For centuries, people have used natural material to fill the gaps between all kinds of structures. The first synthetic polymers were developed in the 1930s, and the residential caulks now come in five common types, according to their chemistry.

Versatility and efficiency

The polyurethane caulk is based on the reaction between glycol and isocyanate and it’s generally the best choice for outdoor applications. It’s highly durable and often used instead of silicone caulk. A versatile sealant, it has the ability to adhere to a number of materials, which makes it excellent for creating seals between surfaces.

Here’s the 5 main advantages of polyurethane caulking:


Its versatility is perhaps its greatest benefit. The polyurethane caulk can be used on plastic, concrete, wood, metal, and glass. It also adheres very well to vinyl siding, aluminum siding and brick. The only thing you should be careful with is polycarbonate plastic.


The reason why the polyurethane caulking sticks so well is because it actually bonds to the material on a molecular level. It also has an unmatched stretching ability – elasticity up to 300% or more – which is useful if you’re going to apply in on materials, expected to expand and contract on a regular basis.


It’s also extremely durable – the seal can last up to 10-20 years, depending on the exposure. It’s also paintable and water-resistant which makes it an excellent choice for a variety of jobs and materials. Since it’s solvent-based, you need to use paint cleaner when cleaning it up. It can also be a little stiff and toxic and that’s why it requires extra caution, when handling.


However, the polyurethane caulk offers unmatched adhesive strength, elasticity and can hold up to any heavy movement. Apart from that, this ultimate sealant can also be painted easily and is great for filling indoor, as well as outdoor gaps.


Pro Bob is an experienced contractor and renovation specialist, who loves to share his know how with others.