Whether you’re designing a new building or conducting regular exterior maintenance, evaluating the effectiveness of a rainscreen system is a valuable skill for both general contractors and their clients. Because rainscreens play a fundamental role in ensuring the longevity of a commercial building, it’s essential to choose a system that functions properly and is easy to maintain over an extended period of time.
Rainscreen failures most commonly occur due to penetrations in the barrier layer or faulty installation practices. To minimize the risks of a rainscreen system failure, following a proper evaluation process is key.
Why Are Rainscreen Systems Important?
Preventing water from entering a commercial building over an extended period of time can be very difficult, and often can’t be accomplished without a rainscreen system. The purpose of a rainscreen is to prevent water and moisture from entering the interior of a building and causing structural issues. Despite its name, rainscreen systems also protect buildings against harmful UV exposure from direct sunlight. Rainscreens are comprised of a cladding layer, a cavity, and a barrier that collectively prevent rain, snow, wind, and ice from damaging the building’s exterior wall.
However, the benefits don’t end there. In addition to simply protecting your building’s exterior, commercial rainscreens help to reduce condensation on the exterior wall, promote air circulation, regulate temperatures, reduce structural movements, increase energy efficiency, and ultimately extend the lifespan of your building’s facade.
Tips For Evaluating The Quality Of A Commercial Rainscreen
Evaluating a rainscreen system isn’t always a straightforward process. Rainscreen system performance varies dramatically depending on the material, the panel system, and whether or not it’s exposed to direct sunlight. While many clients may not be familiar with the specific details of their building’s rainscreen or cladding system, it’s still important to have a high-level understanding of what is being implemented. Below are some important things to consider when evaluating your system.
Recognize The Differences Among Cladding Materials
Rainscreen systems can work with most cladding materials, which allows for flexibility in terms of design and aesthetics; however, this doesn’t mean you should ignore the differences. The cladding material you select will ultimately have an impact on the performance of your rainscreen. Using porous materials, like brick, will allow for better water absorption while wood will most definitely require extra treatment, may deteriorate faster, and may not perform at the same level.
Manage The Gap
Your commercial rainscreen system should have a gap between the outer cladding layer and the remaining portion of the exterior wall. This gap serves a number of purposes. For one, it serves as a gravitational barrier for water that makes its way past the cladding, and it allows it to drain effectively. The gap also promotes airflow which helps to eliminate moisture and prevent mold growth. The more space you can allow, the more air will be able to circulate. If your system has a gap of 1” or larger, you’re definitely in good shape. The gap should also have holes at the top and the bottom. Gaps should be kept clear of insects and debris through the use of screens, corrugated mats, or other materials.
Pay Attention To Barrier Selection & Layout
With most rainscreen systems, thermal, vapor, air, and water are the four types of barriers that protect your exterior wall. It’s always important to consider how your rainscreen system’s layout, attachment method, and exposure impact the barriers, and it’s critical that your barriers are appropriate for your commercial construction project.
Evaluate Performance Track Record
Selecting high-performing rainscreen materials that have proven to be reliable in other areas of your commercial construction project can be a good way to evaluate or predict the performance of a commercial rainscreen system. Selecting materials that have a track record of corrosion resistance, durability, and stability will go a long way towards ensuring your rainscreen and cladding systems will perform as expected.
Focus On Continuous Insulation
Commercial rainscreens that include continuous insulation beyond the primary structural elements is a really good way to improve a building’s energy efficiency. Mineral wool boards placed over your weather-resistant barrier or foam sheathing behind the cladding are good examples of continuous insulation. Incorporating these measures is a good way to reduce thermal bridging, which ultimately diminishes energy efficiency.
Consider Long-Term Maintenance
If your rainscreen system doesn’t allow for easy maintenance and accessibility, it could quickly prove problematic. The lifespan of your rainscreen system and cladding system is generally contingent on its weakest component. If your sealants, gaskets, or flashing have a limited service life, you’ll need the ability to make repairs and keep your system in good shape.
Rainscreens are an incredibly important part of commercial construction designs, so learning to understand their various components and how to evaluate their quality is a valuable skill for both general contractors and their clients. When designing your next commercial building, remember that a good commercial rainscreen is well worth the investment.
If you’re looking for a local California subcontractor that specializes in rainscreen systems, contact us at Unique Building Group today. We have over 30 years of experience managing complex commercial construction projects