Stopping drafty windows in winter usually takes both caulk and weatherstripping. As a family-run, woman-owned exterior remodeling company, Coastal Windows & Exteriors serves 730+ towns across Massachusetts, New Hampshire and Maine with 7,000+ installations completed since 2011. Most homes benefit from both to seal out cold air.
How the Two Seals Differ
- Different jobs: Caulk seals fixed gaps, while weatherstripping seals parts that open and close. If drafts persist, get a free estimate this fall.
- Caulk spots: Use caulk where trim meets siding and around fixed frames.
- Moving parts: Door weather stripping and window sash seals cover the parts that move every day.
- Hidden gaps: 89% of U.S. homes are under-insulated, per the Insulation Institute. Air sealing is a smart fall step.
- Replace instead: ENERGY STAR certified windows and doors can cut heating and cooling bills by up to 13%. Worn units often need replacing.
| Method | What It Seals | Where It Goes | Best For |
|---|---|---|---|
| Caulk | Fixed, non-moving gaps | Trim-to-siding joints, fixed frames | Sealing stationary cracks |
| Weatherstripping | Moving parts | Door edges, window sashes, thresholds | Doors and windows that open |
Sealing Your Home This Fall
Top Recommendation: Use both caulk and weatherstripping to seal drafty windows in winter. Book a free estimate if drafts persist.
Better Fix: Replacing worn, failing units beats resealing them year after year.
Smart for Fall: Checking both seals now readies your home for heating season.
Request a free window estimate from Coastal Windows & Exteriors.
Browse our complete windows FAQ guide from Coastal Windows & Exteriors.
Explore the Coastal Windows & Exteriors Windows Exterior Remodeling Home Improvement Help Center.
Still have questions about What Is the Difference Between Caulking and Weatherstripping, and Do I Need Both? See the areas we serve and talk to your local window and door contractor.
Last Updated: September 2026
Sources:
- 89% of U.S. homes are under-insulated. Insulation Institute ICF Report: 89% of Homes Are Under-Insulated, industry report on residential insulation gaps. (2024)
- ENERGY STAR certified windows and doors can cut heating and cooling bills by up to 13%. ENERGY STAR Windows, Doors & Skylights, official guidance on certified product energy savings. (Accessed September 2026)
