When it comes to building envelope integrity, testing starts early
Davis Reeves, Paladin, Inc.
When finely-tuned environmental control systems meet an air-tight building envelope, great things can happen in terms of a building’s operating budget, occupant comfort and owner satisfaction. While the bulk of building envelope testing is traditionally conducted after the structure is mostly complete, there are a number of tests that can be done earlier in the construction timeline to allow fixes in real time. Building owners who want best results should get familiar with system checks like an air infiltration test.
Working for a commissioning engineering firm, I’ve tested countless buildings (actually, I know EXACTLY how many buildings I’ve tested, but I’m not given to bragging or sharing my employer’s proprietary information) and seen certain problems repeat themselves for builders. When it comes to air tightness, the seal around doors, windows and utility penetrations are obvious places to look for leakage. However, there are other problem spots that can be challenging to find and fix if they’ve already been covered by an expensive finish.
That’s why our team at Paladin advocates for early and ongoing air infiltration testing. As soon as an exterior wall or roof is in place and the air barrier coating has been applied, we can roll in with our equipment to spot test its impermeability and recommend a fix before a repair requires too much delay or destruction of expensive materials.
We use DeFelsko’s PosiTest AIR, a device that wouldn’t look out of place in a Ghostbuster’s movie with its polycarbonate dome, flex hose and testing unit. We apply a soapy solution to the test area then use the dome to cover the suspected point of leakage. With the flick of a switch, the PosiTest depressurizes and issues a pass/fail indication if air leakage is detected.
Over the years, we’ve found air leaks in a variety of locations including the points where two different surface types are joined or masonry ties have been improperly sealed. We have also helped some builders discover that their sealant application equipment isn’t working properly. In these cases, issues were resolved and the construction process stayed on track. Had our customers waited for the project’s end to start the testing process, it could have been much more expensive.
When a building project draws to a close, we still show up, ready to pressurize and depressurize the entire building using high-powered, calibrated fans to find out if air is entering/leaving in ways it shouldn’t. We also do thermography testing to pinpoint trouble spots. When we’ve done ongoing air penetration testing, the results are much more in line with levels needed to attain compliance with energy standards.
At the end of the day, true control of energy efficiency is best attained when the movement of air into and out of a building can be managed. With careful, ongoing testing as a building comes together, the odds of taking control of this key challenge rises to the point of making a real difference in the economics of a building.