Having drafty windows that let in cold air can make your home feel chilly and increase your heating bills. Fixing drafty windows is an easy and affordable way to increase the comfort and energy efficiency of your home. Here are the steps for identifying and resolving any leaks or gaps that allow air to flow through your windows.

Inspect Windows for Air Leaks

The first step is to thoroughly inspect each window in your home to locate any spots where air is getting through. Here’s what to look for:

Check Around Entire Window Frame

Carefully run your fingers along each side of the window frame and sash and feel for any air movement. Air leaks often occur where the window sashes meet the frame or where the frame meets the wall. Leaks here allow air to bypass the window seals.

Check Window Sash Locks

Make sure the locks that hold the upper and lower window sashes together are properly lined up and sealing. Gaps around misaligned locks can let air flow through.

Inspect Window Seals

Examine the seals/weatherstripping around the perimeter of the window sashes. Look for areas where the seals are missing, damaged, cracked or peeling away from the frame. Compromised seals allow air to infiltrate around the edges.

Look for Condensation or Frost Buildup

Notice if there is any moisture, frost or condensation accumulating along edges of the glass or frame. This may indicate air leaks in those spots.

Feel for Drafts

On windy days, carefully run your hand around edges of the window frame and glass to detect air movement. Use a lit incense stick or candle to visually see drafts around windows.

Listen for Wind Sounds

Quietly stand near your windows on windy days and listen closely for any whistling or whooshing sounds which may indicate air leaks.

Repair Air Leaks Around Window Frames

Once you’ve identified where air is coming in around your windows, you can seal up the leaks using caulk and weatherstripping.

Apply Caulk

Caulk offers an easy and inexpensive way to fill cracks and gaps around window frames. Remove any old cracked caulk, clean the area thoroughly and apply a continuous bead of high-quality painter’s caulk around the interior window frame and exterior where it meets the siding. Smooth down the caulk with a putty knife or finger. Allow time to dry before painting over it.

Install Foam Weatherstripping

Foam weatherstripping tape can seal leaks between movable window sashes and the frame. Clean the contact areas thoroughly, cut strips of tape and press firmly into place along sash channels. Choose thicker, dense weatherstripping for maximum energy efficiency.

Use Window Weatherstripping Kits

For an easy fix, purchase a pre-cut weatherstripping kit made specifically for windows. Kits contain compression-fit vinyl strips that press into the window channels for a tight seal. Measure window height and width before buying to get the right sized kit.

Stuff Foam Sealant into Gaps

For small gaps and cracks, spray foam sealant can prevent drafts. Insert the plastic nozzle into cracks and fill completely with foam. Allow it to fully cure and then trim off excess with a knife. Use minimally expanding foam so it doesn’t warp the window.

Add Window Draft Stoppers

Adhesive-backed foam window draft stoppers provide a quick solution for sealing air leaks around drafty windows. Simply cut strips to size, peel and press them into place between the window sashes or around the frames. Get thicker draft stoppers for wider gaps.

Increase Efficiency with Plastic Film Window Kits

Shrink-fit plastic window insulation kits provide an inexpensive, temporary seal against air leaks in winter. They are an easy do-it-yourself solution that can lower heating costs.

Purchase Window Shrink Film Kit

Get a window insulation kit that contains thick plastic sheeting with adhesive strips around the border. Measure your window size and get a kit that’s at least a few inches larger to ensure a tight fit.

Clean Window Frame

Thoroughly clean the entire window frame with rubbing alcohol to remove dirt and oils so the adhesive strips stick properly. Pull off any old caulk.

Cut Plastic Film to Size

Lay the plastic sheet over the window and carefully cut it approximately 2 inches larger than the frame using scissors or a utility knife. Round the corners to avoid wrinkles.

Secure Film Around Frame

Remove the backing from the adhesive tape strips. Stretch the plastic tight across the window and press the adhesive securely onto the frame all the way around.

