How To Measure A Roof
This article was co-authored by David Bitan. David Bitan is a roofing professional, licensed contractor, and the owner and founder of Bumble Roofing based in Southern California. With over 12 years of construction industry experience, David specializes in restoring, repairing, and maintaining residential, commercial, and industrial roofs. With over 60 years of combined experience, Bumble Roofing provides easy, friendly services to structures including residential, commercial, industrial, multi-family, and government buildings along with hospitals, hotels, and churches.There are 13 references cited in this article, which can be found at the bottom of the page. This article has been viewed 356,161 times.
Measuring your roof is the first step in a successful re-roofing project. You can actually get an estimate of your roof’s measurements from the ground if you’d rather not climb a ladder and get up on the roof yourself. Otherwise, you can climb up onto your roof to take more accurate measurements. Either way, we’ve got you covered! This article will walk you through each process step-by-step.
What Else Impacts The Cost Of Your New Roof
Now you know how to roughly calculate your roofs square footage and 3 more factors that impact the cost. Remember, the only way to get a 100 percent accurate measurement is to have a local roofing contractor come out to professionally measure your roof.
Knowing your square footage and the 3 other cost factors lays the groundwork for learning the size of your roof investment. However, there are even more factors that impact the cost of your new roof besides whats listed in this article.
To understand where your hard-earned money is going when you invest in a new roof, we broke down the 9 factors that affect the cost of your new roof.
The team at Bill Ragan Roofing has provided high-quality roofing services in the Nashville area since 1990. We give you an experience rare in the roofing industry with our workmanship and customer service.Thats why were proud to offer you a lifetime warranty.
To learn what affects the cost of your replacement, check out 9 Factors That Impact the Cost of Your New Roof.
Roofing Quote Footage Is Not The Same As Home Square Footage
Depending on where the information is coming from is going to determine the basis on which the estimated roof footage is calculated. The roof square footage is what we need to calculate a budget quote to do the job. So when you say my home is 1,500 square feet, how much to do the roof? Well, that is a good question. Does that amount include the garage? Does it include the back covered lanai area that is encompassed in the main portion of the roof? Does it include the addition that was built last year? Does it include the 2 4 overhang or soffit area? Does it include the front entry? All these things could add much square footage to that 1,500 sq. ft. number. It also does not encompass all that is needed to come up with the square footage of the actual roof. This does not automatically mean the roof is 15 squares, as some might lead you to believe.
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How Do I Calculate How Many Shingles I Need
To estimate how many shingles youll need, you need to know the total square footage of your roofs surface. Find this number by measuring the length and width of each plane on the roof then multiplying length times width.
Calculating the number of bundles, you need is simple if you are using shingles that come three bundles to a square. Each bundle covers 33.3 sq. ft. of roof areawhich is close enough to the 32 sq.
Thereof, How many bundles of shingles do I need for 100 square feet?
three bundles
Also to know is, How many square feet are in a bundle of shingles? 33.3 sq. ft.
Subsequently, question is, How many shingles do I need for a 24Ã24 garage? Additionally, how many shingles do I need for a 24Ã24 garage? Three bundles are equal to one square. Each square equates to 100 square feet. In the previous example, three squares, or 300 square feet, of shingles will be needed to cover the garage roof.
Also, How many bundles of shingles do I need for 200 square feet?
How Many Bundles of Shingles Will You Need. The average bundle of shingles covers 33.3 ft2, so three bundles of shingles are needed per square.
Calculate The Square Footage Of Your Roof
Now that you thought about the slope and complexity of your roof, youre ready to learn how to calculate the square footage of your roof.
To get a rough estimate for your roofs square footage, youll use this equation:
For example, if you have an easy up and over, walkable gable roof and a house that measures 56 feet lengthwise and 28 feet widthwise, your calculation will look like this:
1,568′ =
x 1.3
2,038 = square feet of roof area
Using this equation wont be 100% accurate, but knowing your roofs square footage is a great jumping-off point to learn how much youll have to invest in your replacement.
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Recommendation Of How To Calculate Square Footage Of A Roof
The construction process likes precision. To correctly build and lay a roof firstly it is necessary to understand all nuances of how to calculate square footage of a roof.
Very often people decide to make a roof and a house itself on their own. In this case they should definitely know how to calculate square footage of a roof. In the space calculation you must be especially careful, since with the wrong approach you risk not only to get an ugly structure appearance, but also spend money for the purchase of excess materials.
Finding The Size Of The Roof In Squares
Roofing contractors estimate projects and materials by the square, so it is crucial to find this measurement to estimate the amount of material needed accurately. A square simply refers to a 10 x 10 square of roofing. This is simply 100 square feet of roof.
