Trying to decide which type of roof to install on a commercial building can be tricky. Certain types of roofs and roofing materials are better suited for specific situations, industries and climates. The type of roofing material you choose can make a major difference in how long your roof lasts, how much maintenance it needs and the chances of it leaking or getting damaged.
Metal Roofing
If you have a commercial building with a medium or steep slope roof, metal roofing is by far one of the best options. Metal roofing provides exceptional drainage, ensuring water doesn’t pool on the roof and potentially result in leaks. Metal roofs are also extremely strong and durable, making them far less prone to storm damage than other types of roofs. Another advantage of metal roofing is that it requires basically zero maintenance other than having it inspected occasionally for leaks and damage. You can normally expect a properly installed metal roof to last for 40-50 years, which is about twice as long as shingle roofs typically last. The only real downside to opting for a metal roof is that it will cost quite a bit more to install compared to asphalt shingles.
Asphalt Shingles
Asphalt shingle roofs have some drawbacks in terms of strength, durability and longevity. Nonetheless, they are still the most common choice for commercial buildings with sloped roofs. The main reason is that shingles are the least expensive option. Many business owners also simply prefer the classic look of shingles over metal roofing.
The two main types of shingles are three-tab and architectural or dimensional. Three-tab shingles cost quite a bit less, but they aren’t nearly as strong and are more prone to storm damage than architectural shingles. If you opt for three-tab shingles, your roof will likely only last for 15 to 20 years. Architectural shingles usually last for 25 to 30 years or sometimes even longer.
Single-Ply Membranes
Single-ply membranes are one of the most popular options for commercial buildings with a flat roof or a low-slope roof. The three main types are TPO, EPDM and PVC.
EPDM is usually the least expensive option for flat and low-slope roofs. The membrane is made from synthetic rubber and is extremely flexible. The flexibility makes it highly resistant to impact damage, punctures and tears. It also makes it one of the best choices for colder climates, as the membrane can shrink without getting damaged or coming apart at the seams. Most EPDM is black, which negatively impacts the building’s energy efficiency during the summer as a result of the roof absorbing lots of heat. If energy efficiency is a concern, you can also opt for white EPDM. With proper installation, EPDM roofing usually lasts for around 20 to 30 years.
TPO is also a cost-effective option. This type of membrane is a blend of synthetic rubbers and is resistant to punctures and tears, although not quite as resistant as EPDM. The seams between each piece of membrane are heat sealed, which greatly reduces the chances of the roof leaking. TPO is almost always white, which helps keep the roof cooler and protects it from UV damage and weathering. The main drawback to TPO is that it is a relatively new material, meaning there are still some question marks as to its longevity and durability. Some products may last for around 20 years, but others may fail in as little as 10 years. TPO can also become brittle when exposed to extreme heat, which increases the chances of it getting damaged and the roof leaking.
PVC is the strongest type of single-ply membrane and usually lasts for 20 to 40 years, depending on the quality of the product. It stands up extremely well to heat and is highly efficient due to how much sunlight it reflects, making it a great choice for hot climates. It’s also resistant to corrosion and damage from chemicals and oils, which is important for restaurants and certain industries. Another great thing about PVC is that it is available in a wide range of colors, making it a more attractive option if you have a low-slope roof that can be seen from the ground. It’s also more environmentally friendly than TPO and EPDM. This is partly because less petroleum and oil are used to produce it and also because it’s fully recyclable.
The main drawback is that it costs quite a bit more per square foot than other single-ply membranes. It’s prone to cracking when exposed to freezing temperatures, making it a poor choice for colder climates.
Built-Up Roofing
Built-up roofing is the traditional option for flat and low-slope roofs. This type of roof consists of multiple layers of fabric or felt that are each coated with a layer of either asphalt or coal tar. The top of the roof is then coated with a layer of gravel that helps to reflect sunlight and protect the underlying layers.
The alternating layers create a waterproof barrier that makes the roof resistant to leaking and impact damage. It also makes the roof extremely durable. Built-up roofing typically has a lifespan of 20 to 30 years. However, with proper installation and regular maintenance, it can last for 40 to 50 years.
The biggest drawback to built-up roofing is the cost. The materials themselves aren’t that expensive. However, the installation process is labor-intensive and takes a long time, resulting in the labor costs being higher compared to other flat roofing options. Built-up roofing is also heavy, meaning the roof may need to be reinforced prior to the installation to ensure it can fully support the weight with no issues. Another concern is that improper installation can lead to numerous leaks and the roof not lasting very long. If the roof starts to leak, it can also be difficult to pinpoint and repair the problem.
Modified Bitumen Roofing
Modified bitumen has quickly grown in popularity as an alternative to built-up roofing, as it provides some of the same benefits without the drawbacks. Modified bitumen comes in pre-fabricated sheets, which allows the new roof to be installed faster compared to built-up roofing. The speed and ease of installation also cut down on the cost. Modified bitumen is flexible enough to resist puncturing and tearing, making it a good choice for roofs that experience frequent foot traffic. The sheets are also lightweight, eliminating the need to reinforce the roof structure. The life expectancy for a modified bitumen roof is around 20 years, but proper care and maintenance could allow the roof to last for up to 30 years.
While modified bitumen roofing is fairly strong, the seams can be a weak point that allows water to leak through, especially if the roof wasn’t properly installed. Most modified bitumen is black, meaning the roof will absorb more sunlight and get hotter than with built-up roofing. Modified bitumen roofs can also be more susceptible to water pooling on them.
Contact Our Trusted Experts
If you’re looking for a trustworthy, dependable commercial roofing contractor in Seattle, Spokane, Portland and Coeur d’Alene, Jimmy's Roofing is the company to call. We specialize in flat roof replacement and offer a range of options to suit the needs of any building and any type of business. We can also help if you’re looking to install metal roofing or shingles on a sloped roof.
To learn more about our commercial roofing solutions, contact Jimmy's Roofing today.
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