To fix a leaking window frame, first inspect for gaps, cracks, or rot. Apply weather-resistant caulk to seal gaps and replace damaged sections with matching materials. Reinforce loose joints with wood glue or screws. For persistent leaks, install new weatherstripping or a storm window. Regular maintenance prevents further damage.

The effectiveness of these steps stems from addressing both structural and密封 issues. Caulking fills microscopic gaps (often 1/16th of an inch or larger) that allow water intrusion, reducing energy loss by up to 30% according to the U.S. Department of Energy (DOE). Replacing rotting wood (common in frames older than 20 years) prevents structural decay, which can increase repair costs by 200% if ignored. Weatherstripping, when properly applied, blocks 25-50% of air leakage, improving HVAC efficiency. A 2021 study by the National Association of Home Builders found that DIY window frame repairs save homeowners 10-20% on annual energy bills compared to professional installation. Neglecting leaks can also lead to mold growth, which the EPA links to 24% of indoor air quality issues. Proactive repair extends window lifespan by 15-20 years, as per the DOE’s Building Technology Program. Combining material replacement with sealing ensures long-term durability and cost savings.