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Replacing a building’s exterior sealants

This often overlooked component is critical to maintaining a healthy building envelope
Wednesday, June 18, 2014
By John Margaritis

Whether a condominium is a townhome or a high-rise, replacing exterior sealants before they fail is one of the most important contributors to maintaining a healthy building envelope. An estimated 90 per cent of air and water leakage occurs at one per cent of a building’s sealant locations (i.e. vulnerable sites such as terminations, transitions and penetrations). Making sure that this one per cent of a condominium’s exterior is properly sealed is critical.

Despite their importance, exterior sealants are also one of the least understood and maintained components of a building envelope. The simplest explanation for this might be that sealants are, for the most part, out of sight and therefore out of mind. This is especially true for high-rise condominiums, where much of the sealant is not visible from the ground.

Sealants also have a long replacement cycle — 12 to 20 years, depending on product and environmental exposure. Many changes are likely to take place at a corporation over that timeframe. Board directors and property managers may come and go; a reserve fund study may recommend a sealant replacement project, but higher priority projects may have to be moved ahead of it. As a result, a condominium’s caulking and sealant needs may get lost in the shuffle.

Unfortunately, sometimes it takes water penetration damage to multiple condominium suites or townhomes to get board directors and property managers thinking about caulking.

Due to sealant’s long life cycle, property managers and board directors may lack experience initiating and overseeing a sealant replacement project. Add in the technical nature of the materials and techniques involved, plus health and safety considerations (especially with high-rise work), and the whole prospect can be overwhelming.

Here are a few tips for getting started:

1. Determine when the last time the building or townhome site was caulked. If past the 12 to 20-year mark, water leaks, wood rot, or other damage may have already begun to occur.

2. Determine whether the site has been over-beaded or all old sealant was removed prior to caulking. Over-beading should only be done once. If a site has already been over-beaded, then full removal is required. If not, then over-beading on failing caulking is an economical option.

3. Determine the type of sealant currently in use on site. Inferior products may mean a shorter life cycle.

4. Make sure all stakeholders understand the specification and any possible limitations of the sealant system proposed for the replacement project.

5. Find a qualified contractor. A contractor’s warranty will cover only a small fraction of the expected life of the sealant, so try to work with someone known and trusted. Also ask to see the contractor’s Health and Safety Plan. High-rise sealant replacement projects require specialized health and safety expertise and management.

Realizing that sealant replacement projects can be costly, property managers and/or board directors should avoid letting price dictate their decision when choosing a contractor or sealant system. Savings realized today are only true savings if the selected sealant system performs for 12 to 20 years. Poorly installed sealants may lead to spot repairs year after year, quickly reversing any savings that may have been generated by proceeding with the contractor with the lowest price.

Sealants may only account for an extremely small percentage of building construction, but building envelope repair and replacement account for significant spending. So whether a condominium is a townhome or a high-rise, it’s important to remember that sealants might be out of sight, but they should never be out of mind.

John Margaritis is a senior project manager with CPL Group: a refurbishment and painting firm based in Oakville, serving the GTA and Golden Horseshoe condominium marketplace for over 20 years. 

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