Types of Roofing - Configuration Calulations

How many shingles do we need?

Determine the number of roofing squares you house has.

A roofing square is equal to 100 square feet.

1. Seperate the house into rectangle areas.

2. Find the Length in feet of each plus the overhang, usually about 2 feet more than the outer walls.

3. Find the Width in feet of each plus the overhang, usually about 2 feet more than the outer walls.

4. Multiply this Length and Width figure for each rectangle area.

5. Add the rectangle square footages together. This would be the roof area in square feet if you have a flat roof.

6. Multiply the area by the slope factor for your roof (see below).

7. Divide the square foot by 100 to get the # of squares (925 square feet = 9.25 squares).

Slope Factors:

2 in 12 multiply by 1.02

3 in 12 multiply by 1.03

4 in 12 multiply by 1.06

5 in 12 multiply by 1.08

6 in 12 multiply by 1.12

7 in 12 multiply by 1.16

8 in 12 multiply by 1.20

Ridge Cap:

It takes 1 square of Reinke Shakes will cover 96 feet of ridge or hip.

For Geodesic Domes:

A rule-of-thumb is "Diameter" times "Diameter" times .015 This will equal the number of squares you need.

If your dome has extensions, use the standard roof formulas from above, and add it to the basic dome.

Example: 35' dome = 35 X 35 X .015 = 18.375 so, 18 1/2 squares will be close.