Waterproof sealant: The right waterproof caulk to use

Don’t undermine your DIY repairs by using the wrong type of waterproof sealant. Find out which ones are the best and easiest to apply.

Waterproof sealant is an invaluable product used in both sealing the exterior of your home from the elements and protecting high water areas inside your home from damage. The best waterproof sealant is flexible, to allow for expansion and contraction over time, and is commonly used at junctions between dissimilar materials and exterior penetration, as well as to seal vertical and horizontal joints.

Waterproof caulk is most commonly used to seal exterior siding, trim, windows, doors and gutters. Waterproof caulk is flexible and paintable, and it will keep the exterior of your home looking great for decades. Silicone sealants that are waterproof are commonly used in bathrooms, specifically around showers and bathtubs, because it is washable and stops mould and mildew. 

1. Prepare the surface or joint for application by completely removing any old caulking or silicone using a utility knife, putty knife or special removal gel.
2. Clean the area thoroughly and allow to completely dry.
   
3. Cut the nozzle of the tube of sealant at a 45-degree angle as close to the tip as possible. (You can always make the hole bigger by trimming the tip further, depending on the size of the joint) 
   
4. Insert a piece of stripped copper wire into the hole created at the tip of the tube to pierce the seal at the junction between the tip and tube of the sealant (or, if your caulking gun has one, use the attached rod).
   
5. Insert the sealant tube into a quality caulking gun, preferably one with a dripless handle release.
   
6. Apply a continuous bead of sealant, evenly distributed by firmly pressing the sealant into the joint.
   
7. Smooth out the bead using a damp finger or specialty tool, depending on the width of the joint, to ensure even distribution and adhesion on both sides of the joint. (Pro tip: When installing silicone sealant, you can lightly spray the applied bead with glass cleaner before tooling to ensure the best results.)
   
8. Let the waterproof sealant completely dry for a minimum of two hours. (Check for the cure times printed on the tube)