8 Supplies for Weatherproofing Barn Windows Before Winter

When the autumn wind starts rattling the barn doors, it is a clear signal that winter is fast approaching. Leaving barn windows drafty and unsealed can quickly turn a cozy shelter into a freezing, damp hazard for animals. Armed with the right weatherproofing supplies, any hobby farmer can secure their outbuildings to keep livestock safe and feed costs manageable throughout the coldest months.

Disclosure: As an Amazon Associate, this site earns from qualifying purchases. Thank you!

Why Winterizing Barn Windows Matters for Livestock

Livestock are remarkably resilient, but drafts are their silent enemy. While animals can handle cold temperatures by growing thick winter coats, a constant, freezing draft blowing directly on them breaks down their natural insulation. This forces their bodies to burn extra calories just to stay warm, which quickly drives up feed costs for a small-scale operation.

Dampness is another major threat that accompanies drafty, unsealed windows. When cold air hits the warm, humid air inside a populated barn, condensation forms on walls and bedding. This excess moisture creates a breeding ground for respiratory illnesses like pneumonia, which can devastate a small herd of goats, sheep, or chickens.

Sealing up these drafts also protects the structural integrity of the barn itself. Water seeping through unsealed window sills freezes and expands, rotting the wood and loosening the glass over time. Taking the time to weatherize now prevents costly structural repairs when the spring thaw arrives.

Silicone Sealant – GE Silicone 2 Window and Door

External gaps around barn window frames are prime entry points for freezing rain and bitter winds. A high-quality silicone sealant acts as a flexible barrier, filling these voids and moving with the natural shifting of wood frames. Without it, water will seep behind the trim, rot the framing, and ruin any interior insulation.

GE Silicone 2 Window and Door is the ideal choice for barn environments because of its 100% silicone formula. Unlike acrylic caulk, it will not shrink, crack, or crumble when exposed to sub-zero temperatures or harsh UV rays. It also cures quickly, becoming rain-ready in just 30 minutes, which is crucial when working between autumn rain showers.

• Coverage: One 10.1-ounce tube covers approximately 50 linear feet with a 3/16-inch bead.
• Temperature limits: Apply in temperatures between 32°F and 120°F.
• Color options: Available in clear, white, and brown to match weathered barn wood.

This formula requires mineral spirits for cleanup, so keep a rag handy during application. It is also non-paintable, so apply it only where the final look does not need a coat of paint. This sealant is perfect for farmers dealing with older wood or metal window sashes that experience seasonal shifting, but it is not suitable for wet surfaces during application.

Caulking Gun – Dripless ETS2000 Ergo Composite

Squeezing thick sealant out of a tube with a cheap, rusty metal caulking gun is a recipe for hand cramps and messy, uneven beads. A reliable caulking gun ensures a steady flow of material, allowing for clean, professional seals around drafty window panes. It transforms a frustrating chore into a quick, satisfying task.

The Dripless ETS2000 Ergo Composite stands out because of its lightweight composite frame and 12:1 thrust ratio. This high thrust ratio means less hand squeeze pressure is required to push out thick silicone, which is a lifesaver when sealing multiple windows in cold weather. The dripless feature immediately stops the flow of sealant the moment the trigger is released, preventing wasted product on the barn floor.

• Frame material: Heavy-duty, lightweight engineered plastic composite.
• Extra features: Built-in spout cutter and clean-out poker tool.
• Compatibility: Fits standard 10-ounce caulk and sealant cartridges.

The composite body is incredibly durable but can feel different to those used to heavy steel guns. It requires occasional cleaning around the plunger to maintain the dripless function over years of use. This tool is a must-have for anyone with more than two or three windows to seal, especially older hands prone to fatigue, though it is not designed for massive, commercial-sized adhesive tubes.

Weatherstripping – Duck Brand Adhesive Foam Tape

Barn windows that need to open in the summer often leave massive gaps when closed for the winter. Weatherstripping fills these active joints, compressing tightly when the window is latched to stop drafts cold. It provides a temporary, removable seal that does not permanently lock the window shut.

Duck Brand Adhesive Foam Tape utilizes a high-density, closed-cell foam that resists moisture absorption and wind penetration. The self-adhesive backing clings tenaciously to wood, vinyl, and metal frames, even in dusty barn environments. Its high compressibility allows it to seal uneven gaps without preventing the window from latching securely.

• Dimensions: Available in 3/16-inch to 1/2-inch thicknesses to match various gap sizes.
• Material: Durable, weather-resistant PVC foam.
• Application temperature: Best applied when temperatures are above 40°F for maximum adhesive bond.

