Knowing how shingles work and the minimum roof pitch is crucial. Hence, this article explores what is roof pitch and the minimum pitch for shingles, asphalt shingles, and metal roofs need.
Calculating the minimum pitch of the roof has several benefits. In addition to adhering to building codes, it ensures that the roofs provide adequate protection for the living or storage areas beneath them.
Minimum Pitch for Shingles Definition
First of all, pitch refers to the angle (inclination) of the roof. To calculate a ratio, divide the vertical distance by the horizontal for every 12 inches/feet of vertical rise. By measuring the roof rise over its run, we can determine its pitch. While the rise is variable, the run remains constant.
If the roof pitch is 5/12, then every 12 inches of length will result in a 5-inch height rise. When the slope is 8/12, the height rises 8 inches for every 12 inches of length.
When the rise is higher, the roof pitch is steeper. When a roof has a 3/12 pitch, it has very little pitch, but when it has a 12/12 roof pitch, it will have a very steep pitch.
Minimum Roof Pitch For Shingles
Ideally, the minimum roof pitch for shingles should be 2:12. A roof pitch of 2:12 will require underlayment around the eaves to install shingles.
However, the minimum pitch for metal roof installation varies according to what kind of material you use and how you install it.
For non-soldered panels and metal roof shingles, the minimum pitch is 3:12.
Read also: Can You Shingle Over Shingles to Cut the Renovation Budget?
What is Asphalt Shingle?
Asphalt shingles are the most common roofing material in North America. Roofs like this are resistant to extreme weather conditions and add significant value to your home.
In addition to their ability to resist severe weather conditions, asphalt shingles are also affordable, simple to install, and versatile.
Generally, Asphalt roofs come in many different designs and colors. There are a variety of roof designs for homes, including sloped or angled ones. Also, there are other two common types of asphalt shingle, such as:
1. Architectural Shingles
First of all, architectural shingles consist of an additional layer of asphalt laminated to each of their lower portions. Laminating the surface gives the product a contoured, three-dimensional appearance. Sealant-bonded asphalt strengthens waterproofing capabilities. Though durable, these shingles are not ideal for low-sloped roofs susceptible to wind-driven rain.
2. Three-Tab Shingles
The second type is Three-Tab Shingles. Those with tabs and cutouts on their long lower edge are the most affordable and popular option. They look like three separate parts after installation.
Read also: Are Architectural Shingles Worth Extra Cost?
Minimum Pitch for Asphalt Shingles
The International Building Code recommends using asphalt shingles only on roofs with slopes over 2:12.
In actuality, the minimum pitch recommended by some manufacturers is 2:12, not 4:12. It is impossible to cover a low slope or flat roof with asphalt shingles because water cannot sit or hold on them. As a result, asphalt shingles cannot be installed on roofs with pitches less than 2:12.
Taking the vertical rise of the roof and dividing it by the horizontal run, we can calculate the roof slope. If it has a 2:12 roof slope, it rises 2 inches for every 12 inches horizontally.
As a rule of thumb, three-tab asphalt shingles perform best on roofs with a 4:12 pitch or higher, but you may be able to get away with a 2:12 with additional protection.
It is strongly recommended that you hire a professional to install asphalt shingles. If you are not experienced with working on roofs, you can easily make mistakes that could lead to leaks and other issues.
Conclusion
For choosing the best roof material for a home or shed, determining the roof slope is essential, whether using asphalt shingles or metal. From there, you can calculate the minimum pitch for shingles you can use. Additionally, some local building codes may have specific requirements for minimum roof slope that must be followed
