How To Figure Out Roof Valley Angle

The preview window displays a plan view of the valley roof.

How to figure out roof valley angle. The hip and valley factor varies according to the slope of the roof as shown in the table below. This slope and skew calculator makes it easy by performing all of the necessary trigonometry for each hanger condition in the roof. Here are the steps to follow for the roof angle calculator. If you use the wrong dimensions you will find the wrong angle.

To calculate what r and a are note that rcos q a r cosq cosa r sinq sina r cosa cosq r sina sinq by the above identity. So we have two equations. Find the square root of the result. The calculations will be.

First enter the value of the rise and choose the unit of measurement from the drop down menu. For any roof slope expressed as x in 12 rise in run the hip and valley factor is determined by finding the square root of rise run 2. Check all your measurements twice. Hopper valley angle calculation inputs internal angle wall a to vertical α1.

Divide the rise by the run the run is 12. To calculate a valley roof select valley from the roof type dropdown list or click on the the corresponding button on the toolbar to calculate a valley roof. Rcosa a 1 rsina b 2 we can find a by dividing 2 by 1. Simply enter the roof pitches and press the calculate button the calculator will supply the direction and precise angles for the framing members as well as the connectors.

So we need to set rcosa a and rsina b to make this equal to acosq bsinq. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length. Results internal valley angle to vertical α3 degrees external angle to horizontal α4 degrees. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement.

Degrees note type in respective value inside of coloured cell above then click outside cell to enter. Then enter the value of the run and choose the unit of measurement from the drop down menu.