How To Measure The Rafters For Roof Framing

Measure the width of your building.

How to measure the rafters for roof framing. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length. Subtract the width of your ridge beam. Rafter is a sloping beam usually wood that supports a pitched roof. You can determine the length of a common rafter using either of two easy methods.

Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. Calculating rafter length 1. Take a direct measurement of the width of the roof. This must be from walls that are of equal heights.

Includes result for hip valley factor slope factor and the roof slope in degrees. Cut the rafters to find the location of the rear lentil for the rafters use a framing square. If they are not then click here for the unlevel wall rafter calculator. Once you located where the mark falls on the 2 x 10 measure the distance and be sure to add 10 for the overhang.

Divide the adjusted width. Remember if you are using the center of the ridge. Cut one end of each 2 x 8 rafter to get the necessary length desired. To determine the finished height of the ridge beam add the rise m and the y height.

Use our online rafter length calculator to quickly compute the length of the shed roof rafter by entering the measurements of overhead length of roof span pitch or angle. On a full gable roof this is equal to half the building width minus half the ridge thickness. In our example we have a 7 12 roof 7 inches of rise for every foot of run. Roof pitch calculator results explained.

The ridge beam is the vertical piece of plywood which will form the peak 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. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement. The top of the ridge beam m y.

Before you start cutting you first need to determine how long your roof rafters. Use the number boxes to enter the value in feet inches and fraction inches and fraction. Rafter run is the horizontal distance the rafter travels. To determine the y height measure from the bird s mouth up the calculated slope x in 12 to the top of the rafter.

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. A by measuring the actual distance from the outside of the wall s top plate same location as the rafter s bird s.