The Different Effects of Polyurethane Sealants and Urethane Sealants

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Polyurethane sealants are quick-drying and moisture-cured sealants that are used in many industries including building, construction, and the automotive industry. It is generally used for sealing joints in walls and floors. It works well on concrete, and it also seals and bonds fiberglass panels.


When polyurethane sealant dries, it produces a very tough elastic-type seal. It also seals and sticks well to masonry, wood, and metals. It is highly compatible with plastic and rubber.

Urethane sealant, meanwhile, is a clear interior sealant mainly used on floors like terracotta tiles. Polyurethane can harden much quicker than urethane and it can be used to mend vehicles, especially those made from fiberglass. It seals and mends fiberglass extremely well, creating a very strong bond.


Polyurethane sealant proves to be an excellent resistor of water and ultra-violet radiation. It offers a permanent elasticity in all weather conditions. Urethane sealants are more designed for porous materials such as concrete, slate, and terracotta. It is highly protective in heavy traffic areas and resistant to grease, oil, gasoline, and food splashes.

Indoors and Outdoors

Polyurethane sealant is recommended for decking and flooring because it works better on outdoor and weathered surfaces. It is not at all recommended for use with glass and it is not recommended for use on joints with movement greater than 25%.

Urethane sealant is recommended for indoor use such as in kitchens, restaurants, or warehouse floors where industrial spills are more likely to occur. The fact that it protects against heavy foot traffic also makes it ideal for these areas.


Urethane sealant is available in a caulk form which will seal joints in bathrooms and kitchens. There are many different kinds of caulk sealants and choosing the correct one depends on the individual job and conditions.

Polyurethane sealants also come in caulk form and act almost the same way in which silicone sealant behaves. Urethane caulk will fill cracks and holes in the same way that filler will, but gives a more firm grip to adhere better on most surfaces.


Polyurethane has a much faster drying time and the different effects between polyurethane sealants and urethane sealants can be quite noticeable in this respect.

Urethane sealants need to be left to dry for almost three days while polyurethane sealant is usually dry within 24 hours. This can make a lot of difference on projects with a tight deadline; a slow drying time can cause a halt to a project and really slow down your progress.


Polyurethane is a corrosion-resistant material that can emulate any surface such as plastic or metal. Non-commercial types of polyurethane sealant are usually single component products and require no mixing prior to use.

There are very few different effects between polyurethane and urethane sealants, mainly because they are not that different from each other. The polyurethane material is based on a polymer chemical while the urethane alternative is not.

Their characteristics are actually very similar, and apart from drying time and a few different uses, there is not much to choose between them in terms of differences.