What does Roof Pitch Mean?

One of the most commonly used terms in roofing. So what does it mean?
Roof pitch (or slope) tells you how many inches the roof rises for every 12 inches in depth.

An Example of a roof pitch would be a "6/12 pitch" which means that the roof rises 6 " for every 12" inward towards the peak (or ridge).

There are two suggested ways to measure a roof pitch.
The first is from the top of the roof. Simply mark a level at 12". Keeping the level balanced measure the distance from the level to the roof surface. If a roof has many layers of shingles your measurement could be slightly innaccurate using this method

The second is to measure from the bottom of the rafters. Measuring the pitch is still the process but you you can measure the roof pitch from three different locations using this preferred method. The underside of a rafter on an overhang at the bottom of the roof, the underside of a barge rafter on the gable end, and the underside of the rafter in the attic.

SmartVent is recommended for pitches that are 4/12 or higher. Now that you understand how to calculate your pitch, you will know if SmartVent attic Intake ventilation is right for your home or project. SmartVent is a patented roof and attic ventilation product that provides the best passive attic ventilation available. Using a unique design and installation method, SmartVent eliminates the problems and inefficiencies found in roof construction using ridge and soffit venting, namely inadequate vent openings in the soffit.