Measuring Roof Rafters

The slope you choose will mostly be a matter of preference.

Measuring roof rafters.

Allow for ridge thickness when determining rafter run to outer wall. Divide the adjusted width. Determine the camber along the timbers length. See rafter run to outer wall calculator below.

Subtract the width of your ridge beam. Decide how steep a slope you want your roof to have. Measure the rafters begin by measuring across the front lentil and finding the center. 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.

Marking out the roof rafter lengths onto the timber before cutting step 1. Planning the dimensions of a new roof 1. The second number is the benchmark for typical pitched roof calculations. Mark the plumb cuts.

Rafter run is the horizontal distance the rafter travels. The first number represent the amount in feet that a rafter rises. Roof rise this should be calculated from the base of the roof to the highest point of the roof gable the peak. Measure the length and width of the building.

Roof pitch is designated by a set of numbers such as 4 12 or 6 12. The results are automatically fired. From here mark a line every 16 across the front lentil. Calculating rafter length 1.

Before you can mark the rafter lengths and layout check the. On a full gable roof this is equal to half the building width minus half the ridge thickness. 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. In our example we have a 7 12 roof 7 inches of rise for every foot of run.

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. Here the number is 1166 66 inches. With the tape measure hooked onto the top end transfer your two rafter lengths onto.

Half building width minus 1 2 ridge thickness. Print full scale rafter cut templates and birdsmouth templates fold template over rafter to mark or cut through. Make a mark 3 4 to the side to give a guide for the edge of the 2 x 8. On construction calculators slope is often called pitch.

Measure the width of your building. Calculate the span of. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. Use a tape measure or laser measuring tool to find the dimensions of.