a window unless you do some prep work first.
Start by cleaning the entire area around the window, including the casing around the glass, the jambs, and the horizontal sills.
Use a dry microfiber cloth to remove dust and other grime. If you see some sticky substances or grime that doesn’t wipe away easily, moisten the microfiber cloth or apply a gentle household cleaner. The cleaning process should only take a few minutes. Then, allow your windows to dry for another few minutes.
As you’re wiping down the window casing, look for water discoloration that could indicate a water leak. If you notice a dark substance that looks like mold along with water discoloration, stop wiping the area and call a local window repair pro to inspect the window.
Now, it’s time to look for air leaks around the window. On a windy or cold day, hold your hand near various areas of the window frame. If you feel a draft or moving air, inspect the window frame inside and outside. If you notice cracks or loose building materials, this is the likely source of the leak.
If you are unsure whether you are feeling drafts, you can light a candle and hold it near the area where you believe the leak may be occurring. If the flame moves when near the window, it likely indicates a leak. (Be sure to turn off all nearby ceiling fans first.)
Inspect the caulk between the glass and window frames on the window’s exterior and interior. If the caulk is curling, pulling away from the window, or missing, you should plan to add more caulk to insulate the window.
Typically, the caulk on the interior portion of the window doesn’t need replacing as often
as the exterior caulk because it doesn’t have weather exposure. However, in some cases, it may need replacing around the panes, along the sill, or the trim.
If you need to replace the glass in any window, add insulation film, or replace a window entirely, you’ll need to accurately measure the size of the rough opening for the window.
Measure the distance from the inside edge of the side jambs horizontally and from the inside of the head jamb and the sill vertically. Take three total measurements in each direction (top, middle, and bottom or right, middle, and left). The smallest measurement in each direction equates to the rough opening for the window.
How to Seal Windows for Winter
You have a few different options in order to insulate a window ahead of any chilly weather.
Remove and Apply New Caulk to Windows
Remove any damaged caulk, and then wipe away any dust or grime from the area where you will apply the caulk.
Apply new caulk explicitly made for exterior surfaces between the frame and the home’s siding. Use clear caulk or select a color to match the woodwork for interior windows.
Pro tip: Remember to avoid adding caulk to the seams where the window frame opens, or you’ll caulk the window shut.
Add Weather Stripping to Block Any Gaps
Weather stripping works like caulk, blocking gaps between the glass pane and the frame where chilly air could seep indoors. Weather stripping is a less permanent solution than caulk, and it doesn’t blend in as easily with your window. However, weather stripping is affordable and easy to install, so it’s a viable option for insulating a window.
Inspect your weather stripping for signs of damage or loose areas. If the weather stripping around your windows needs replacing, you’ll first have to remove the old weather stripping completely.
Pressure-sensitive foam weather stripping is the easiest to apply, and you can add it to areas of the window that do not create friction. The foam could pull away as the window slides across it.
Or, if you do not plan to open your windows for a few months during winter, you can use the foam anywhere. It can go in areas like the lower sash, the upper sash, and along the sides of the frame. To install it, try the following steps:
Use water and mild dish soap to clean the sash where the weather stripping will go.
Wipe the area dry with a clean cloth and then allow any remaining water to evaporate over several minutes.
Cut the weather stripping to match the length of the area where you will attach it.
Remove the protective backing and press the adhesive layer on the foam in place.
Repair Any Broken Glass
Broken glass in your windows will affect the ability to keep cold drafts out of your home. The cost for window repair typically averages from $40 to $100 for fixing a cracked pane and from $200 to $500 for replacing window glass. Replacing cracked glass also provides an aesthetic benefit, making it worth the investment during any season.
We strongly recommend hiring a pro, but you can attempt to remove and repair broken glass in a window yourself with the following steps:
Prepare to remove the broken pane: Using painter’s tape or duct tape, create an X with tape in the middle of the pane to safely hold the glass together if it breaks further.
Remove the broken pane: Remove the caulk or putty holding the pane in place. Carefully wiggle the pane out of the frame.
Prepare the pane: If you purchased a new pane, it should be ready to install with no prep work. If you want to repair the cracked frame, apply epoxy to it.
Install the pane: Place the pane inside the blank space in the window. Use caulk or putty to secure the pane to the frame.
Add Window Insulation Film
Although some homeowners debate whether window insulation film is effective, it offers some benefits for older windows with single-pane glass. The plastic window film cuts down on cold air entering from the outside while keeping the warm air in your home from leaking outward through the glass. Keep in mind that some people dislike the aesthetic of using window insulation film, especially since you’ll be looking at it all winter.
