Sealant Types

How would you decide which sealant type is best for different uses. For example, what sealant type would work best in a place where is a lot of movement? Or where there is higher chance of water getting in? Tagging @coachadamcoers

So when it comes to sealants there are 7 types that are most commonly used in construction: Latex, Acrylic, Butyl, Polysulfide, Silicone, Polyurethane, Polyisobutylene. Each of these have unique properties that make them suitable for different applications.

Latex sealants are paintable, easy to clean up, adhere to most substrates, and are less expensive than other options; however they are prone to shrinkage and are best suited for interior finish applications where gaps are small and movement minimal.

Acrylic Sealants are also paintable and low cost sealants that are UV stable allowing them to be used in commercial and exterior applications as well as having a capability for limited movement. However the application is somewhat more difficult compared to a latex sealant.

Butyl Sealants provide strong adhesion to multiple substrates and are commonly used in curtain wall systems where adhesion to rubber materials is needed. However they are a little bit higher costs, difficult to apply and provide poor abrasion resistance.

For underwater applications, Polysulfide sealants are a common solution. These sealants are water, chemical, and UV resistant and provide flexibility even at low temperatures. While these sealants typically have a life expectancy of 10 to 20 years, they do require a primer, may have higher levels of VOC’s and are a higher cost than other options.

Silicone sealants also are UV and thermally resistant sealants with the highest movement capability. They are flexible with good adhesion and a long service life. However, they do have a high cost, a strong odor and long cure times. They also are not paintable and can produce staining to certain substrates so applications could be limited.

A good alternative to silicone sealants are Polyurethane sealants. Polyurethane sealants are a durable,paintable, and abrasion resistant option that adheres well to different substrates with little prep with a high movement capability. However these also have a high cost, are difficult to apply and tool, and cannot be used in glass assemblies.

The last option, Polyisobutylene sealants, are usually factory applied and are used as the primary seal for Insulated Glazing Units. These sealants are also durable, chemical resistant, and have a low permeability.

Selecting the right sealant can always be a trick, but it all comes down to evaluating the desired performance properties and selecting the best product for each application. Many of the different sealant manufacturers such as Sika and Tremco just to name a few provide resources to assist in the selection of their products based off of different conditions.

Hope this helps!

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