## 757-963-6878

###### Virginia Class a builder lic# 2705158280

COMMITTED TO SERVING HAMPTON ROADS  NORFOLK - VIRGINIA BEACH - CHESAPEAKE - SUFFOLK - PORTSMOUTH - HAMPTON - NEWPORT NEWS

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NOTE: This works for hip and gable roofs.

Calculating Roof Area from Plans

1. Add the overhang to dimensions.
2. Multiply Length by Width.
3. Multiply the area by the rafter multiplier that corresponds with the roof slope of your plans.
4. Divide by 100 to calculate the number of squares.

Calculating Common Rafters on Hip / Valley

1. Measure the run (Flat dimension).
2. Identify the multiplier that corresponds with the roofs slope.
3. Multiply the run by the multiplier.
4. Round to the next "even" number.

RAFTERS

Example: What is Square Feet in the Gable Area of a 50' wide building with a 12' Gable Height?

1. GA = Gable Height x Run ÷ 2
2. GA = 12 x 25 ÷ 2
3. GA = 150 SF

Example: What is the run of a building that has a 60' run? The Slope is 6:12

1. Run = 60 ÷ 2
2. Run = 30
3. GH = Run x Vertical Rise
4. GH = 30 x 6
5. GH = 180" (or 15')

Example: What is the run of a building that has a 50' span?

1. Run = Span ÷ 2
2. Run = 50 ÷ 2
3. Run = 25

Calculating the Gable Area of a Building

GA = Gable Height x Run

Calculating the Gable Height of a Building

GH = Run x Vertical Rise

Calculating the Run of a Building

Run = Span ÷ 2

Gable Calculations

Gable Height

Coverage Area per Roll of Felt (Underlayment)

1. 15# Felt Underlayment  400 SF
2. 30# Felt Underlayment  200 SF

Waste Factors

1. Simple roofs (Gable) ---1 - 5%
2. Complex roofs -----------5 - 10%
1. Measure Height from the bottom of the roofline to the ridge board.
2. Measure the Building Length ( include the overhang )
3. Multiply Length by Height for the area.
4. Divide total area by 100 ( this is the number of squares required )
5. Multiply the squares by the number of bundles per square ( or see the table Below, or manufactures instructions for quantity )

Calculating Bundles of Roof Covering