measuring roof slope

How to accurately measure the slope of your roof by hand

Published by Pawel Matonog

Slope is also sometimes referred to as “pitch”. The greater the slope, the more material will be required to complete the installation of the roof and the harder the installation of the shingles are. This is why the slope factor is such an important calculation in my initial inspection of a homeowner’s roof.

Archer Roofing provides free roof inspections in Toronto, where I will accurately measure the slope and square footage of materials necessary for the homeowner, as well as provide them with my honest insight about the state of their roof.

I usually do all of the inspecting and measuring, but I have met many homeowners who take an avid interest in the renovations of their home and want to determine the pitch of their own roof as well as the amount of roofing materials required. It is quite easy to do this process by oneself, but installing shingles is a whole other ballgame and I always urge homeowners to leave that to professional installers!

If you have a smartphone or tablet handy, Pitch Gauge is a handy app that allows you to calculate the pitch of a roof safely from the ground. You can then fairly accurately calculate the square footage of your roof using their built in calculator. The slope factor multiplied by the area of the roof will give you the number of square feet to be covered by new shingles.

If you don’t have access to Pitch Gauge, are not afraid of heights, and have the necessary ladder and tools, measuring the pitch of your own roof by hand is another option.

First, you must have a long enough ladder to reach the top of your roof. After securing the ladder safely, make your way up to the roof with a 12” level and a tape measurer.

measuring roof slope

A level and tape measurer are necessary tools for determining the slope of your roof by hand

Set one end of the 12” level on the roof surface – make it level. Take a tape measure from the other end down to the surface of the roof. This will give you the slope of the roof. For example, a roof rising 4-inches for each horizontal foot has a 4/12 slope. The slope factor multiplied by the area of the roof will give you the number of square feet to be covered by new shingles.

We would be happy to calculate the slope of your roof and discuss your roofing needs, call 416-427-2437 for a free inspection by Archer Roofing.