OPEN RAFTER TAIL DESIGN FULL
OPEN RAFTER TAIL DESIGN PRO

So I enter the number 6 into the calculator, followed by the Inch key, and then press the Pitch key.

I need one more element, and in this case I know the pitch of the roof, which is 6/12. Next, I press the Run key, instructing the calculator to use that dimension as the ‘run,’ which is the first element of the right triangle I am working with. The result on my Construction Master calculator is 2 ft. Then, I divide that by 2 to get the actual run of each rafter. I write this down on my template rafter as the adjusted overall run.

OPEN RAFTER TAIL DESIGN FULL

For simplicity, and to prevent error, the first thing I do is deduct the full width of the ridge beam from the building width: in this example 6 ft. 3/4 in., including the sheathing.Įach rafter only spans half the width of the building, and they start at the face of the ridge beam. The building width, in this example, is 6 ft. Looking at our model roof, I need to find the two elements that will give me all the information needed to frame the roof. Most of the time, the two values I have are the run of a building and a specified pitch, which is why I used these values for the example in this online tutorial: If you have any two of those values, the calculator will quickly figure out the rest of the right triangle-which means it will tell you everything else you need to know about a rafter. The values on the calculator that we use for common roof framing are: Pitch, Rise, Run, and Diagonal. They essentially do the same thing as an actual construction calculator, but I prefer the real thing-if I’m going to drop a calculator in the mud, I’d rather it not be my pricey smartphone! Using a Construction Calculator

There are also two laudable software versions available as smartphone apps: one from Calculated Industries, and one from BuildCalc. They put all the information in a nice, clean, easy-to-understand interface. These calculators eliminate some of the memorization, and all of the charts.

OPEN RAFTER TAIL DESIGN PRO

Side-by-side: The Construction Master Pro (left) and the BuildCalc app on an iPhone (right) (Note: Click any image to enlarge)Ĭonstruction calculators are pre-programmed with Pythagorean formulas for finding the values of right triangles-and roofs are all about right triangles.

Open rafter tail design