How we calculate the square feet of your roof

The fundamental factor that affects a roofing project's cost is how to calculate the square feet of the roof, upon which most other costs depend.

Residential and Commercial Roofing Projects
Blackhawk Roofing
September 7, 2024
by Dan Schnell

Introduction

When it comes to roofing, whether you’re considering a complete tear-off, a simple repair, or routine maintenance, one of the most crucial elements in determining the overall cost is the square footage of your roof. Accurate square footage calculations not only influence the price of materials and labor but also play a vital role in the longevity and performance of your roof system.

A fundamental factor affecting a roofing project's cost is the roof's square footage. It is the foundation upon which all other cost components, including materials, labor, and additional features, are calculated. Let’s explore why accurately measuring your roof's square footage is essential, the methodologies for doing so, and how it ultimately impacts the overall pricing of your roofing project.

The importance of accurate measurements

Accurate measurements are crucial in roofing as they directly influence the cost, materials needed, and overall project timeline. Whether it's a residential tear-off or a simple repair, having the correct square footage ensures that we allocate the right resources, reducing waste and saving you money in the long run.

Step-by-step calculation process

• Measuring the footprint of your home. The first step in calculating your roof's square footage is to measure the footprint of your home. This involves determining the length and width of your house. For a straightforward rectangular or square home, this is simply the length multiplied by the width. For instance, if your home measures 50 feet long and 30 feet wide, the footprint is 1,500 square feet.

• Understanding roof pitch. Roof pitch refers to the steepness of your roof, which significantly impacts the total square footage. Roofs are typically measured in terms of "rise over run," which indicates how many inches the roof rises for every 12 inches it runs horizontally. For example, a 5/12 pitch means that for every 12 inches of horizontal distance, the roof rises 5 inches. To convert a pitched roof's measurement into square footage, we use the pitch factor derived from the Pythagorean theorem, resulting in a more accurate representation of the sloped area.

• Calculating the total roof area. We calculate the total roof area once we have determined the footprint and pitch. For a gable roof with two sloping sides, we multiply the footprint by the pitch factor to account for both sides. Since the pitch factor is 1.3 for a 5/12 pitch, our earlier example would use a roof footprint of 1,500 square feet x 1.3 = 1,950 square feet. Here are the standard pitch factors for determining the required square feet of roofing material:

  • up to 5/12 pitch (1.3)
  • 6/12 to 8/12 pitch (1.4)
  • Complex/steep roof (1.6)

• Accounting for additional features. Most roofs have extra features that can affect the total square footage, such as chimneys, skylights, and dormers. Each feature must be measured separately to determine how they impact the overall area. For example, if a chimney occupies a 3-foot by 3-foot area, we subtract that from the total square footage.

• Final adjustments. Finally, we will make adjustments for waste due to cuts and overlaps, which typically add 10-15% to the total material needs. This ensures that we have enough material to complete the job without delays.

Tools we use

At Blackhawk Roofing, we employ a variety of tools to ensure accurate measurements, including:

• Measuring tapes and laser measurers. For precise distance measurements.

• Digital measuring software. This allows us to utilize satellite imagery and advanced algorithms, providing a visual reference for roofs with complex shapes.

• Drones. For harder-to-reach areas, drones provide a bird’s-eye view, allowing us to gather data safely and accurately.

Summary

Calculating the square feet of your roof is a meticulous process that requires attention to detail and the right tools. At Blackhawk Roofing, we take pride in our systematic approach, which ensures that each calculation is accurate and tailored to your specific roof type and design.

By understanding your roof's footprint, pitch, and additional features, we can provide an accurate measurement that helps streamline the roofing process. This saves you time and money and guarantees that your new roof will be built with the utmost care, creating a watertight and worry-free system you can rely on for years.

Blackhawk Roofing has built replacement roofs for thousands of residential and commercial customers in Springfield and Central Illinois. We've also done hundreds of roof repairs. Blackhawk Roofing provides outstanding value on every project. Call owner Dan Schnell at 217-741-6251 to schedule a Free Estimate.

Licensed Roofing Contractor

Blackhawk Roofing is a licensed, certified, and insured roofing contractor. We specialize in residential roofing and EPDM commercial roofing. We have repaired or replaced thousands of old and damaged roofs in Springfield and Central Illinois.

Proud to be the best roofing contractor in Springfield