How to DIY Window Sealing: Simple Tips to Save Time and Money

Knowing how to properly seal your windows can save you both time and money. A good seal creates a watertight barrier that keeps out unwanted moisture and insects, while helping maintain a comfortable indoor temperature year-round. With a few easy tips, you'll be sealing windows like a pro.

1. Check for Air Leaks

Start by inspecting your window frames for any air leaks. A simple trick is to light a candle or match and hold it near the frame. If the flame flickers or goes out, that’s a sign of a draft and an indication that there may be an air leak.

2. Choose the Right Caulk

Selecting the right type of caulk is key for long-lasting results. For windows, look for a product suitable for both indoor and outdoor use. Our TNS-771 Neutral Silicone Sealant and TAS-694 Acetic Silicone Sealant are perfect choices for both interior and exterior window installations. If your windows are made of aluminum, we also offer a high-performance Polyurethane Sealant designed for aluminum frames.

3. Prepare the Window

Before applying the new caulk, make sure the surface is clean and dry. Remove any old caulk from the window frame and wipe the area down with a damp microfiber cloth or a sugar soap wipe to remove dust and debris. This ensures that the new caulk will adhere properly.

4. Use Masking Tape

Apply masking tape along the edges of the window frame, leaving a 5mm gap between the tape and the frame. This will help create a straight, clean line when you apply the caulk, giving your window seal a professional finish.

5. Load the Caulk Gun

Insert the caulk tube into the caulk gun and cut the tip of the nozzle at a 45-degree angle to match the width of the gap. Test the caulk gun on a scrap piece of paper or wood to ensure a smooth, even application.

6. Apply the Caulk

Start on the outside of the window, applying a continuous bead of caulk along the seam where the window frame meets the wall. Use a finishing tool to smooth the caulk, ensuring a tight seal. If you don’t have a finishing tool, you can use your finger—just dip it in warm, soapy water and gently smooth out the caulk. Once you’re done, remove the masking tape and wipe away any excess caulk with a damp cloth.

7. Inspect the Seal

After the caulk has dried, check the exterior window frame for any gaps. Touch up as needed to ensure the seal is completely airtight. Once you’re satisfied with the exterior, move indoors and repeat the process on the interior window frame.