Roof pitch is the measure of a roof’s steepness and is a critical factor for roofing contractors in choosing the roofing material to be used. Sentry Exteriors takes an in-depth look at how roof pitch affects this choice.
The Basics of Roof Pitch
Roof pitch is typically represented as a fraction. The first number, (the numerator in a fraction) is the vertical rise. The second number, the denominator, is the horizontal run and is always 12 inches. Therefore, the roof pitch is read as the inches of rise per foot of run. For example, a 9/12 pitch means that the roof should rise nine inches for every 12 inches. Roof pitch is also represented as a ratio and is read the same way as a fraction.
Roof pitch applies to all kinds of roofing. Even the so-called flat roof actually has a slight pitch, from 0.5/12 to as much as 2/12, which is important in ensuring effective drainage and avoiding problems such as standing water. Gutter companies also factor in pitch when choosing gutter types. Low-sloped home styles such as Ranch homes typically have 2/12 to 4/12 slope, while most residential styles have up to 9/12 pitch. Anything higher than 9/12 is considered a steep-pitched roof.
Choosing the Roofing Material
A new roof installation that includes rebuilding the structure allows better flexibility on balancing the roof pitch and the choice of roofing material. On the other hand, a re-roofing project means the roof pitch will stay the same as the original, since the roof will be stripped down to the deck material.
Fortunately, most residential roofing materials work with pitched roofs. Asphalt shingles, including traditional three-tab and “dimensional” shingles are ideal, as well as sheet metal roofing. Heavy materials like slate and tile work in pitches up to 9/12. Installing them on steeper roofs can compromise their performance. It’s important to remember that steep-pitched roofs have bigger roof areas, therefore they will cost more.
To learn more about our roofing services or our other products including gutter guards, call Sentry Exteriors today at (434) 333-7753. You can also fill out our contact form to schedule a free estimate. We serve Roanoke, VA and surrounding areas.