WhatsNew2Day
Latest News And Breaking Headlines

How to Measure Roof Frames for Beginners

So you want to frame the roof on your building? Knowing where to start, especially with the measurement, is essential.

Additionally, it’s essential for homeowners to learn the various measurements you will have to determine, such as the pitch and run of your roof. You can learn more about the basics of roofing from experts at Roof Master if you don’t already know how to measure these components of your roof.

The frame, especially the rafters, provide structural supports for the roof, so you must get your measurements correct in this part. Read the detailed outline below on how to measure roof frames for beginners.

This article will guide you in getting the accurate size for a gable roof frame.

Calculate the Length of the Rafters

When calculating the length of the roof rafters in your home, the first thing you will need to do is measure the width of your building. It’ll help you know how long the rafters need to be and the cutting angles from top to bottom. Ensure you use a well-calibrated tape measure to get precise measurements.

Get detailed measurements and round off to the nearest tens if you have to. A measure with a fraction such as ¼ inch or 1/8  inch could become 72.75 inches. Use a pencil to mark and measure every part 2 to 3 times to ensure accuracy throughout the project.

Measure the Width of the Beams

Next, measure the width of the beams and subtract your findings from the width of the building. A 2×4 beam is 1.5 inches. The new width, therefore, becomes 71.25 inches (180 cm). Ensure that you record these new measurements before proceeding with the next step in the project.

Divide the New Measurements by Two

Every rafter is typically half the building’s width, so you will have to divide the new measurement half. So 71.25 inches (180cm) becomes 36.63 inches (90.0 cm).

This halved measurement is the run, and you will jot it down with that title. A roofing calculator can store the run in its internal memory.

Calculate the Pitch of the Roof

Your next plan is to calculate the pitch of the roof. Typically it’s the number of inches that a roof rises vertically per foot of roof. It’s a ratio. You are simply getting the steepness of the roof.

Get the height of the roof above the top wall, then get the half-length of the room from one side of the ridge beam going to the edge of your building. For a roof that rises 7 inches (18cm) every 1 foot, then the pitch is 7/12.

Find the Length of Every Rafter

Next, get the length of each rafter using run and pitch. Your roof calculator can do that if you press the “diagonal” key. If you don’t have a calculator at your disposal, it will help to have trigonometry skills to calculate the length of every beam.

Another handy item you must have as you undertake roof framing is a manual that has rafter-length tables. You can measure your beams to hang past the edge of the building wall. All you have to do is add in the extra measurements separately.

Calculate the Rise of the Roof

Finally, you can calculate the rise of your roof. You measure it vertically to find out the height of the roof at its highest point. Typically, the rise is the exact height of the ridge beam. Your roof calculator has a “rise” button to help you with these calculations.

Otherwise, all you have to do is subtract the height of the walls from the total height of the roof’s peak. Ensure that you write down the rise and label it accordingly as well.

Outline the Cuts

The first cut you need to outline is the plumb cut, which is where the rafter meets the ridge board. It would be best if you had a pencil and framing square to outline the edge of the pitch.

Start by placing the long arm of the framing square on top of the rafter arm while the short arm sits upright. Your framing square should look like an elongated uppercase letter “L”.

Proceed to push the blade until it reaches the 7-inch mark on the short arm and 12-inch on the blade on the upper edge of the rafter.

Proceed to draw a line along the edge. The line will guide you through drawing down the rafter to get the line length. After achieving the desired rafter length, angle the framing square to start marking the bird’s mouth.

Hold the framing square perpendicular to the bird’s mouth line after turning it over. Ensure that the bottom measurements match the wall plate width and draw to the heel cut line. The heel cut marks the seat cut of the bird’s mouth. Going beyond the bird’s mouth is the rafter tail.

Once you have all the measurements that you need for the project, proceed to the cutting phase using a saw to get the first rafter. Cutting is easy since you can trace the cuts to the original rafter. Keep checking every pair of rafters you cut to ensure the rise, run, and other components are correct.

Alternatively, you can try to fix every rafter you cut to the bundling to see how they sit on the wall plates and the ridge board. It will allow you to make corrections on time.

Final Words About Measuring Roof Frames for Residential Buildings

Measuring and cutting the roof frame is not complicated once you break down the steps. Measuring and cutting the pieces for the frame of your roof is just the beginning. There are essential considerations to make when roofing, such as building codes.

If you find that you can’t hack the measuring process for a roof frame, you have the alternative to get ready-made trusses. After measuring a gable roof frame, it’s easy to master a rhythm of skill to ensure you can work on other more complex roofs.

This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More