#SHED ROOF RAFTER CALCULATOR INSTALL#

If you have a simple gable shed roof, then using 2×4 rafters makes more sense unless you have a very large shed. For roofs that will experience heavy snow or wind and will span the same distance, use 2×6 rafters. For roofs that won’t experience heavy snow loads, a gable roof can span up to 22’ with 2×4 rafters. You can use either 2×6 or 2×4 rafters for roofs with a 3/12 pitch or greater, but it depends on the overall size of your shed. However, one of the main issues you will encounter when cutting rafters is, should you use 2×4 or 2×6 rafters for your shed roof? They require less lumber than trusses and once one is cut, all the others follow the same cut. If you're unsure about the terms such as the on-center spacing, refer to the illustrations below: (Image created on the basis of: King post truss 3D created by George Ponderevo, licensed under the Creative Commons Attribution-Share Alike 3.0 Unported licence.Rafters are a simple, straightforward way to frame the roof of your shed. If you're interested in more details about calculating roof truss count, visit our roof truss calculator. Total costs = truss count * single truss price Total costs = truss count * single truss price + cost per time unit of work × duration of work To calculate the costs, we use the following two formulas: Rounded up to the closest integer (for example if the result is 14.5, you need to get 15 trusses). To do so, it uses the following equations: If you're unsure about the terms such as roof run and rise, refer to the illustration below: (Image created on the basis of: King post truss 3D created by George Ponderevo, licensed under the Creative Commons Attribution-Share Alike 3.0 Unported licence.)Īs you know, figuring out rafter length and other truss dimensions is not the only thing you can use this tool for! Our tool calculator can also help out with planning out your roof project by estimating the truss count and showing you the costs you can expect for the materials and their installation. 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.

#SHED ROOF RAFTER CALCULATOR 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.

Shed roof rafter calculator