Dust and cobwebs will ruin the adhesive backing instantly. The window track must be thoroughly cleaned and dried before peeling the backing paper off the tape. This is the perfect solution for sliding or double-hung barn windows that must remain functional in warmer seasons, but it is not ideal for rough, unpainted wood surfaces where the adhesive cannot find a clean grip.

How to Assess Your Barn Windows for Drafts

Before buying supplies, walk through the barn on a windy autumn day to locate the worst offenders. Do not rely solely on visual inspection, as some of the most significant drafts come through invisible gaps. A simple, low-tech method is to hold a lit incense stick near the window edges; dancing smoke will instantly pinpoint air leaks.

Another effective technique is the physical touch test. Run a bare hand slowly around the perimeter of the window casing, paying close attention to the corners and where the sash meets the sill. If the wood feels damp or cold to the touch, or if there is a noticeable breeze, that area needs immediate attention.

Prioritize windows that face the prevailing winter winds, which usually blow from the north and west in most regions. Sealing these windward windows first will yield the most dramatic improvement in barn temperature. Keep a roll of painter’s tape handy during the assessment to mark leaky spots for quick reference when the tools come out.

Insulator Kit – 3M Indoor Window Insulator Kit

Most older barns feature single-pane glass windows that offer virtually zero insulation. An insulator kit creates a dead-air space between the cold glass and the barn interior, acting like a temporary double-pane window. This drastically reduces radiant heat loss and stops cold air from radiating off the glass onto nearby animal stalls.

The 3M Indoor Window Insulator Kit is renowned for its high-strength double-sided tape and crystal-clear shrink film. Unlike cheap alternatives that pull away from the frame at the first sign of cold weather, the 3M tape holds fast to clean wood or metal. Once applied, a standard hair dryer shrinks the film drum-tight, removing wrinkles and ensuring it won’t flap noisily in the wind.

• Coverage: Kits are available to cover up to five standard 3-foot by 5-foot windows.
• Material: Tough, puncture-resistant polyester film.
• Installation tool required: A hair dryer or heat gun on a low setting is needed to shrink the film.

Barn dust can interfere with the tape’s adhesive, so wiping down the window trim with rubbing alcohol prior to installation is a non-negotiable step. This kit is highly recommended for single-pane windows near kidding pens, brooders, or milking parlors where maintaining a stable temperature is critical. It is not suitable for windows that livestock can reach and chew, as the thin film can be easily punctured by curious animals.

Glazing Compound – Dap 33 Window Glazing

On old wood barn windows, the putty holding the glass panes in place dry-rots, cracks, and falls out over time. This leaves the glass loose, rattling, and prone to falling out during a winter storm. Applying fresh glazing compound seals the glass-to-wood joint, preventing water from rotting the sash and wind from whistling through.

Dap 33 Window Glazing is a classic, oil-based compound formulated for outstanding durability on wood and metal sashes. It remains slightly flexible long after application, allowing it to absorb the expansion and contraction of the barn wood without cracking. It applies smoothly with a putty knife, creating a clean, angled bevel that sheds water away from the glass.

• Container sizes: Available in convenient 1-quart and 1-gallon tubs.
• Skin time: Ready for paint in 7 to 14 days, depending on temperature and humidity.
• Application temperature: Apply when temperatures are consistently between 40°F and 90°F.

Oil-based glazing compound takes a week or more to skin over before it can be painted. Do not apply latex paint directly to wet glazing; use an oil-based primer first once it has skinned. This is the gold standard for restoring historic wood-framed barn windows, but it is not a quick-fix product if you need an instant seal that can be painted the same day.

Utility Knife – Stanley Classic 99 Retractable

Weatherproofing requires precise cuts on foam tape, plastic sheeting, and old, stubborn caulking. A dull or flimsy knife leads to jagged cuts, wasted materials, and potential safety hazards. A heavy-duty utility knife is the workhorse of this project, ensuring clean lines and quick work of tough materials.

The Stanley Classic 99 Retractable is an industry standard for a reason, featuring an indestructible interlocking nose that keeps the blade securely in place under heavy pressure. The die-cast zinc body stands up to being dropped on concrete barn floors or stepped on by livestock. Its three-position retractable blade allows for customized cutting depths, which is essential when scoring old glazing without scratching the glass.

• Body material: Heavy-duty die-cast zinc alloy.
• Blade storage: Holds up to 10 spare blades inside the handle.
• Inclusions: Comes with three standard utility blades.

Changing the blade requires loosening a flathead screw to open the handle. While this ensures the knife never accidentally pops open, it does require keeping a screwdriver nearby. This knife is perfect for any farmer who values durable, no-nonsense hand tools that last a lifetime, though it is not suitable for those looking for tool-free blade changes.