Use Hair Dryer to Tighten

After installing the film, use a hair dryer to gently heat and tighten it. The heat causes the plastic to shrink up any remaining slack. Avoid overheating.

Maintain Proper Moisture Balance

To avoid condensation buildup between window and plastic film, open the top of the window slightly to allow airflow. Make sure window frames have proper exterior drainage. Remove film in spring.

Adjust or Replace Faulty Window Hardware

Issues with window hardware like broken sash locks, improper jamblers or misaligned vertical slide tracks can also cause air leaks.

Check Sash Locks Align Properly

If sash locks don’t line up correctly between the upper and lower windows, air can get through. Adjust the keeper screws so the lock pins fit snugly into place when closed.

Ensure Jamblers Make Contact

Jamblers are the metal friction slides between the sashes. If they don’t meet properly, air will infiltrate the window. Bend or adjust jamblers until they touch evenly when closed.

Fix Misaligned Vertical Slide Tracks

For vertical (double-hung) windows, misaligned side tracks can create gaps along the vertical meeting rails and jambs. Adjust track screws to realign slides.

Replace Broken Hardware

For broken window locks, jamblers and vertical slide parts that can’t be fixed, compatible replacement hardware can be purchased at home improvement stores. Most brands use universal parts. Watch instructional videos to learn how to properly install replacement window hardware.

Consider Replacing with New Windows

For windows with extensive air leaks due to worn out parts and seals, replacement vinyl or fiberglass new construction windows can be more cost effective long term than continual repairs. Hire an experienced window installer for proper sizing and installation.

Perform Additional Weatherization

Along with fixing drafty windows, other energy efficiency improvements can further optimize your home’s comfort and air tightness.

Add Insulation

Increasing attic insulation to recommended R-49 level reduces heat transfer through ceilings. Insulating exterior walls prevents airflow through any hidden cracks.

Seal Ductwork

Leaky heating and cooling ducts can contribute to drafts. Seal duct joints with mastic paste and insulate all accessible ductwork.

Caulk Around Exterior Openings

Plug exterior cracks and openings throughout your home with weather resistant caulk to minimize cold air penetration into living spaces. Pay special attention around outdoor faucets, vents, pipes, wires and recessed lights.

Install Door Sweeps and Seals

Adhesive door sweeps and perimeter seals will stop drafts coming through exterior doors. Quality sweeps fill gaps at bottom of doors. Perimeter seals adhere to door frames to block air infiltration around the edges.

Upgrade to High-Efficiency HVAC Equipment

Replacing outdated low-efficiency heating and cooling systems with new Energy Star rated units can dramatically reduce your energy costs and air leakage. Have a professional handle sizing, installation and duct sealing.

How to Fix Drafty Windows – Key Takeaways:

Thoroughly inspect windows for leaks around frames, sashes, seals and hardware.
Use caulk, weatherstripping, plastic film and draft stoppers to plug leaks.
Repair or replace broken window hardware like locks and jamblers.
Consider installing new replacement windows if repairs are ineffective.
Improve overall weatherization with insulation, duct sealing, caulk and door weatherstripping.

Eliminating air leaks around drafty windows helps increase comfort and reduce energy waste in your home. Following proper sealing techniques and repairing window hardware issues can go a long way toward fixing window drafts on your own. For very leaky or deteriorating windows, new window installation may be required. Contacting a qualified window professional is recommended for any large scale window replacement projects. With some diligent inspection and DIY sealing steps, you can successfully remedy window air leaks, increase weather tightness and make your home more enjoyable to live in all year round.

Common Causes of Drafty Windows

Drafty windows that allow cold outdoor air to infiltrate into a home are unfortunately very common, especially in older properties. Identifying the specific causes of air leaks in your windows is the first step toward fixing the problem. Here are some of the most common causes of drafty windows:

Worn Out Window Seals

The seals and weatherstripping around window frames are meant to form an airtight barrier. Over time, exposure to sun, rain, pollution and temperature fluctuations causes seals to deteriorate and crack. Any gaps or voids allow outside air to pass through into the house. Old dried out seals need to be replaced.