To find the squares, divide the overall roof area by 100 and then round up. For instance, if the roof is 1550 square feet, then it is 16 squares.
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How Do I Measure A Steep Roof
Most roofers wont go on a roof with an 8/12 roof pitch or greater with special equipment such as scaffolding and roof jacks and neither should you. Instead, use one of the four methods described above that allow you to measure the roof while standing safely on the ground or from the comfort of your computer.
While these methods may not be quite as accurate as taking actual measurements from the rooftop, theyre close enough for calculating how many shingles youll need to purchase for a new roof.
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Monopitch Roof Design Calculations
The design feature of this structure is that it has a rectangular shape, so there some problems with performing computations.
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How Many Bundles Of Shingles Per Square
A package of roofing shingles is called a bundle. Laminate or architectural shingles, one of the most common types of roofing shingles, are generally packaged in three bundles per square.
So in the 2400 square foot gable roof example, you would need 72 bundles of shingles .
Here are a couple more examples:
The Operating Cost Of Your Roofing Contractor
Every roofing contractor has operating expenses to keep their business going. These operating costs will always factor into the price of any roof work that needs to be done.
Some common operating costs are:
- Building cost and utilities, shop and truck yard
- Advertising and promotions
- Payroll and payroll taxes
- Taxes
These are just some of the fixed operating costs that it takes to run a business. No matter if a roofing company does a simple repair or replaces 10 roofs, these are the costs that have to be paid every day. No matter what work you get done or what service you need, operating expenses will always factor into an estimate or final cost.
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Calculate The Exact Roof Area
Follow these steps to figure out the exact area of your roof:
- Take your pitch number and divide it by 12. For example, if your pitch is 4 in 12, you need to divide 4 by 12. The answer will be 1/3.
- Next, you need to square your outcome. In our example, 1/3 squared will yield 1/9.
- Thereafter, add 1 to your result: 1/9+1=10/9
- Calculate the square root of your new number: The square root of 10/9 is 1.05.
- Measure the length of your house including the overhangs.
- Measure the width of your house including the overhangs.
- Multiply the length of your house by its width to get the area. For example, 40 feet x 20 feet = 1,200 square feet.
- Thereafter, multiply the area by the pitch to get the true roof area: 1,200 x 1.05 = 1,260 square feet.
In order to allow for ridges, hips, and waste, it is advisable to add 10% of your final roof area for a gable roof or 17% in the case of a cottage roof.
As a result, you should be working with 1,386 sq. feet or 1,474 sq. feet for a gable roof or a cottage roof respectively. Get to know more about us!
Know Your Roof Type
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How To Measure Your Roofs Square Footage
The square footage of your roof has a huge impact on the cost of your replacement. It affects a number of cost factors, including the amount of materials used, labor, and time.
Be aware, the only way to get a 100 percent accurate measurement is to have a local roofing contractor come out to professionally measure your roof and give you a quote. However, I can give you the calculations to get a rough measurement of your homes square footage.
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Draw Each Shape Individually Calculate Each Area And The Total Square Footage Of Your Roof
Now we have eight shapes to find the area of six triangles and two rectangles. Instead of breaking out the old textbooks to calculate triangle areas, we like to use a triangle calculator. It makes figuring out the area of triangles a lot simpler.
In the example above, we have two triangles with sides of 30, 20, and 20 feet. Pop those figures in the three-sides calculator and youll get an area of 198. Since we have two of those triangles, multiply by 2 for a running total of 396 square feet.
We have four remaining triangles, all with dimensions of 15, 20, and 25 feet. That same calculator reveals a result of 150 square feet. Since there are four of those triangles, multiply by 4 to get 600 square feet.
Lastly, we have two rectangles of 15 by 30 feet. This one is easy, just width times height for a total of 450 square feet for each one. Multiply by 2 and their total square footage is 900.
Adding all the areas up yields a total of 1896 square feet . Since roofing material comes in 100 square foot squares, youll need at least 19 of them for your roofing project. Itd be wise to get at least 20 to account for mistakes and waste.
S To Calculate Your Roofs Square Footage
You just learned what a roofing square is. The number of roof squares has a huge impact on the cost factors, such as the amount of materials used, labor, and time.
Before investing in a new roof, wouldnt it be great to know how much itll cost per square?
If you answered yes, we have a great way to roughly calculate your roofs square footage to give you an idea of the cost of your new roof. Be aware, the only way to get a 100 percent accurate measurement is to have a local roofing contractor come out to professionally measure your roof.
