Worried about air tightness tests?
You have probably heard the horror stories – a builder commits to building a super-efficient house. Maybe it’s going to be Energy Star rated, or maybe it’s R-2000, or maybe it’s something more elaborate. They get the house ready for occupancy but then they fail the final step in process. They’re unable to pass the air tightness test. Hours of detective work and dozens of repairs later, the builder achieves a “Pass” but vows, I’ll never do that again!”
Even the most experienced low-energy builder can sympathize with the perils of passing that all-important air tightness test. There are a number of reasons why it would be good to know the outcome of the test well before the completion of construction. Yet even today, many builders rely on a sealed polyethylene air barrier—a system that requires attention to detail, needs drywall in place to support the poly (especially during the air tightness test,) and the air barrier can be easily damaged by finishing and other trades. It can be a very risky proposition.
Are there Other Alternatives?
- Some fibrous insulation manufacturers offer spray-on latex sealing systems that can be sprayed into wall cavities before insulating to compartmentalize and air seal exterior walls.
- In commercial construction, exterior air barrier systems have become the norm. This is due to architects recognizing the fact that an air barrier oriented towards the exterior of a wall assembly can act not only as a barrier to air leakage but water leakage as well.
- Finally, an increasing number of builders are using spray foam, either on the interior in wall cavities, or on the exterior as continuous insulation and air barrier to simplify construction and allow them to take the work of insulating and air sealing and consolidate these tasks into the work of one sub-trade—one contractor—one person responsible to get the job done properly. Having made this decision, it becomes easy to air test the house, immediately after air sealing and spray foaming, to verify that the air tightness target has been achieved. No more waiting until the home is completed to carry out the air tightness test.
Making a commitment to airtight building construction is an opportunity for leading builders to differentiate themselves. Furthermore, airtight construction can have some unexpected benefits including: more even heating and cooling loads in the home, less risk of frozen pipes, fewer drafts and fewer call-backs.
If you take advantage of an air barrier system that can be tested and verified at an earlier stage of construction, you can add another key benefit. You can minimize the risk of not passing the air tightness test at the end of the construction process. You don’t have to wonder: “Will I need to rip out that bathtub?” to fix an air tightness defect that’s hidden in behind it.
The growth in popularity of spray foam and other non-polyethylene air barrier approaches is a pretty good indicator that many builders are looking beyond R-value when they consider how they build high performance houses.
The spray foam experts at Bolivar Insulation Company are a reliable source of information when planning an energy efficient build. For more information, call Bolivar Insulation at (417) 862-6223 or visit the Bolivar Insulation website at www.bolivarinsulation.com
This post brought to you by Bolivar Insulation