Age and Damage

The longer a window is in service, the more likely it is to develop air leaks. The window frame and sash materials expand and contract through endless heating and cooling cycles over years of use. This can gradually warp and distort window components so they no longer fit together snugly. Any resulting gaps and holes will cause drafts.

Poor Initial Installation

If windows were improperly installed and gaps were left between the frame and the rough opening, it allows cold outdoor air to flow through. Any defects in installation alignment or sealant application can cause lifelong air leakage issues.

Hardware Issues

Problems with window hardware such as broken or misaligned sash locks, worn out jamblers and vertical slide tracks that don’t align correctly will create openings for air to get through the window.

Building Settlement

As a home ages, settling of the foundation and structural shifts can cause windows and window frames to move out of position and develop gaps where air can penetrate.

High Winds

Strong winds exert an enormous amount of pressure on building components. Any small cracks or weaknesses around windows will be exaggerated under high wind loads, allowing more cold air to push through.

By understanding what is causing your drafty windows, you can take appropriate steps to address the specific problems you are facing. Careful inspection, targeted repairs and upgrades to weatherization and window hardware will help eliminate sources of air leaks.

Signs You Have Drafty Windows

Detecting air leaks in the winter is much easier when there are obvious signs of drafts around your windows. Here are some of the most common indicators that your windows may need new seals, improved weatherization or repairs:

You Feel Cold Near Windows

If you notice that you feel chilled when standing or sitting beside certain windows even when the rest of the room feels comfortable, it generally means air is infiltrating around that window. The best way to confirm is to hold your hand near the glass and frame and feel for cold drafts.

Condensation and Ice Buildup

When warm indoor air comes into contact with cold window glass, it can cause moisture to condense and freeze, creating frost or ice around the edges. This indicates cold outdoor air is penetrating the window seals. Persistent condensation can lead to mold growth.

Window Coverings Move

On windy days, observe your curtains or blinds near windows. If you see them swaying or fluttering when the rest of the room is still, it means air is passing through gaps in the window frame.

Candles Flicker

One of the easiest ways to detect drafts is to light a candle near your windows on a windy day. If you see the candle flame leaning, wavering or flickering inconsistently then there is likely air movement where cold air is infiltrating past your windows.

You Hear Wind Noise

When it’s windy outside, listen closely to each of your windows. Any whistling, howling or whooshing sounds indicate gaps where air is penetrating the window seals or hardware.

High Heating Bills

If your home feels drafty and your heating costs are excessively high it can signal that cold outdoor air is gaining easy access indoors and forcing your heating system to work overtime to maintaincomfort. Sealing windows should be a top priority.

Identifying these signs of energy loss early on allows you to quickly diagnose and remedy air leaks through upgrades and repairs before the problem worsens. Tackling window drafts will make a huge difference in the temperature, comfort and efficiency of your home.

materials Needed to Fix Drafty Windows

With the right materials on hand, sealing up those drafty windows to prevent air infiltration is a straightforward DIY project. Here are the primary products you’ll need to thoroughly weatherize leaky windows and stop cold drafts from blowing in:

Caulk

A good quality caulk is essential for sealing gaps and cracks in window frames. Choose paintable silicone or latex caulking rated for at least 20 years. DAP Dynaflex 230 premium silicone is a top choice.

Weatherstripping Tape

Foam weatherstripping tape in various sizes is ideal for sealing leaks between movable window sashes and frames. Choose thicker, dense tape for maximum durability and compression.

Plastic Window Insulation Kit

Window shrink film kits provide a temporary insulating seal over entire windows. Purchase kits sized slightly larger than each window frame.

Spray Foam Sealant

Minimally expanding window and door spray foam fills narrow gaps around frames to block drafts. Look for low pressure formulations.

