by Jami Wright

Created on: April 29, 2009

Measuring roof pitch is like stepping back in time to your high school algebra class. I remember being told that I would need this in my daily activities but I don't remember what it was. I guess my high school math teacher was right (thank you Mr. Burg). Lesson learned.

I don't know about you but I really had a hard time with these types of equations. Math is not my speciality and while there are some interesting mathematical equations you can use to determine the pitch of your roof, I wouldn't be able to explain them, much less write them out. So let's break it down so even I can understand how to measure the pitch of your roof.

If you think of this as an adventure this should be fun. First, grab a ladder a framing square and maybe your spouse to help you with moral support. Just kidding this is fairly easy but please remember to follow ladder safety.

Next, go to the side of the house and place the ladder so that you have access to the roof, it should slope from left to right or right to left, not away from you.

Place the framing square against the roof, long end towards the center and short end points towards the ground. You should now have a right triangle with the roof's edge as your third line. Now move the long end of the framing square to where it meets the edge of the roof at the 12" mark. (You use twelve because that is how many inches are in a foot.)

Level the square both vertically and horizontally. The measurement on the short end is your rise. So you measured your roof and the result is 4/12. What does that mean?

In relation to roof pitch (rise/run) it means the roof rises 4" for every 12" it runs. Rise is the vertical incline and run is the horizontal slope. Easy right? On paper, maybe.

So what can you do with this information? Here are some of the reasons why you want to know your roof pitch: if you are calling around to price replacing a roof one of the first questions they will ask is what is the roof pitch. When wanting to add an addition like a sky light to your roof you will need to have that roof pitch number, and any kind of roofing products you might be looking to buy may require that wonderful roof pitch number. I can relate because when I go clothes shopping for my husband I need to have his sizes ready too.

One added thought, not all roofs have one pitch, you may need to measure more than once. So I did the best I could to explain how to measure a roof pitch and I hope this helps.

Learn more about this author, Jami Wright.
Click here to send this author comments or questions.