The undead are among us ... ask any teenager. The ghoulish unliving return from the crypt to devour our innards and they must be driven back into the grave. We have our own building-performance–specific zombies that arise from our projects to devour our innards and spill the lifeblood of our bank accounts. They lurk in the details that we overlook, don’t think are important, or just plain don’t know about. Many are the ways that our projects must guard against these fearsome predators.

Where the Undead Gather

Mold grows on manufactured building materials, like OSB and paper-covered drywall, that are not protected from liquid water, and zombies can live in mold.

They can live in poorly flashed window and door openings, waiting to be revived by the water leaking into their hiding places. When no kick-out flashing protects a vertical wall intersected by roof eaves, you can hear the zombies anticipating a hearty meal.

See the stain on the siding? That’s zombie drool.

Zombies live in other cunningly hidden details of building performance: insulation installed without air sealing; windows installed with fiberglass scraps packed between the jambs and the rough opening; entrance and patio doors installed without sill panning; bath fans chosen because they’re cheap instead of effective and then left vented into the attic; unsealed cold-air returns; buildings tightened without regard to fresh air or possible radon; a poly vapor behind the drywall in a hot, damp climate.

Other zombies thrive on contractors and homeowners who don’t understand that burning natural gas (or oil, or kerosene) in furnaces, water heaters, space heaters, and gas ranges is downright dangerous without careful attention to venting.

You don’t light a wood fire inside your house unless it’s under a chimney that works. Now imagine a wood fire with no visible particulates in the smoke. That’s pretty much what you get when you burn other fossil fuels. Zombies want you to keep that vile stuff inside, where you have to breathe it. It brings you closer to their nasty, shadowy world.

—Ed Voytovich is a principal at Building Efficiency Resources. Reach him at   

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