Plastic Sheeting – Frost King Polyethylene Roll

For windows that are beyond simple repair or sashes that are completely drafty, wrapping the entire exterior frame in heavy plastic is the ultimate defense. This creates a windproof barrier that takes the brunt of winter storms, protecting the fragile glass underneath. It is a fast, highly effective solution for large barns with numerous windows.

The Frost King Polyethylene Roll in a 4-mil thickness offers the perfect balance of durability and light transmission. This thick plastic will not tear under the strain of high winter winds, yet it still allows natural sunlight to filter into the barn, keeping the interior bright for the animals. Its UV-inhibited formula prevents the plastic from becoming yellow and brittle after a few months of sun exposure.

• Roll dimensions: Commonly available in 10-foot by 25-foot rolls, easily cut to size.
• Thickness: 4-mil (heavy-duty) or 6-mil (extra heavy-duty).
• Color: Clear, allowing maximum light penetration.

If not secured tightly, the plastic will flap in the wind, creating a loud noise that can spook sensitive livestock. Always use wooden furring strips over the edges to secure it flush against the barn wall. This sheeting is ideal for farmers looking for a quick, low-cost way to seal up unused windows or open-air vents for the winter, but it is not a permanent solution.

Staple Gun – Arrow T50 Heavy Duty Staple Gun

Trying to secure plastic sheeting with small nails or tacks in the freezing cold is a frustrating, finger-pinching task. A heavy-duty staple gun lets you secure materials with one hand while holding the plastic taut with the other. It is the fastest way to achieve a tight, professional seal on exterior window covers.

The Arrow T50 Heavy Duty Staple Gun is the undisputed benchmark for manual tackers, featuring an all-steel construction and hardened steel working parts. It delivers incredible driving power, sinking heavy staples deep into tough barn timbers without jamming. Its visual refill window lets you see at a glance when it is time to reload, saving you from dry-firing when high up on a ladder.

• Staple compatibility: Uses Arrow T50 staples in sizes from 1/4-inch to 9/16-inch.
• Body finish: Durable chrome finish that resists rust in damp barn environments.
• Mechanism: Patented jam-resistant design.

Operating this manual gun requires significant hand strength, especially when driving staples into aged, dense oak or pine barn framing. This tool is essential for any DIY farmer tackling seasonal weatherproofing, fencing repairs, or insulation installation. It is not ideal for those with limited hand strength, who might prefer a pneumatic or battery-powered alternative.

Step-by-Step Installation Tips for Farmers

Success in weatherproofing lies entirely in the preparation work. Start by clearing away dirt, cobwebs, and loose paint from the window frames using a stiff wire brush. If the surface is greasy or dusty, wipe it down with a mild detergent or rubbing alcohol and allow it to dry completely, as adhesives and sealants will not stick to dirty wood.

When applying the silicone sealant, cut the nozzle of the tube at a 45-degree angle to match the width of the gap you are filling. Hold the caulking gun at a consistent angle and pull it smoothly along the joint, applying steady pressure to the trigger. Use a gloved finger dipped in soapy water to smooth out the bead immediately after application for a clean, watertight finish.

For the plastic sheeting, cut the pieces at least two inches wider than the window frame on all sides. Secure the top edge first with a few staples, then pull the plastic taut toward the bottom and sides before stapling the rest. To prevent the staples from tearing through the plastic in high winds, sandwich the edges under thin wooden laths or furring strips before nailing or stapling them down.

Maintaining Ventilation While Blocking Cold Air

While sealing drafts is critical, a completely airtight barn is a dangerous environment for livestock. Animals constantly release moisture through their breath and waste, and ammonia fumes from urine can quickly build up to toxic levels. Proper winterization means blocking direct, freezing drafts at the animal level while allowing stale, moist air to escape near the roofline.

To achieve this balance, focus your weatherproofing efforts on windows located at or below the height of your animals. Leave high-up transom windows, ridge vents, or cupolas slightly cracked or unsealed to facilitate natural convection. Warm, moist air naturally rises and will escape through these upper openings, drawing fresh air in without creating a draft on the floor.

Monitor the barn’s humidity levels throughout the winter; if you notice condensation on the walls or a strong ammonia smell, you have sealed the space too tightly. Adjust the upper vents to increase airflow until the air smells fresh and the surfaces remain dry. Remember, a cold, dry barn is always healthier for livestock than a warm, damp one.

Taking the time to properly seal your barn windows before the first freeze ensures your livestock stay comfortable and healthy all winter long. With these eight essential supplies on hand, you can confidently tackle drafts and protect your outbuildings from the elements. A well-prepared barn brings peace of mind when the winter storms finally roll in.