Flat and low-slope designs need roofing materials to handle water pooling without risking leaks in the rest of the structure. Rolled roofing products allow for the complete coverage of even the flattest roof design. It’s available for commercial and residential buildings, although you’ll rarely find it used to cover a home. Instead, it’s more commonly used for accessory structures like sheds, garages, and carports.
The materials used on commercial buildings are affordable and can be installed quickly for a re-roofing process that only takes hours rather than days. Explore the benefits of this adaptable roofing to decide if it might work well for you.
The Two Types of Rolled Roofing
All rolled roofing is intended for use on a low-slope roof or a flat roof. It doesn’t handle steeper slopes because that kind of roof structure exposes it to wear from moving water and wind. Both main types of rolled roofing seal tightly to help water reach the roof drains without allowing any leaks.
Mineral-surfaced Rolled Roofing
This material is similar in some ways to asphalt shingles because it comes as a flexible asphalt bitumen backing with a layer of protective mineral granules on top. However, this material is applied in large rolls that cover a hundred square feet or more.
The mineral coating protects the backing from UV exposure and provides a standard residential roof appearance. It’s an affordable and quick way to cover a low-slope roof, but it’s not the longest-lasting material you can choose.
Smooth-surfaced Rolled Roofing
Commercial-level rolled roofing is made from bitumen with chemicals like atactic polypropylene (APP) and styrene-butadiene-styrene (SBS). This makes the materials quite flexible, durable, and long-lasting. One option is a form of synthetic rubber, while the other is considered a plastic product.
Both require hot asphalt mopping or solvent adhesives to seal their seams and attach them to the roof deck. Gravel ballasts are also commonly applied on top to block UV rays and add wind protection. This is a heavy-duty rolled roofing option that requires professional expertise.
Benefits of Rolled Roofing
There are many potential benefits of rolled roofing, especially for roof replacement on an existing low-slope or flat roof.
- Cost-effective: It’s one of the most affordable low-slope roofing materials, especially among those available to homeowners.
- Durability: Despite being easy to install and affordable, rolled roofing can last for 15 years or longer with proper care.
- Waterproofing: Applying large sheets of solid bitumen material reduces the number of seams over the surface of the flat roof. This provides excellent waterproofing protection, one of the main concerns with a roof design that can accumulate water before it has a chance to drain away.
- Easy installation: Unlike most other flat roofing materials, rolled roofing is easy for homeowners to install. DIY installation for granule-coating materials can involve cold adhesives or quick peel-and-stick roofing products. Hot asphalt and fasteners are usually only needed for commercial installations.
- Low maintenance: Aside from routine inspections and periodic cleaning, rolled roofing requires minimal maintenance. You can easily seal the exposed seams on residential flat roofs with new applications of roofing adhesive as needed.
Considerations for Rolled Roofing
Before committing to the installation of asphalt roofing, you need to consider if it’s the right choice for your commercial or residential building. Not all roof designs work well with rolled roofing. It’s designed only for use on low-slope roofs, specifically those with a slope of 2:12 or below. Even some commercial roofs that look flat can have a steeper slope than that. Ensure that the roof has an appropriate drainage system for this kind of roofing as well.
Rolled roofing is tough, but it’s not the best choice for extreme heat and cold. The mineral-covered kind is also susceptible to hail damage if it’s a regular problem. Ballast-covered commercial rolled roofing is hail and wind-resistant, yet it’s still prone to buckling under extreme heat or cold. Other flat roofing types may work better in harsh climates.
This kind of roofing is often advertised as DIY-friendly. That’s true for the mineral-capped kind used for residential accessory roofs, but it does not apply to the heavy-duty rolled roofing used for commercial installations. The need for torches and hot asphalt makes commercial rolled roofing only appropriate for professional installation.
Installation Options for Rolled Roofing
There are a handful of installation options for rolled roofing. Most of the methods for installing mineral-capped roofing are DIY-friendly, but the methods used for commercial installation are best left to professional roofing contractors.
Peel and Stick Roofing
The most DIY-compatible installation option requires mineral-covered rolled roofing that is already coated in adhesives. You peel away the backing cover and carefully align the material on the roof, pressing it down and overlapping each layer to create a waterproof surface. There’s no need for messy adhesives or sources of heat.
Cold Adhesive Installation
If you want more control over the amount of adhesive or don’t want to worry about sticking the material down at the wrong angle, try mineral-capped rolled roofing and a few gallons of cold adhesive. It doesn’t need heating to seal the seams between the overlapping edges of the material.
Torch Down Roofing
Torch down roofing eliminates the need for other adhesives because the bitumen backing is melted together right on the roof along each seam. This can damage the roof deck if it’s not handled correctly. Only professional installers can install this kind of flat roof surface.
Hot Mopped Asphalt
Instead of applying heat directly to the roofing membranes, some installers heat asphalt-based adhesives and apply them with a mopping-like process. This creates a well-sealed seam that can last as long as the lifespan of the material.
Mechanical Fasteners
While mechanical fastening is part of most rolled roof installations, it’s only a secondary option for rolled roofing to increase strength. Adhesive or torch down applications are still needed to seal the seams for waterproofing.
Rolled Roofing — Maintenance and Repair
Rolled roofing needs inspection at least once every six months. Check for tears, punctures, loose seams, wrinkled or lifting material, or any other signs of damage. Brush off debris with a soft-bristled push brush and clear away any drains. Wash the surface with a mild soap product and water, checking for water pooling and signs of leaks.
If you notice any minor tears or punctures, you can use asphalt-based cement and patching materials to solve the problem. More extensive damage to bitumen roofing needs the help of a professional roofer.
Find the Best Option for You
Compare your rolled roofing options to the other low-slope roof surfaces on the market today. If you’re still not sure what will work best for your complex flat roof design or aging structure, consult a professional roofing contractor for advice tailored to your situation.