As you’ll soon see, polyurethane, while being a heavy-duty adhesive, is also an organic substance that breaks down with constant UV exposure. Silicone, however, doesn’t, making generally a better option. In the post, read up on the details of these two types of adhesives and find out which one is best for your caulking project.
Polyurethane Caulk
Polyurethane is an organic compound produced by the reaction of glycol and an isocyanate. It is moisture- and corrosion-resistant. Consequently, polyurethane is useful as a heavy-duty adhesive, sealant, and caulk. Polyurethane caulk can be applied with a caulk gun. It is available in tubes that will fit the common caulking gun.
Not only is polyurethane caulk noted for its resistance to moisture, chemicals, and corrosion, it provides excellent flexibility. When joints expand and contract, polyurethane caulk is flexible enough to resist cracking and loosening. Polyurethane caulk is available in industrial strength which requires careful mixing of ingredients before it can be used. It is also available in a consumer-friendly ready-to-use form that requires mixing before it can be used.
Silicone Caulk
Silicone caulk is another kind of caulk, but it is different from polyurethane caulk. Unlike organic polyurethane caulk, silicone is inorganic. Being inorganic, it will not break down under prolonged exposure to the UV rays in sunlight and extremes in temperature. The lifespan of a joint sealed with silicone caulk is over twenty years, but a polyurethane-sealed joint will only last about five to ten years.
Silicone caulk is prized for its elasticity and it adheres well to any smooth surface except wood. It is ideal in bathrooms, kitchens, laundry rooms and any room with high moisture levels because silicone caulk is water resistant. You can also get a silicone caulk that contains a fungicide (for use in bathrooms and other areas not used in food preparation).
