How to Calculate a Pitched Roof

A "pitch roof" isn't actually what everyone is asking for, from my understanding. It's not exactly a type. It's more of a measurement and angle. The roof pitch slope can tell you how many inches your roof rises for every 12 inches that it runs. You can also calculate rafters, from the bottom of the rafters. It's done pretty much the same way. It's more accurate because you don't have to involve any layers of roofing when calculating/measuring.

Difficulty: Moderate

Instructions

Things You'll Need:

• level
• pencil or permanent marker
• your roof
• a decent, less skin scorching day

1. So, one way to measure it is to mark a level at 12" from the top of the roof. Make sure to hold it completely level and measure it from the roof top surface to your 12" mark. This is the rise. It may not be completely accurate because of all the layers your roof may have.

2. To calculate your rafters is the same, but more accurate because you don't have the layers of roofing to worry about.

3. You can take your measurments from underneath a barge rafter on a gable end, underneath a rafter on an overhang at the bottom of your roof, and underneath a rafter in your attic.

Tips & Warnings

• 9/12 pitch means that the roof is raised 9" for every 12" that it runs. (Example)
• Calculation isn't as accurate when calculating roof pitch, however, it's closer when calculating from the bottom of your rafters.
• Be careful when on top of your roof...I believe we can all figure out why.

[Viol]

on 2/11/2009 helpful advice,, thanks

[tikrit01]

on 1/10/2009 This sounds tricky but like good advice. Thanks! 5 stars

[kqmsradioman]

on 11/11/2008 How bout slapping a torpedo level up against the barge, marking plumb,and checking pitch with a speed square? Common line, naturally.