What Is the Cheapest to Build: a Gambrel Roof or a Gable Roof?

A roof with two pitches, one steep and one shallow, the gambrel roof is generally more costly than a gable roof.
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When you compare the "Dutch barn" look of a gambrel roof with the traditional, suburban, gabled — or pitched — roof, your choice might come down to price. While the differences in cost between the two aren't huge, the gable roof is generally less expensive, as it typically uses fewer materials and has lower labor costs.

Expert Estimate

Danny Looper, a commercial sales manager for Lowe's, in Cookeville, TN, notes that "a gambrel roof costs between 15 and 20 percent more than a gable roof." This means that, if it will cost $10,000 to build a gable roof, it will cost between $11,500 and $12,000 to build a gambrel roof for the same building. And that difference only tends to get larger with size: "The larger the house is, the greater the percentage," says Looper.

Gable Roof Basics

The gable roof, now often used by developers because of its low construction cost, is found on most homes in America. It's a variation on the shed roof (which is a single roof panel that's slanted to shed water and snow). Instead of a single panel, two panels, both slanting downward from a common edge, form the gable roof. The common edge, called the "ridge," is the highest part of the gable roof. The two panels that form the gable roof are supported by rafters and attached to a beam beneath the common edge called a "ridge beam." The roof is covered with a roofing material of shingles, wood, metal or tile. To ensure water or snow doesn't penetrate the common edge, a "ridgecap," a single line of the same roofing material that covers the roof, covers the ridge from one end to the other.

Gambrel Roof Basics

Like the gable roof, the gambrel roof type has a historical basis. In the early 1600s, Parisian tax assessments included the number of a home's stories facing the streets. Architect Francois Mansart created a type of roof that camouflaged a home's second story behind a layer of shingles. England adopted a similar tax, on the windows for a disguised second story, in 1695. To avoid this "window tax" while maintaining the convenient head room of the Mansart (or "mansard") roof, English builders adopted the gambrel roof, both at home and in the Colonies. That's how the gambrel roof found a home in America.

Materials & Labor

The gable roof has triangular rafters, with interior supporting members that sit atop of the walls of your home. It has a single pitch. "Pitch" is the ratio of the change in the roof's height, in inches, to each 12 inches along the horizontal base of the rafter. For example, if the roof rises 4 inches for each 12 inches of run, the roof's pitch is 4/12.

The gambrel roof has two pitches — the steep pitch of the part of the roof that rises from the walls and may enclose a second story; and a shallow pitch, flatter than the initial, steep pitch, where the sides of the roof come together at the ridge. These rafters involve more material than the simple gable roof, which is one of the main reasons for the extra expense. Looper also notes that roofers often charge more for a gambrel roof not only because of extra labor to construct them, but also because of increased danger of falling during installation due to the extreme pitches.

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