Attic insulation improvement in Wilmington, DE
Challenge
Many companies sell home energy upgrades such as attic insulation, replacement windows and doors, and crawlspace encapsulation. However, few follow established building science principles. Instead, they take shortcuts that don’t achieve the desired results, and in some cases, these measures actually create additional problems for the homeowner in the future.
Consider this home in Wilmington, DE, as a prime example. A previous contractor offered a low-cost insulation upgrade by blowing loose fiberglass insulation directly overtop previously existing fiberglass batt insulation. While this might seem like reasonable approach. But building science has clearly shown that upgrading attic insulation without first sealing the attic floor is a mistake. Without proper sealing, conditioned air from the living spaces below can be drawn up into the attic where it ultimately escapes into the outdoors. This is a costly waste of energy and the money this home owner was paying to condition that air.
Lawson Home Services’ energy auditor and crew discovered several issues that a trustworthy home energy upgrade company would prioritize fixing. For instance, they found a bath fan that ended in the attic, just below the roof deck. Bath fans release warm, moisture-laden air. When that air meets the cold underside of the roof deck in the cooler seasons, it turns into water droplets that are then absorbed directly into the wood. Mold typically appears, and eventually the roof deck begins to rot away. Repairing a rotted roof deck is very costly.
Solution
In the past, and even some cheaply constructed modern homes, construction practices have often left openings in the attic floor. These openings include gaps in the drywall at the tops of walls, lighting fixtures in ceilings, electrical wiring and exhaust fan vents. These are the places where air leaks from the living spaces below leaks into the attic.
When upgrading attic insulation, it is crucial to remove the existing insulation to reveal these opening where air escapes.
In this particular case Lawson’s crew had to not only take out the original fiberglass insulation, but also the new insulation that had been added on top.
Once the attic floor was thoroughly cleared, workers begin the process of identify and sealing the openings usind Zyp™ expanding foam.
The bathroom fan, which was contributing to mold growth on the underside of the roof deck, was properly re-routed through the roof deck. This way it vents the warm moist air directly into the atmosphere outside the attic.