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How Roof Pitch Is Calculated
To accurately calculate the area of your roof, you must first determine its slope, or pitch. A roofs pitch is determined by how much it rises vertically for every foot it runs horizontally. Thus, a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. A 12 in 12 pitch is a steep, 45-degree angle roof. See the image below for more explanation on rise, run and pitch.
One: Get Up On Our Roof Safely And Take Initial Measurements
Sketch out the shape of your roof on graph paper. In this example, youd only need to measure the overall width and length, the central ridge, and one of the hips . If you have a more complex roof shape with dormers, take all the measurements you can and prepare to use your eraser to refine the image of your overall roof structure. Make sure you have solid footing and if possible, use fall protection to keep yourself safe. Be mindful of hazards like ridge vents. Note the lengths in feet:
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What Is A Roofing Square A Comprehensive Guide
By: Author Ryan M.
A roofing square is the most common unit of measurement for materials that are used to cover roofs. Theres a tool used for convenience but theres also a quick way to determine the answer:
What is a roofing square? A roofing square, often known as a square of roofing shingles, is the quantity of material required to cover 100 square feet of roof area. Contractors, manufacturers, and suppliers use the phrase as a shorthand to define the size of a roof. A 2,000 square foot roof, for example, is 20 square.
A Roofing Calculator For Quick And Easy Measurements
First you have to measure each side of your house from the ground using a measuring tape. If you multiply the length by the width youll know the ground area of your house. Many times a house does not have a square or rectangular shape. If your house has an irregular shape, you have to divide the ground area in separate parts and figure their area. To know the total area of the house, simply add them together.
The second step is to convert the area of the house in roofing squares. Each 100 square feet of roof is one roof square. So you have to divide house area by 100. If your house area is 2000 square feet, the number of roofing square for the roof will be 20. In metric system, the house area will be approximately 186 square meters, because 1 meter is equal to 10.76 feet. The number of roofing squares for 186 sq. meters is also 20.
The next step is calculation of the roof pitch. Roofs have one of three pitches: low, medium or high. A low pitch rises 3 inches every 12 inches of base horizontal length. A medium pitch rises 6 to 9 inches every 12 inches of base horizontal length. A high pitch roof rises more than 9 inches for every 12 inches of base horizontal length. You can estimate the roof pitch by sight.
Roof pitch
Finally, to get the square roof area multiply the number of roofing squares for a low-pitch roof by 1.06 to 1.42 depinding of the roofs pitch. to get the square roof area.
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How To Estimate The Size Of A Roof
If youre replacing a roof, the first consideration needs to be the roofs size so you can accurately estimate project materials.
In the U.S., roofs are measured in square footage, and roofing contractors typically quote projects based on the size of the roof in squares. Consequently, gathering the size of the roof in squares and square footage is the first step.
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What Influences A Roofing Projects Cost
Although a roofs size is always a major factor in calculating project costs, other elements may influence a contractors quote, such as:
- Your location and the average roofing project prices in your area.
- Your choice of roofing material
- Roof accessibility and ease of installation
- The contractors certifications and level of work
- Project timeline
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Square Footage Information Changes Depending On The Source
The real estate listing has a home square footage number, but no basis on what this represents. The property appraiser has a square footage number, but they are only looking at your property tax liability. You have a number in your mind from when you bought the home, or a round-a-bout number that you may have used in other projects, but is this number even accurate? The numbers you have may only be air conditioned space, because isnt that what is most important?
Calculate Roof Pitch From The Ground In Three Quick Steps
Roof pitch is one of those things that middle school math and geometry instructors can easily point to, and say, See? Learning how to work with rise over run is fun and useful, right? If at any moment you start having PTSD flashbacks to algebra or geometry class, take a deep breath. Well walk you through this slowly in three simple steps. All you need is a tape measure, and possibly a helper to hold it.
Step One: Grab that tape measure, notepad, and pencil and head outside. Find the slope of your roof youd like to measure, and start measuring the distance from the outer edge of the eave to the point at which the plane of the roof slope is barely visible to your eye. Write that number down in both inches. This figure is the horizontal run.
Step Two: Stand directly underneath the gutter or edge of the roof plane you want to calculate the slope for. Measure the distance from your eye to the top of the drip edge of your roof overhang. Write that number down in inches, too. This figure is the roof rise.
Step Three: Take the roof rise figure in Step Two and divide it by the horizontal run from Step One. In the example above, the rise is 60 inches and the run is 120 inches. This reduces down to a roof pitch of 6/12. Well use this figure in just a bit, so keep it handy.
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