“Should I re-caulk a few leaky windows or opt for a full system replacement?”

By Scott Parello, VP, Exterior Building Services | May 13, 2014


These past few weeks Maryland, DC, and Virginia saw a copious amount of rain, some of it reaching record-setting totals. Whether the effects of the rain and flooding on the Baltimore-Washington metro area’s structures exposed an immediate need for building repair or reminded you to take preventative measures, replacing joint sealants on commercial structures is an important maintenance procedure in the preservation of the exterior envelope of the building.

The question on many property managers’ minds is “Should I re-caulk a few leaky windows or opt for a full system replacement?” Unfortunately, this is not an easy question to answer. It really depends on a number of variables.

We understand keeping your tenants happy is of the utmost importance. And if a tenant has a leaky window, you may not have time to do a full system replacement. At PCM we offer both services and would be more than happy to work with you to decide which solution is in the best fit for your particular building and tenants.

Let us give you some insight into our decision process:

First, we consider when your building’s joints were last caulked and whether the current sealant is silicone or polyurethane. While both are successful at keeping water at bay, the two sealants can have different lifespans. For example, assuming proper design and installation, a polyurethane joint’s lifespan is typically 5-10 years, while a silicone joint’s lifespan is typically 20+ years.

Why is there such a big difference? Simply put, at the end of the day, a silicone joint’s lifespan is longer because, chemically, it won’t break down. Like UV light, temperature plays a role too. Silicone is better suited for temperature extremes. This is especially important in the Mid-Atlantic where we have some of the most dynamic thermal cycles in North America. Changes in temperature cause the joints to expand and contract. Typically, the more flexibility the sealant allows the better. Silicone allows for greater movement if that’s what’s necessary.

What does this mean for the owner? For a full system replacement (replacing all external sealants on all elevations), most manufacturers of polyurethane offer a 5-10 year warranty. From a silicone manufacturer, you can typically get a 20 year warranty. Full system replacements can be done all at once or through a multi-year phased approach depending on your building and budgetary needs.
So, should you re-caulk a few leaky windows or opt for a full system replacement? Ultimately, the decision comes down to how long you are planning on maintaining the building. Some warranties are transferable to the new property owner. That being said, these warranties are typically not available when single windows are caulked.

Still unsure what the best fit is for you? No problem! Give us a call at (301) 595-3700. We’ll send one of our experienced Exterior Building Services estimators out to evaluate your building and offer his recommendations. We’re here to make your life easier.