Certainteed Self-Test Section 3

The roof area of a gable roof is made up of two rectangles.

Roof area can be broken down into three basic shapes: rectangle, triangle, and trapezoid.

The slope of a simple gable roof may be defined as.

If you know the rise and the run of the gable roof, you can calculate the rake length and area using slope factors.

If we project the area of a hip roof onto a horizontal plane, it will appear as two triangles and two trapezoids.

You can determine the slope of a roof using a flat board, a bubble level and a ruler, or a sight card can be used.

If a hip roof has a slope of 6 inches per foot (hip slope factor = 1.5) and a hip run of 14 feet, the length of the hip in feet will be:

It is useful to know the length of the eaves directly below a hip. By standing on the ground and using a plumb bob, you can find a reference point on the eaves for measurement.

On a 1500 square foot gable roof, there will be approximately 11% waste.

A gable roof with a slope of 9 inches per foot has a rake slope factor of 1.25. If the run is 10 feet and the eaves length is 30 feet. What is the roof area in square feet?