To measure your gap accurately: 1) Close the door or window completely. 2) Use a feeler gauge or a stack of coins/papers to determine the widest point of the gap. 3) Measure in at least 3 locations (top, middle, bottom for doors; all four sides for windows). 4) Use the largest measurement as your working gap size — weather stripping needs to seal the widest point. 5) For irregular gaps, consider adjustable or compression-type seals. A common mistake is measuring only one spot and ending up with an under-sized seal.

For exterior doors, tubular rubber or reinforced silicone are typically the best choices. They offer excellent compression recovery, handle wide temperature swings, and resist water infiltration. For the bottom of the door, a door sweep with a rubber fin provides superior protection against drafts and moisture. If the gap is under 1/8", closed-cell foam tape with an adhesive backing is a budget-friendly option that still performs well.

While some materials work for both, windows and doors have different requirements. Windows typically have smaller, more uniform gaps and benefit from low-profile options like V-strip (tension seal) or thin closed-cell foam tape. Doors experience more movement, heavier use, and often larger gaps, making tubular rubber, door sweeps, or reinforced seals more appropriate. Using a door-specific seal on a window may prevent proper closing, while using a window seal on a door may wear out quickly.

The lifespan varies significantly by material: Felt: 1–2 years (absorbs moisture, wears quickly). Foam tape: 2–5 years (compression set reduces effectiveness). V-strip: 5–10 years (good durability for doors/windows). Tubular rubber & silicone: 8–15+ years (excellent longevity, especially silicone). Interlocking metal: 20+ years (but requires professional installation). Regular inspection and cleaning can extend the life of any weather stripping.

If your gap exceeds 3/4 inch, consider these options: 1) Use a bulb seal or heavy-duty door sweep designed for large gaps (some handle up to 1"). 2) Install a door shoe with multiple fins for extra coverage. 3) Combine a backer rod (foam filler) with sealant to reduce the effective gap size, then apply weather stripping. 4) For gaps over 1 inch, the door or window may be misaligned — consider re-hanging or adjusting before sealing. 5) In extreme cases, a threshold riser or door bottom extender can bridge large bottom gaps.

Adhesive-backed (peel-and-stick) weather stripping is easier to install, requires no tools, and works well for renters or quick fixes. However, it may fail in high-moisture areas or under heavy use. Nail-on, screw-on, or kerf-fit weather stripping is more secure, lasts longer, and is preferred for exterior doors and high-traffic areas. For the best of both worlds, choose a product with a strong acrylic adhesive (not cheap foam tape) or opt for a compression-fit design that stays in place without fasteners.

Garage doors require specialized weather stripping due to their size and exposure: Bottom seal: Use a bulb seal or T-style rubber gasket that slides into the bottom retainer channel — measure the channel width before purchasing. Sides and top: Vinyl or rubber trim with a flexible fin nailed to the exterior frame works best. Between panels: Some sectional doors have built-in seals; if worn, replace with OEM-style gaskets. Always choose UV-resistant and cold-weather flexible materials for garage applications.

Open-cell foam is softer, more compressible, and better for irregular gaps — but it absorbs water and breaks down faster outdoors. It's best for interior applications like interior doors or soundproofing. Closed-cell foam is denser, water-resistant, and more durable — making it suitable for exterior doors and windows. It has better insulating properties (higher R-value) and resists moisture, mold, and mildew. For any application exposed to the elements, always choose closed-cell foam.