To apply window insulation film:
Wipe the frame with a damp cloth to remove dust before allowing it to dry in the air.
Cut the film to the dimensions of the window frame, leaving a few extra inches on all four sides.
Apply the two-sided tape to the frame.
Remove the protective layer from the tape.
With the top side of the two-sided tape now exposed, stick the film to it, leaving a few inches of overhang.
Once you attach the film securely on all four sides, run a hair dryer back and forth a few inches from the film to shrink and tighten it to remove wrinkles.
Continue warming the film until all wrinkles disappear.
How to Seal Windows in a Pinch
Insulating windows doesn’t have to involve anything fancy—these hacks can do the trick and keep your home more comfortable.
Use Bubble Wrap
If you receive packages protected with bubble wrap—and if you can wrestle it away from the kids before they pop all of the bubbles—you can use the bubble wrap for a quick and easy solution to stop window drafts.
Granted, it won’t look aesthetically pleasing, and you won’t be able to see out of the window. That’s why many homeowners use this solution if they’re in a pinch or waiting to install a more permanent solution. However, securing bubble wrap with masking tape over the interior face of a window works surprisingly well to insulate windows and prevent heat loss.
Create a DIY Draft Stopper
For the quickest and least-permanent solution to drafty windows, place a draft stopper along the window sill where cold drafts may be entering. While this idea isn’t a long-term fix, you can create a DIY draft stopper using household goods. However, the stopper doesn’t work if the air leak originates around the window glass or anywhere along the frame other than the sill.
To save money by making your own draft stopper, rather than purchasing one, follow these steps.
Cut a piece of fabric a few inches longer than the length of the window sill and wide enough to become a tube.
Sew the fabric to connect the two long edges.
Sew one end of the fabric to create a closed end.
Fill a little bit of the tube with unpopped popcorn, gravel, or some marbles to provide some weight.
Stuff the remainder of the tube with socks, old t-shirts, old towels, or other fabrics.
Sew the end of the tube shut, so nothing leaks out of it.
Place it along the sill to try to block any leaking air.
Long-Term Window Insulation Solutions
If you want a solution that will keep your windows insulated for years to come, opt for one of these solutions.
1. Install Storm Windows
Although few people use storm windows in modern homes, they are still an option for winterizing windows. If your house has single-pane glass windows, they may be able to work with a storm window, which is an extra piece of framed glass that snaps into place on the interior or exterior of the current window.
Adding storm windows is an expensive fix, with an average cost of $8,200, plus you have to match the type of storm window to your window for a perfect fit.
2. Add Window Treatments
When aiming to insulate a window, you can also use interior design to your advantage. For instance, you can add window treatments like thermal curtains, which are thick, cozy, and help to keep cold air from getting into your home. You can also opt for energy-efficient window treatments like cellular shades to keep your home comfy all year long.
When choosing new window treatments, do your research before making a purchase so you can get the look you want while also increasing your window’s insulation.
3. Insulate Around Your Windows
If you believe the air leaks are occurring because of poorly fitting windows, you can remove the jambs around the frame and add insulation.
After carefully removing the jamb, place insulation in any areas where you see open spaces. Options for insulation materials include:
Fiberglass: You can cut fiberglass batting insulation to fit the gap, and it should block air drafts. Do not ball up the fiberglass, as this reduces its effectiveness.
Spray foam: You may be able to add expanding spray foam into the gap around the window. Add this foam slowly and carefully, as too much foam could push a loose window out of alignment as it expands.
Frequently Asked Questions
Using plastic shrink film over the window will cut down on drafts, which makes the air inside your home feel warmer. Plastic shrink film doesn’t quite have the insulative properties of a new window or of adding insulation inside the window jamb, but it will help. Plus, it’s a cost-effective solution to keeping your home warmer (more on that in a second).
If you have bubble wrap lying around the house from packages you received, and if you don’t care about the odd look, tape bubble wrap over the window. This solution has almost no cost to you if you already have bubble wrap on hand.
Another inexpensive option for insulating windows is to add new caulk around the glass. This step quickly cuts down on air drafts for older windows, and a tube of caulk only costs a few dollars.
Adding plastic shrink film around the glass is another cost-effective option. Purchase a kit of plastic film for a few dollars per window.
Use a high-quality type of caulk with silicone around your windows, as it is waterproof and shrink-proof. Or use a caulk consisting of polyurethane if you want to be able to paint over it. Caulk made from silicone is not paintable.
Avoid using inexpensive caulk that has a resin base or an oil base. These caulks will not last long and may shrink and pull away from the window as temperatures go up and down.