How to Waterproof a Horizontal Crack Around a Window
- 1). Choose a water-based acrylic or silicone caulk to waterproof the horizontal crack around your window. Since this type of caulk is flexible, the waterproof seal will be maintained.
- 2). Wipe the surface around the horizontal crack with a wet cloth to remove any dirt. Let the surface dry.
- 3). Scrape away any existing caulk or other materials with a utility knife. Clean the area again with a cloth and mineral spirits. Let it dry.
- 4). Use scissors to snip off the end of the caulk cartridge. Load the cartridge into your caulking gun.
- 5). Place the nozzle of the caulking gun at the base of the horizontal crack at a 45-degree angle. Squeeze the trigger of the gun to release the caulk and move along the crack until it's completely filled. For a large crack, you could need two lines of caulk.
- 6). Run a popsicle stick along the edge of the caulk line to smooth it out.
- 7). Check the caulk seal in the horizontal crack once the caulk is dry. You should not see any spaces. If the caulk has settled and you can see small holes, add another layer of caulk for a completely waterproof seal.
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