Weatherstrip types by application, door sweeps, foam sealants, and priority sealing locations
Weatherstripping is a material installed around doors and windows to seal gaps and prevent air, moisture, and drafts from entering your home. Air sealing is the broader practice of identifying and sealing air leaks throughout your home's building envelope using caulk, foam, and other materials.
Together, these techniques can reduce heating and cooling costs by 15-30%, improve comfort, prevent moisture problems, and reduce dust and pest infiltration. The Department of Energy estimates that air sealing is one of the most cost-effective home improvements available.
| Type | Best Use | Durability | Cost | Notes |
|---|---|---|---|---|
| V-Strip (Tension Seal) | Door jambs, window channels, double-hung windows | Excellent (10+ years) | $ | Durable metal or vinyl. Nearly invisible when installed. Provides excellent seal. |
| Foam Tape (Open/Closed Cell) | Window sashes, door stops, garage doors | Fair (2-4 years) | $ | Easy DIY installation. Self-adhesive. Compresses to seal gaps. Not for high-traffic areas. |
| Door Sweeps | Bottom of exterior doors | Good (5-8 years) | $-$$ | Screw or adhesive mount. Brush, vinyl, or rubber blade. Measure door width carefully. |
| Bulb Gaskets (Tubular) | Door jambs, thresholds, garage doors | Excellent (8-10 years) | $$ | Hollow rubber/vinyl tube. Excellent compression seal. Metal or vinyl reinforced. |
| Felt Weatherstripping | Low-traffic areas, attic hatches | Poor (1-2 years) | $ | Inexpensive but not durable. Absorbs moisture. Use only for rarely-opened areas. |
| Magnetic Weatherstripping | Metal doors, refrigerator-style seals | Excellent (10+ years) | $$$ | Superior seal. Self-closing. Commonly used on high-performance doors. |
| Silicone Bulb Seal | High-temperature areas, metal doors | Excellent (10+ years) | $$ | Extreme temperature resistance. UV stable. More expensive but longest-lasting. |
| Kerf-In Weatherstripping | Door jambs with kerf grooves | Good (6-8 years) | $$ | Slides into existing saw kerf. Clean look. Requires kerf groove in door jamb. |
| Product Type | Best Applications | Gap Size | Paintable? | Key Considerations |
|---|---|---|---|---|
| Acrylic Latex Caulk | Window/door trim, baseboards, interior gaps | Up to 1/4" | Yes | Easy cleanup, paintable, good for visible areas. Not for high-movement joints. |
| Silicone Caulk | Bathrooms, kitchens, exterior windows | Up to 1/2" | No (usually) | 100% waterproof, flexible, durable. Not paintable. Use for moisture-prone areas. |
| Siliconized Acrylic Caulk | Exterior trim, siding, painted surfaces | Up to 3/8" | Yes | Hybrid formula. Paintable, flexible, weather-resistant. Best all-purpose option. |
| Low-Expansion Foam | Windows, doors, large gaps, rim joists | 1/4" to 3" | Yes (after trimming) | Expands 15-30%. Won't warp frames. Use "window and door" foam around openings. |
| Standard Expanding Foam | Large holes, rim joists, attic penetrations | 1" to 4" | Yes (after trimming) | Expands 100-300%. Can distort framing if overfilled. Not for windows/doors. |
| Fire-Blocking Foam | Top/bottom wall plates, pipe penetrations | 1/2" to 2" | Yes (orange color) | Code-required for certain penetrations. Intumescent (expands in fire). Check local codes. |
| Backer Rod + Caulk | Large gaps, control joints, foundations | 1/2" to 2" | Depends on caulk | Foam rod fills gap, caulk seals surface. Best for deep gaps. Creates proper caulk shape. |
| Spray Foam (DIY Kit) | Rim joists, attics, crawl spaces, large areas | 1" to 3" per pass | No (cover/trim) | Closed-cell insulates + seals. Requires PPE. Must cover per fire code. Consider pro install. |
Close door and check for light leaks and drafts. Remove old, damaged weatherstripping completely. Clean surfaces with rubbing alcohol to ensure good adhesion.
Measure each side of door jamb separately (height and width). Cut weatherstripping to exact measurements. For V-strip, add 1-2" extra for adjustments. Miter corners at 45° for clean appearance.
Start with the top (header). Position weatherstripping so it will compress when door closes. For V-strip, fold should point toward outside. For tubular gaskets, bulb should compress 25-30%. Fasten with nails or screws per manufacturer instructions.
Install hinge side first, then latch side. Ensure corners meet cleanly with header piece. Close door periodically to test compression and alignment. Adjust as needed before permanently fastening.
Measure door width and cut sweep to fit. Position sweep so blade just touches threshold (1/8" gap max). Mark screw holes, pre-drill, and fasten securely. Test door operation—should close easily without dragging.
Close and lock door. Check for light gaps around entire perimeter. Feel for drafts. Weatherstripping should compress evenly all around. Adjust positioning if gaps exist. Trim excess material with utility knife.
Open and close door several times to ensure smooth operation. Latch should engage easily without forcing. If door binds or is difficult to close, weatherstripping may be over-compressed—adjust thickness or positioning.
Note: Building codes and climate zone requirements vary by location. Some jurisdictions require blower door testing after extensive air sealing. Always verify local code requirements, especially for fire blocking and ventilation.
Disclaimer: This guide provides general information about weatherstripping and air sealing. Climate zones, building codes, and home construction methods vary significantly. In very tight homes, mechanical ventilation may be required for health and safety. Always consult with an energy auditor or building professional for comprehensive air sealing strategies, and verify compliance with local codes before beginning work.