Window Draft Stopper

Adhesive foam blocks act as a barrier against air leaks around windows. Select window width-sized stoppers.

Replacement Window Hardware

For broken parts like locks and jamblers, new compatible universal replacement window hardware components can be purchased.

Wood Filler

Seal large holes and gaps around frames with acrylic latex window and door wood filler before caulking. It prevents air infiltration through deep openings.

Having these essential products on hand will allow you to tackle all the common types of window air leaks and drafts for a tightly sealed weather barrier. Follow manufacturer specifications for proper installation and application.

Step-by-Step Instructions

Follow these step-by-step instructions carefully to effectively seal air leaks and eliminate drafts around your drafty windows. Refer to the manufacturer’s guidelines for specific application directions based on the materials you are using:

Prepare the Window Surface

Clean all window frames thoroughly with soapy water to remove any dirt, grease and old caulk.
Use a putty knife to scrape off any loose paint or damaged caulk.
Sand paint edges to roughen the surface so the new caulk adheres properly.

Apply Caulk

Cut the tip of the caulk tube at a 45° angle to control flow.
Insert caulk cartridge into caulk gun.
Run a continuous smooth bead of caulk along the interior and exterior perimeter of the window frame.
Make sure the caulk fully seals around corners and fills any cracks.
Use a putty knife or finger to smooth out the caulk and shape into a concave fillet.
Follow drying time directions before painting over.

Install Weatherstripping

Carefully measure and cut weatherstripping tape to the required length for each window.
Thoroughly clean all contact surfaces with rubbing alcohol.
Peel off adhesive backing and stick tape along sash channels.
Firmly press weatherstripping into place to form an airtight seal.

Apply Expanding Foam Sealant

Insert the plastic nozzle deep into gaps and cracks around windows.
Slowly fill openings with foam sealant, allowing it to fully expand.
Once cured, trim excess foam flush with a sharp knife.

Install Plastic Film

Clean entire window frame with alcohol to improve adhesion.
Measure window dimensions and cut plastic film at least 2 inches larger.
Remove backing from adhesive tape border.
Stretch film tight over window frame and press tape firmly onto frame.

By methodically sealing all penetrations around window frames, you can successfully stop annoying and costly drafts from leaking air into your home. Visit the manufacturers’ websites for video tutorials on proper product application. Take a slow and careful approach to achieve optimal results sealing drafty windows.

Common Problems When Sealing Windows

Even when armed with the right sealing products and methods, you can still encounter issues getting drafty windows to properly seal up and prevent air infiltration. Being aware of these common problems ahead of time allows you to avoid them:

Inadequate Surface Prep

For caulk, spray foam and window film to adhere correctly, the window frame surface must be clean and free of dirt, grease and other contaminants. Failure to properly prep the surface can cause seals to fail prematurely.

Applying Caulk Incorrectly

Caulk needs to have a smooth, consistent bead with full contact to both sealing surfaces to work effectively. Gaps, voids or uneven caulk application can allow air to still penetrate. Avoid smearing or underfilling.

Choosing the Wrong Caulk

Not all caulk is created equal. Be sure to use high-quality caulk designed for windows and doors that remains flexible and rated for at least 20 years. Avoid cheap caulk that cracks and dries out quickly.

Forgetting Corner Seals

The caulk bead must be continuous around the entire window frame perimeter. Many DIYers forget to seal mitered corners which then leak air. Remember to completely caulk all four corners.

Sealing Only Half the Window

Caulking or weatherstripping only the interior window frame without addressing exterior leaks only solves half the problem. Make sure to seal both interior and exterior frame surfaces.

Improper Weatherstripping Installation

When sticking on weatherstripping tape, any gaps, wrinkles or imperfect adhesion prevent it from compressing to form an airtight seal. Take care to methodically press tape in place.

Overfilling Gaps with Expanding Foam

It’s easy to get carried away shooting expanding foam into cracks. Overfilling can warp window frames. Carefully insert only enough foam to fill gaps without