Behind the drywall

Drywall hangers work in the great room of a new home under construction. While house wrap is a home's exterior skin, drywall is its interior skin. The generic term encompasses many products. Behind the drywall is the house's skeleton or frame. (Blooomberg Photo)

Homebuilders spend a bundle dressing their model homes so you are seduced by their sectionals and wowed by their wallpaper. What's behind the walls, though, is what determines if a house is best in show or just for show.

True, "they don't build ‘em like they used to." You can no longer find a new house framed with knot-free lumber, as in the old Sears houses. But, on the plus side, you cannot find one that's laced with asbestos or lacks insulation. Not if it is built to code, that is.

The state's new Energy Efficient Building Act says new houses must meet the International Energy Conservation Code (IECC). "Most high-end builders already do this," explains Mark Perlman, president of Empeco Custom Builders in Northbrook. "But this forces production builders to meet higher standards, too."

In addition, builders must comply with city and county building codes, which primarily address safety issues. Within these parameters, though, the bones of new houses vary greatly.

Compared to their Swiss-cheese-like predecessors, today's homes are "tight envelopes," say the builders. A diligent builder caulks and seals every opportunity for heated air to escape.

Keeping the house's frame dry is house wrap. "Even at entry-level price points, buyers expect it and should get it," reports Jeff Benach of Lexington Homes in Chicago.

The skin

If house wrap is the exterior skin, drywall is the house's interior skin. But "drywall" is a generic word that encompasses many products.

"We use QuietRock, which has a higher insulating value and deadens sound more than ordinary drywall," says Patrick Shaver, director of sales and marketing at Century Bay Builders in Libertyville. "It costs a little more, though, so you can at least use it for bedrooms, media rooms and other rooms you want to keep quiet."

Standard drywall is a no-no in bathrooms. "Bathroom walls should be made of greenboard, which is water-resistant drywall," explains Shaver. "Behind showers and tubs, you have cement board, which is waterproof."

The bones

Behind the drywall is the house's skeleton or frame. While a handful of builders use metal framing, most still use wood.

"SPF (spruce/pine/fir) is the standard," reports Ed Kubiak, director of construction, Beechen & Dill Homes Inc. in Burr Ridge. "Hemlock is cheaper but shrinks more when it dries, so the result is inconsistent."

For floors, Kubiak prefers engineered wood. "OSB [oriented strand board] is the cheapest but can swell with moisture," he explains. "Plywood is better. But we use engineered wood that's sealed on six sides, so it doesn't absorb moisture. It costs more but won't create a squeaky floor."

Beware the builder who buys the cheapest wood at the lumberyard, which is warped, full of knots and/or moldy. "With the housing slowdown, the lumberyards have wood that's been sitting out," says Kubiak. "A good contractor won't buy it."

Most builders use 2-by-4 studs for walls, says Westmont architect Bill Styczynski, although walls taller than 10 feet tall require 2-by-6 studs for strength.

The home shopper should consider not only the size of the stud, says Styczynski, but the distance between them. "Sixteen inch on center" means there are 16 inches from the center of one stud to the next. Some builders use "24 inch on center." Combined with the stud size, it makes a difference, says Styczynski. A 2-by-6, 24-inch-on-center wall minimizes framing costs and offers more room for insulation, he explains, but squeezes a few inches out of the width of the house, which matters on a small lot.

The fat

Between the studs is cavity insulation. Like the fat on our bones, it keeps the house warm. (Or, in the summer, cool.)