Roof pitch is the name of the angle of a roof. If you’re thinking about a roofing project—such as skylights, an addition, or cutting in new rake boards—then it’s important to know what the number is. Builders may ask this to get started on a home remodel project.

How you calculate the roof pitch of your home is fairly simple, and it can be done from inside your attic or on top of your roof. You’ll need an 18- or 24-inch level, a tape measure, and a pencil.

In the attic, place the corner end of the level against the bottom of a roof rafter. Make sure it’s perfectly level
From that corner end, label the level at the 12-inch mark with a pencil.
3. Measure vertically from the 12-inch mark on the level straight up to the underside of the rafter just above it. Record that measurement.

Slope is the ratio of the vertical distance you recorded in step 3 with the horizontal distance you began with (12in). So, if there was a vertical distance between your level and the next rafter of 6in, your slope is 6:12, or “6 in 12”. And that’s it.

The primary reason that roof pitch exists in the first place is to redirect water and snow. If you live in an area known for heavy rain and snowfall, it might be best to consider a steeper slope to account for the cold weather.

As far as deciding on a roof design, there are a number of crucial, yet basic reasons why the pitch factors into your decision process. The following are just some examples:

The type of materials to be used (such as composition, shakes, or tile, for instance)
Walkability on the roof
Proportions to the building


Low slopes. They can be constructed easily at a more expensive cost, but then you can’t use asphalt shingles for low-pitched roof design. These types of roofs are expensive, demand high-end materials, and require a regular maintenance visit.

Conventional. These are still fairly easy to walk on, and is a good option for those looking to add a shed, a garage, or a general room area.

Steep slope. These pitch types deters more of the harshest climates, as the angle deters rain and snow from damaging your house. They are efficient and stable, lasting you years of quality roofs.

Determining your roof slope can change the look of your home dramatically, whether your project is big or small. It’s also important to know your roof slope, so you can get started nailing down the specifics of the project with your builder.

Any questions? Please let us know by contacting us, or commenting. We are experts in the home roofing business, and we hope that we can add our experience and expertise to your project.


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