Whenever possible, you should avoid the risk of walking along the eaves of a roof. The CDC reports that more than 150,000 Americans end up receiving medical treatment due to roofing accidents every year. These injuries can be serious, from fractures to brain trauma. Even professionals fall off of roofs, so it’s wise to reduce your risk of accidents as much as possible.
One of the ways you can reduce your risk of accidents is by learning how to safely measure a roof from the ground. Without ever climbing up on the roof, you can learn a great deal about the size and dimensions of your roof.
Let’s start by looking at the materials you’ll need for measuring a roof.
- Tape Measure (you’ll appreciate having a tape measure that is at least 25 feet long. Measuring wheels are also helpful)
- Graph Paper (basic graph paper will help you to draw straight lines and create a drawing to scale)
- Calculator
- Pitch Gage (you can download a free pitch gage app on your smartphone to always have available, or you can use the table below)
With these simple tools available, you’re ready to get started.
1 – Calculate Your Roof Pitch
The pitch of the roof is how steep it is, and this is an important figure to know as you work on your calculations. Pitch equals the roof’s rise over its run.
You can calculate your roof’s pitch by measuring from the edge of the roof over 12 inches to see the altitude over the roof line (the rise). You’ll need a slope multiplier to help with this calculation. Choose the slope multiplier that correlates with your pitch slope.
| 2 in 12 | 1.102 |
| 3 in 12 | 1.134 |
| 4 in 12 | 1.159 |
| 5 in 12 | 1.191 |
| 6 in 12 | 1.230 |
| 7 in 12 | 1.274 |
| 8 in 12 | 1.322 |
| 9 in 12 | 1.375 |
| 10 in 12 | 1.432 |
| 11 in 12 | 1.493 |
| 12 in 12 | 1.554 |
2 – Outline Your Roof on Paper
One of the easiest ways to visualize your roof from above is to Google it. Most people can get fantastic aerial views of their roofs from Google maps, and these views will help you to create your own outline on graph paper.
Label each section of your roof so you can easily tell which part you’re looking at. Later on you’ll make separate calculations for each section of the roof.
3 – Add Measurements to Your Outline
Start from the lower left corner and take measurements all the way around from eave to eave. When you get back to your starting point, your figure should line up neatly. If it doesn’t, you probably made an error somewhere along the way, so you should take your measurements once again.
4 – Section Off Your Outline
Find the area of each section by multiplying length times width. You should also include any triangular sections. Remember that triangles are easy to calculate: they’re merely half the length times the width. Mark each area calculation on your diagram.
6 – Total Your Calculations
Add up the total square feet by calculating the sum of each of the roof sections. With this figure, you’ll be able to determine your required quantity of roofing materials.
Without ever climbing up that ladder, you now have a diagram of your roof accurate calculations. You can use this diagram for getting estimates on materials and even for ordering.
For more information about safely measuring your roof from the ground, or to get a roofing estimate from a New York commercial roofer, get in touch with us at Z Abedin Construction LLC. As a New York roofing contractor, we can help with fixing roof leaks, inspecting your roof for problems, replacing your entire roof, or even installing siding and windows. We’re ready and able to help you with your next project!
