This is called the plumb line.
How to read a speed square for roof pitch.
It can be used to make lines perpendicular square to a board s edge.
A speed square will have two specialty protractor angle guides on the inside of the tool which has both common rafter angles.
To find the pitch just place the pivot point against the shingles.
Because of its compact size it is frequently used as a saw guide when cutting framing members as well as a layout tool for quick 45 and 90 degree cuts.
Find a common rafter angled with the pitch of the roof.
The aim of this tutorial is to provide an understanding of how to read two main scales on a speed square.
To calculate the required rafter length multiply the total run length half the building width plus the width that the roof is to overhang the house wall by this number 13 42.
Then place a torpedo level on the fat base of the rafter square and adjust the square until the level is level and read the pitch on the side of the rafter square.
Use a spirit level to mark a straight vertical line across the rafter.
How to use a rafter angle square for roof pitch.
And it can be used to mark any angle between 0 and 90 degrees across a board s face.
Directly below the 6 inch mark on the framing square read the required rafter length 13 42 per foot of run for a 6 inch rise 6 in 12 roof.
You can use the speed square to mark an angle such as when cutting a rafter tail by holding the pivot point.
Align the lip of the rafter angle square along the plumb line.
The triangle shaped square was invented in 1925 by albert swanson to provide a quick accurate method for marking rafters.
A speed square aka rafter square or triangle square is a measuring multitool.
A speed square is a tool that just about every carpenter will have in her bag.
I discuss a couple.
You can use a speed square to find pitches.
Made of steel aluminum or plastic this common carpenter s tool combines a ruler a try square a protractor a line scribing tool a common width board ripping guide and a saw guide for making accurate 90 and 45 cuts with a hand or circular saw.
Http bit ly 2cfqrn1 more project and tips.
Finding the pitch of a roof is simple with a speed square.