Sealants may seem like a small detail, but they’re one of the most critical components in protecting a building from air and water intrusion. Whether you’re sealing expansion joints, curtain wall perimeters, or glazing systems, a properly installed sealant keeps the building envelope intact. But sealants have a service life and knowing when it’s time to replace them can prevent costly failures. According to Pecora Corporation’s Sealant Installation Manual, there are several clear indicators that your sealant may be due for replacement.
The first and most common sign is visible cracking or crazing. When a sealant becomes dry or brittle over time, it begins to crack, signaling that it has lost its flexibility and can no longer accommodate movement. This is often a symptom of general aging. In addition to cracking, you may notice the sealant peeling away from the substrate. This kind of adhesion loss is typically caused by poor surface preparation, missing primer, or contamination during the original application. Once adhesion is compromised, so is the joint’s integrity.
Another key indicator is cohesive failure, which occurs when the joint undergoes more movement than the sealant can handle. In this case, the sealant splits within itself rather than at the bond line. Often this means the original sealant wasn’t designed for the actual movement of the joint, and a higher-performance option, like a Class 50 silicone, should be used for replacement. Similarly, if joint movement occurs too early in the cure cycle, especially during drastic temperature swings, it can lead to surface wrinkling or cracking. This premature failure might look minor but can lead to long-term water infiltration issues.
Improper joint design also plays a role in sealant failure. If there’s no backer rod or bond breaker tape in place, the sealant may develop three-sided adhesion. This restricts its ability to flex properly and increases internal stress, often resulting in early failure. In some cases, the sealant may appear to be properly installed but still doesn’t perform as expected. This is often due to incompatibility between the sealant and surrounding materials, leading to poor bonding or staining. Pecora recommends laboratory or field adhesion tests to verify compatibility and performance before application.
Even in the absence of obvious damage, sealants eventually reach the end of their service life due to environmental exposure. UV rays, moisture, temperature fluctuations, and pollution all contribute to degradation. If your sealants have been in place for over a decade, it’s wise to have them professionally inspected, especially in critical areas like window perimeters, joints on facades, or pedestrian traffic zones.
Replacing sealants isn’t just about fixing what’s broken, it’s an opportunity to upgrade your building’s performance. With a wide range of high-performance solutions, including Pecora’s Non-Staining Technology silicone and their hybrid STPU options, you can select the right product for your specific application and environment. When paired with proper joint design, surface prep, and priming, these products help extend the life of your building envelope and reduce future maintenance.
If you suspect your sealants are nearing the end of their life, or if you just want peace of mind, consider reaching out to Pecora’s Technical Service team. Their comprehensive Sealant Installation Manual and support tools can help guide your restoration or replacement project to long-term success.
For more information, please reach out to our Technical Services Department at techservices@pecora.com or 215-799-6234
