Common Building Blunders
Building inspectors and energy raters shared with BUILDER online the top complaints about common “construction sins,” from improperly installed ductwork to leaky windows. Here are a few blunders that made its list.
1. Attic ductwork: Inspectors – particularly those in hot, humid southern states – say they’re always taken aback when they see HVAC pros installing ductwork in the attic. For the new home, ducts in the attic rather than inside a conditioned space can increase cooling costs for a home owner by an estimated 15 percent. Temperatures in the attic can reach up to 150 degrees F on some summer days and the inspectors say they can’t understand why HVAC pros would want to run cool, conditioned air through that part of the house. Building scientists at the DOE’s National Renewable Energy Laboratory agreed in their report, “Ducts in the Attic? What Were They Thinking?”
2. Wrong-sized HVAC equipment: Another blunder builders in hot climate often make is allowing HVAC contractors to install oversized air conditioning units. “Air conditioners that are too large for a home don’t run long enough to provide dehumidification, which can lead to a damp and moldy house,” according to an article by Energy Vanguard. The more insulated the home, the bigger the problem, too; those homes don’t require as much cooling.
3. Little or no air sealing: Inspectors also said they were often disappointed when checking the air sealing on new homes. They say they often find not enough sealant at the top of windows, fiberglass insulation used as an air sealant, or no seal around key areas like doors, band joists, top and bottom plates, and ceiling penetrations. “Having proper air sealing is critical for performance,” says Steven Armstrong, a North Carolina–based home energy rater. New energy codes that are more stringent may soon force builders in more states to pay attention to air sealing in homes, according to the BUILDER article.
4. Conventional crawlspaces: Traditional crawl spaces can expose a home to moisture and mold problems that can wind up creating costly repairs for home owners. The solution, according to inspectors: a sealed, conditioned crawl space with a vapor barrier protecting the under-floor space from ground moisture and with the insulated thermal boundary moved from the framed floor to the wall perimeter. These can provide better humidity control, reduce heating and cooling costs, protect hardwood floors above from warping, and also provide clients extra clean storage space, says Todd Usher, a builder in South Carolina. The Home Innovation Research Labs, along with the Southern Forest Products Association, offers educational materials about the ways to improve existing closed crawl space design.
Source: “Building Inspectors’ Top Nine Construction Snafus,” BUILDER (Aug. 11, 2015)