How To Read A Speed Square For Roof Pitch

If you wish to double check the tool s accuracy or you don t have a pitch finder on hand you can also manually measure and calculate roof slope.

How to read a speed square for roof pitch.

Ask this old house general contractor tom silva demonstrates the amazing versatility of the humble rafter square. The pitch of the roof is read where the bottom of the rafter crosses this scale. Subscribe to this old house. Use a speed square and go inside the attic.

You can use the speed square to mark an angle such as when cutting a rafter tail by holding the pivot point against the board. Using the pivot point the notch on the non lip leg of the square adjust the square until the degree gradation you need lines up with the edge. Place the speed square on the plumb line and read the pitch on the square. Mark the location of the diagonal edge.

Mark a plumb line on one of the common rafters with a level and a pencil. Simply place the pivot point of the speed square against the roof shingles then use a torpedo level on the larger or fat side of the square. And it can be used to mark any angle between 0 and 90 degrees across a board s face. Once adjusted level the torpedo out until it can be read as level.

It can be used to make lines perpendicular square to a board s edge. Put the square against the surface of the material you want to use. The aim of this tutorial is to provide an understanding of how to read two main scales on a speed square. To find the pitch just place the pivot point against the shingles.

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. That will create a 45 line. Draw a pencil line along the square on the surface. Roof pitch the speed square can be used to find the pitch of a roof with a fairly painless and remarkably simple technique.

Note the number on the common scale parallel with the 45 degree angle of the square.