A drafty window can really interfere with your comfort on a chilly day. That small air leak also slowly drives up your heating and cooling costs throughout the year. Follow the steps for how to seal windows with silicone to solve both problems.

How to Seal Windows with Silicone Steps

1. Confirm that you have air leaks around the window.
2. Light a candle and pass it slowly along the edges of the window frame.
   1. Flickers show where drafts of air are leaking through from the outside.
3. Although air leaks may not be everywhere, you will seal the whole edge to create a uniform result.
4. Cut strips of masking tape and apply them along both sides of the seams between the window and wall.
5. Leave a small gap between tape strips where the silicone caulk will cover the seam.
6. Load a tube of silicone caulk into the caulking gun.
7. Squeeze the gun’s trigger to start pushing out sealant.
8. If desired, practice putting sealant on a piece of scrap wood to get the feel for how the caulk flows.
9. Position the tip at the top of a window seam and run a bead of silicone along the whole seam.
   1. Squeeze the trigger with gentle consistent pressure as needed to produce a uniform bead.
10. After laying a bead, swish a finger into soapy water and use it to smooth the silicone caulk over the seam.
    1. Only move your finger in one direction.
    2. Multiple finger strokes may be needed but try to smooth an entire seam with one steady swipe.
11. Repeat sealing and smoothing process on all sides.
12. Smooth together silicone beads at the corner joints with your finger.
13. Allow silicone caulk to dry according to manufacturer’s guidance.
14. Peel off masking tape.
15. Trim any stray blobs or strings of dried silicone caulk with the utility knife.