#METAL ROOF RAFTER SPACING INSTALL#

We can merge these two equations to get a single rafter length formula based on the roof pitch: So what you need to do first is to get the pitch, using the following formula: The one difference is that we need to calculate the roof rise using the pitch first. The formula used to calculate rafter length from roof pitch is, in fact, the same as the one above. What is more, the formula used to calculate roof truss dimensions is one you probably know very well - it's the exact same formula you use to describe a right triangle - Pythagoras!įor calculations based on the roof pitch: Usually, that is either the pitch or the rise of the roof. It all comes down to what information you already have. The rafter length calculator lets you calculate truss dimensions using two slightly different sets of variables. As soon as you fill in all the variables, you will see the total expenses at the bottom of the calculator.ĭon't worry if you're unsure what the roof's run, rise, on-center spacing, and such exactly mean - we've prepared an illustration of the variables you need to fill out in the calculator.

#METAL ROOF RAFTER SPACING INSTALL#

If you pick Yes, you will also need to declare how much per time unit the contractor would charge you to install the trusses, as well as the expected duration of the installation. The rafter length calculator will return the total expenses in the bottom-most field.

If you pick No, the only thing left to input is the cost of a single roof truss. In the appropriate fields of the calculator, decide whether you want to include the cost of installation in the calculations. Our tool can also figure out the approximate roof truss cost. Input the roof length, the on-center spacing (the distance between the middles of two neighboring roof trusses) and the rafter calculator will return the number of roof trusses needed. You can input roof pitch in whichever format you prefer (angle, percentage, ratio), and our tool will automatically tell you the other ones. You can input any of the two values to get the third one calculated. Here as well, our calculator works both ways. After doing that, you will see the rafter length in the bottom-most field. If you decided to include roof pitch in your calculations, you will need to input the run and the pitch of the roof to get the rafter length.

Metal roof rafter spacing