Steep-slope roofing is the conventional choice for most residential roofing projects. But, you may be curious about low-slope roofing options. Unfortunately, low-slope roofing presents multiple practical issues that homeowners should consider before installation.
What is a Low-Slope Roof?
Low-slope roofs have low slants, generally with a pitch of 3 in 12. 3 in 12 is a slope measurement meaning that the roof has 3 inches of elevation for every 12 inches of horizontal length.
Generally, low-slope roofing is used for commercial projects, but some homeowners also opt for this roofing option. Low-slope roofing often requires fewer materials to construct than high-slope roofing, making it a cost-efficient option. However, a low-slope roof can also present multiple issues for property owners.
The Top 3 Issues with Low-Slope Roofing
The flatter slope of low-slope-roofing increases the chances of water accumulating after a rain, hail, or snowstorm. This is because, with less of an angle, water can’t run off of the side of the roof as easily. Simply put, the drainage system of a low-slope roof isn’t as efficient as that of a steep-slope roof.
Standing water on a roof is called ponding, and it heightens the risk for leakage. Low-slope roofing may also experience in the case of poor flashing installation or damage to adhesion at the roof seams.
A roof leak can cause water damage throughout your home. When water seeps into your home, the ceiling and walls are at risk for mold and decay. If you suspect that your roof is leaking, it’s important to call a local roof repair expert as soon as possible to minimize further damage.
Strain From Snow and Hail
With a low-slope roof, snow can sit on the surface for far longer than it would on a steep-slope roof. The weight of the snow places strain on your roof and increases the risk for damage.
In comparison to a steep-slope roof, a low-slope roof doesn’t promote water drainage as effectively. If a few inches of snow accumulate on a low-slope roof, it will take longer for that snow to drain off. The weight of the snow can place strain on the entire structure of your home. Additionally, the moisture from the snow can place your roofing materials at risk for water damage.
Also, since low-slope roofs don’t drain as effectively as other roofing types, they’re more likely to develop ice dams in freezing temperatures.
In Colorado, we often experience snowstorms followed by bright sunshine in the winter. Under these circumstances, when snow melts and creates standing water on a roof, homeowners may experience ice dams. Ice dams develop when standing water on a roof freezes over, creating an ice ridge on the edges of the roof. This ridge traps the remaining water on your roof, putting your home at risk for leaks and water damage to insulation, walls, and ceilings.
Roof damage from high winds may be more likely with low-slope roofs. High winds can lift up components at the edge of the roof, often leading to far-reaching damage.
Wind damage to low-slope roofing is more likely in the cases of damaged adhesion, open seams, and improper flashing. High winds can pick up unsecured flashing or an open seam, putting the roof at risk for tenting or billowing. Expert roofing contractors will take special precautions during installation to adhere to local wind uplift ratings.
Other Low-Slope Roofing Considerations
The material of a low-slope roof can impact its durability. The two common roofing materials for low-slope roofs are single-ply membrane and built-up roof membranes. Talk to your local roofing contractor for other material options that can provide reliability in a low-slope roof.
The design of a low-slope roof won’t drain water as easily as a steep-slope roof. So, it’s important to carefully plan out the drainage system of any low-slope roof to reduce its risk of leakage and other water damage. Drains and scuppers can easily clog on a low-slope roof. So, you may also consider an open-edge design, which would drain water into an exterior gutter.
Low-slope roofing isn’t a practical option for most Colorado homeowners. For more roof replacement options, talk to your local roofing contractor.