Low slope roofing, explained: Applications, materials and standards
Low slope roofing has slightly different material and structural needs than steep roofing—the low pitch of the roof means that water rolls more slowly off the surface. Additionally, low slope roofing systems more directly face the sun. This means special care must be taken when selecting low slope roofing material, and during its installation.
Generally speaking, a roof with a low slope is that which has a pitch—measured as a ratio of height to width—less than 4:12. The National Roofing Contractors Association recommends that roofing systems selected for low slope roofing applications have three characteristics: weatherproofing layers, reinforcement and surfacing, which are expanded upon below. Basically, your low slope roofing system needs to be resistant to the environment, water, ice, and temperature.
Every roofing system is different, so a qualified roofing contractor is best qualified to evaluate your specific low slope roofing system’s needs when it comes time for installation or repair. But here’s a quick run-through of what to consider when choosing a low slope roofing material:
- NRCA recommends roofing for weatherproofing, reinforcement, surfacing
As mentioned above, the NRCA prescribes three characteristics that quality low slope roofing systems must account for: weatherproofing layers, reinforcement, and surfacing. These needs can be satisfied through inherent qualities of the membrane or material, or they can come from underlayments or coatings. Or, perhaps, a component of the system has more than one quality—or all three—accounted for.
Typically, shingles—and other common residential roofing materials—can be used for low slope roofing within the range of 2:12 to 4:12. Low slope roofing system with a pitch less than 2:12, though, often requires roofing materials specialized in protecting flat roofs, such as built-up roof (BUR) membranes, certain variations of metal roofing or single-ply membranes. A certified roofing contractor should be able to guide you toward the best choice for your home’s needs.
- Low slope roofing standards, explained
As with all other roofing applications, standards are created by independent rating agencies. Low slope roofing systems are dictated by the American Society for Testing and Materials (ASTM) under the ASTM D6630. In order to pass, the standard provides that a low slope roofing system prove a ”minimum level of performance” during a series of rigorous tests. There are also several design provisions which are intended to address safety, endurance and performance concerns.
If you think it might be time to replace your low slope roofing system—or replace it entirely—then consider scheduling a free roof analysis with Wildwood Roofing & Construction, St. Louis’ trusted roofing experts for years.
We will schedule a time to come out to your home and look at your low slope roofing system, and then give you an honest quote for the work that needs to be done. And, if your roof seems to be in fine working condition, we’ll tell you.
It’s just a free consultation. No risk. No obligation.
Drop us a line to tell us your project goals. We’ll tell you how we can exceed them.