Measuring Roof Rafters

Divide the adjusted width.

Measuring roof rafters.

Measure the width of your building. The slope you choose will mostly be a matter of preference. Use a tape measure or laser measuring tool to find the dimensions of. Determine the camber along the timbers length.

The first number represent the amount in feet that a rafter rises. As a general rule roofs that have a high human occupancy rate should be framed with rafters every 16 structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. Here the number is 941 86 inches. In our example we have a 7 12 roof 7 inches of rise for every foot of run.

Roof pitch is designated by a set of numbers such as 4 12 or 6 12. Print full scale rafter cut templates and birdsmouth templates fold template over rafter to mark or cut through. Calculate the span of. Calculate the length of common rafters with this free and easy online tool by entering a dimension for the roof width selecting a pitch for the roof and the thickness of the ridge.

Half building width minus 1 2 ridge thickness. Before you can mark the rafter lengths and layout check the. Rafter run outer wall this should be measured starting from the center of the roof span and then extending to the very edge of the exterior wall. Calculating rafter length 1.

Measure the length and width of the building. See rafter run to outer wall calculator below. From here mark a line every 16 across the front lentil. On construction calculators slope is often called pitch.

Measure the rafters begin by measuring across the front lentil and finding the center. Mark the plumb cuts. On a full gable roof this is equal to half the building width minus half the ridge thickness. The results are automatically fired.

Before you start cutting you first need to determine how long your roof rafters. Rafter run is the horizontal distance the rafter travels. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. Here the number is 1166 66 inches.

Subtract the width of your ridge beam. Allow for ridge thickness when determining rafter run to outer wall. Marking out the roof rafter lengths onto the timber before cutting step 1. The second number is the benchmark for typical pitched roof calculations.

Roof rise this should be calculated from the base of the roof to the highest point of the roof gable the peak. Determine the pitch of the roof which is the angle that rafters rise from the outside walls to the ridge. Make a mark 3 4 to the side to give a guide for the edge of the 2 x 8. Planning the dimensions of a new roof 1.