How To Find The Pitch Of A Roof With A Framing Square

In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches.

How to find the pitch of a roof with a framing square.

The most precise way to find the roof s slope is by measuring it from the underside. The swanson speed square is a popular tool with most carpenters. Locate the level s 12 inch mark. Finding the pitch of a roof is simple with a speed square.

This article explains how to make quick use of a framing square and its imprinted data to get some basic roof measurement data like roof pitch or slope rafter lengths and end cuts. So if the pitch of your roof is 7 12 place one stair gauge on the vertical part of the framing square the tongue at the 7 inches 18 cm mark and place one stair gauge on the horizontal part of the framing square the body at the 12 inches 30 cm mark. A carpenter s framing square includes some tables stamped right into the tool itself. On a ladder beside the roof place the level a foot or so up the roof hold it level and measure from the 12 inch mark on the level s bottom straight down to the roof.

Use a level against the underside of the rafter you re measuring to get the most accurate value. 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. Pitch of hips the pitch is based on a 12 run on the framing square. The triangle shaped square was invented in 1925 by albert swanson to provide a quick accurate method for marking rafters.

If this distance measures 4 inches you have a 4 in 12 pitch. 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. Pitch measurement method 1. For example a 12 12 roof pitch would have 11 1 16 12 pitch hips.

8 inches and you have an 8 in 12 pitch. Access one of the rafters then take the measurement this way. Fix stair gauges on the framing square to mark the pitch. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run.