Building for Indoor Air Quality

The issue of indoor air quality and overall building health is becoming more prevalent than ever. With building standards such as LEED being updated to include points awarded for healthy indoor air, builders must consider how to create structures that balance function with health. There are many products on the market that tout contributions to air quality, but during construction indoor air quality involves much more than individual products.

We spoke with Neil Freidberg, Building Science Manager at LP, to get his take on the importance of indoor air quality and how LP Structural Solutions products, such as LP WeatherLogic® Air & Water Barrier, can help contribute to healthy indoor air.

Building Health Defined

Building health refers to the measure of a structure's ability to perform as intended without negative impact on its inhabitants.

"Building health in general is much more than an envelope," Freidberg says. "Walls, however, need to be structurally sound and have the ability to dry in both directions and prevent bulk water from entering a home." These factors contribute to the structure's ability to perform as it was designed.

Healthy Indoor Air: Homeowner Perceptions

When homeowners think of healthy indoor air, they may think of the primary ways they can feel air coming and going through their homes: doors and windows. However, Freidberg points out, there's much more to indoor air quality than what can be seen and felt (though opening doors and windows does bring in unwanted allergens).

"Air sealing starts with the framing," he says, "and it sets the boundaries of your building envelope." Any air that hits the home on its exterior can get inside the home through many small gaps and openings if they are not properly sealed. For example, anything held up inside the walls-insects, dust and more-can enter inside the home. However, the effects of these small gaps and cracks aren't as easy to notice compared to pollen that enters an open window and causes the homeowner to sneeze.

Freidberg offers a quick tip for builders to communicate to their clients that will help them test for unseen gaps: “Spiders like to find drafts because they can count on bugs coming in. If you have cobwebs, there's air moving through a crack or hole somewhere nearby.”

Controlling Indoor Air Quality

Many clients may think that filters and other comparable products can do the job of maintaining healthy indoor air, but building professionals can offer a more complete view of how to approach the quality of air inside their structures.

Freidberg points to air change per hour (ACH) levels as a guide. ACH refers to the number of times the total air volume inside a structure refreshes per hour. Current codes vary, but an ACH level of three to five times per hour is generally standard-the lower the level, the better the structure's air sealing has been completed. ACH can be lowered by tightening a building's envelope and reducing air infiltration paths.

"When ACH is low, you can truly begin to control air quality," Freidberg adds. If the structure has a solid base level of air quality, filters can be used most effectively to bridge the gap and clean any remaining air that does come in through HVAC units.

This also leads to energy efficiency benefits. "The same cracks that bring in air also bring in moisture," Freidberg says, "which means HVAC units have to run longer to pull moisture out of the air." The tighter the house, the more efficient a home's HVAC unit becomes.

The System Approach: LP WeatherLogic Air & Water Barrier

It takes more than one product to achieve indoor air quality, but LP WeatherLogic panels help you lay the groundwork for your structures. "LP WeatherLogic panels set the proper boundaries for a tight building envelope," Freidberg says, "and provide both structural integrity and moisture management."

As Freidberg mentioned, for walls to contribute to building health they must have a few necessary characteristics, and LP WeatherLogic panels check all the boxes. For example, the panels are Structural I rated for greater cross-panel strength and stiffness. They also help safeguard homes from water while allowing moisture vapor to escape. Finally, they're proven to seal out both moisture and air when paired with LP WeatherLogic Seam & Flashing Tape, helping contribute both to energy efficiency and the home's indoor air quality.

The Future of Building for Indoor Air Quality

As LEED and WELL Building Standards adapt to changing concerns among builders and homeowners alike, new solutions must be considered. "These changes are already happening," Freidberg notes, citing commercial buildings' steps toward better health, including removing formaldehyde and high VOC interior paints. "Commercial spaces started the trends, and residential homes will gain from that as we're spending more time indoors than ever," he says.

The Importance of Maintaining Clean Air

Clean air, of course, contributes to the health of the individuals living inside a structure. When our air is clean, we can live better overall. With deeper concerns rising, especially in the wake of the COVID-19 pandemic, cleaner air has never been more top-of-mind for builders and their clients.

Freidberg suggests that builders communicate with their clients in terms of needing a total solution for air quality in their homes-not simply one product. "Regardless of what's comfortable for each family, when you build an air-sealed, energy-efficient home it can withstand any environment the homeowner chooses," he says. "You have to look at it holistically-how things interact with one another. If not, you'll be missing out on potential benefits."

Interested in learning more about LP WeatherLogic panels and how they can help you create tighter building envelopes? Check out our most frequently asked questions here.