Leaky windows can lead to a host of problems, including higher energy bills, water damage, and discomfort in your home. Whether the issue is due to aging seals, gaps around the frame, or minor cracks, addressing a window leak promptly is essential. Fortunately, learning how to seal a window leak is a straightforward process that can help protect your home and improve energy efficiency. This guide will show you how to tackle the problem step by step.

Steps to Seal a Window Leak

1. Identify the source of the leak
   1. Inspect the window both inside and outside to locate the source of the leak.
   2. Common areas include gaps around the frame, deteriorating caulk, or cracked glass.
   3. On a windy or rainy day, feel for drafts or look for water stains near the window.
2. Clean the area
   1. Thoroughly clean the window frame and surrounding surfaces.
   2. Use a damp rag with soapy water to remove dirt, debris, and old caulk.
   3. Allow the area to dry completely before proceeding.
3. Remove old caulk (if necessary)
   1. Use a putty knife or scraper to remove old, cracked, or peeling caulk.
   2. Removing old caulk ensures the new sealant adheres properly.
4. Apply new caulk
   1. Load the caulk gun with your chosen caulk (silicone for outdoors, acrylic latex for indoors).
   2. Apply a smooth bead of caulk along gaps in the window edges.
   3. Smooth the caulk with your finger or a caulk tool for a neat finish.
   4. Allow the caulk to cure as instructed on the packaging.
5. Install weatherstripping
   1. Measure the window dimensions and cut the weatherstripping to size.
   2. Peel off the adhesive backing and press the weatherstripping into place.
   3. Focus on areas where the window meets the frame to block drafts.
6. Seal larger gaps or cracks
   1. Use expanding foam sealant for gaps or cracks too wide for caulk.
   2. Apply sparingly, as the foam expands while curing.
   3. Trim excess foam with a utility knife once it hardens.
7. Apply shrink film (optional)
   1. Use clear plastic shrink film as a temporary fix or for added insulation.
   2. Attach the film to the window frame using double-sided tape.
   3. Use a hairdryer to shrink the film until it is taut.
8. Test the seal
   1. Run your hand along the edges of the window to check for drafts.
   2. Spray water to confirm that the seal prevents leaks.
   3. Make adjustments if needed.