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While there are certainly a number of things homeowners must consider when seeking roof repairs or replacements, commercial roofing is an even more complicated subject. This makes things difficult for commercial property managers in the Charleston area, who must not only navigate the complexity of commercial roofing but also the specific challenges Lowcountry roofs face.
We’ll try to help by outlining some of the key factors you’ll want to consider when it comes time to have your commercial roof repaired or replaced, to ensure you get the kind of results you deserve.
Charleston’s Coastal Climate: A Key Factor in Commercial Roofing Decisions
One of the very first things property managers must consider when shopping around for commercial roofing solutions is the local climate. Simply put, Charleston’s weather creates several challenges that’ll affect your choice of roof materials and options.
- High Humidity and Salty Air: The humid, salty air in the Charleston area can corrode roofs, especially the metal hardware used to keep some roofs secure.
- Intense Sunlight and UV Exposure: Charleston’s strong sunlight can take a serious toll on your roof, as it bakes in the sun all day. This highlights the importance of UV-resistant roofs (or roof coatings).
- Storms and Strong Winds: Storms are unfortunately common in Charleston, causing strong winds to pelt your roof with debris or even lift it away from the decking.
Common Commercial Roofing Systems Available in Charleston
There are several different commercial roofing systems used around the Charleston area, and it is important to learn the basics of each one to ensure you wind up with the best system for your building.
TPO (Thermoplastic Polyolefin) Roofing
One of the most popular options, TPO roofing is a highly reflective roof covering that’s especially well-suited for retail establishments, warehouses, offices, and light industrial buildings. TPO roofs include an insulation layer that’s attached to your roof deck and a coverboard that’s placed over the insulation. The actual TPO membrane is attached to the top of the coverboard.
TPO roofs feature welded seams to provide impressive moisture resistance, and they offer a good balance of cost, durability, and energy efficiency.
PVC (Polyvinyl Chloride) Roofing
Another membrane-style roof, these durable roofs feature an insulation layer and an optional coverboard layer, with a light-colored PVC membrane attached to the top.
Reflective and energy-efficient, these roofs perform well in salty, humid air and feature hot-air welded seams. This makes them an excellent choice for businesses in the Charleston region, given our area’s climate and weather patterns. PVC roofs also offer great chemical resistance, which makes them a good choice for restaurants, industrial facilities, and similar businesses.
EPDM (Ethylene Propylene Diene Monomer) Roofing
Also called rubber roofing, EPDM is similar to TPO and PVC in that they consist of an insulation layer attached to the deck and a protective membrane sheet. However, they lack the coverboard component that TPO and PVC roofs often include. EPDM roofs are a great choice for large, flat roofs, and they can handle Charleston’s heat and intense UV rays quite well.
Nevertheless, because EPDM roofs are generally dark in color and don’t reflect light well, they don’t offer the same kind of energy-efficiency benefits that TPO or PVC roofs provide. That’s why many roofers recommend having a reflective coating applied on top of the membranes.
Built-Up Roofing (BUR)
Built-up roofing consists of alternating layers of bitumen (asphalt), reinforcing felts or fabrics, and a protective top layer — often gravel, mineral cap, or a reflective coating. These layers are literally “built up” on the roof, hence the roof style’s name.
Built-up roofing is no longer as popular as it once was, and it’s not very commonly used in new installations. However, you’ll still see built-up roofs around Charleston, given the age of many of our local buildings. Despite no longer being a popular choice, built-up roofing is a time-tested option that is durable and provides great protection against foot traffic and minor impacts (such as small hail).
Modified Bitumen Roofing
Modified bitumen is a multi-layer, asphalt-based roofing system that is essentially a more flexible version of traditional built-up roofing (BUR). Modified bitumen roofing typically comes in rolls that are applied in multiple layers to create a thick, durable waterproofing layer.
Modified bitumen offers very strong puncture resistance, and it’s especially well-suited for smaller commercial roofs that experience a lot of foot traffic or require considerable durability. This makes them a popular choice for things like medical offices, restaurants, and mixed-use commercial buildings.
Standing Seam Metal Roofing
Standing seam metal roofing is somewhat similar to the corrugated metal roofs of the past, except that the metal material is generally thicker and all of the connection hardware remains hidden. This reduces the amount of maintenance required, as you don’t have to worry about washers and fasteners coming loose.
One of the best options for hurricane-prone regions like Charleston, standing seam metal roofing has excellent wind resistance and isn’t as likely as some other roofing styles to lift away from the roof deck. It also provides an attractive aesthetic, which works well in coastal areas. However, protective coatings are typically required to prevent corrosion from salty air.
Spray Polyurethane Foam (SPF) Roofing
Spray Polyurethane Foam (SPF) is a seamless, high-performance commercial roofing system created by spraying a liquid mixture of isocyanate and polyol resin onto the roof surface. The liquid expands into a rigid, closed-cell foam that forms a continuous, insulated, waterproof layer that lacks seams, thereby reducing the risk of leaks.
Because it’s sprayed in place, SPF conforms to any roof shape and fills gaps, transitions, and irregularities extremely well. It can also be installed over an existing roof in some cases, eliminating the need for a full tear-off. It also offers excellent energy efficiency, but it must be coated with a UV-resistant coating to protect it from the sun’s rays.
Choosing the Right Roofing System for Your Building Type
Knowing the different roofing systems commonly used in Charleston is important, but it’s only one part of the equation: You also need to decide which roofing system will work best for your specific building. This means:
- You need to pick a roofing system that’s suitable for the building’s use. This means considering the amount of foot traffic the roof will receive, the sensitivity of the interior operations, and any chemical resistance concerns. It’s also important to consider the way noise will affect the people inside the building.
- You must consider the roof’s slope and design. This not only means factoring in the roof’s slope but also the weight limits the building presents. Some buildings lack the structural strength necessary to support heavy roofing systems, such as metal or built-up roofing.
- You should recognize the climate and environmental demands the building experiences. By and large, these factors will remain consistent across the Charleston area, with things like heat-, wind-, and UV-resistance being important. Corrosion resistance is also important to consider for buildings along the coast.
- You have to consider your energy efficiency goals. To keep your cooling costs low, you may want to emphasize things like reflectivity and insulation (which will also help control your heating costs in the winter). And if you may want to install solar panels in the future, you’ll want to select a roof that’ll allow this kind of upgrade.
- You should always consider the long-term maintenance requirements. The ongoing maintenance of your roof is an important factor to think about when making a choice. For example, standing seam metal and TPO require minimal maintenance, while SPF, modified bitumen, and built-up roofs require periodic resurfacing.
The Cost of Commercial Roofing in Charleston
Of course, it’s also important to think about the cost of your new roof and ensure it fits in with your budget. Typical price ranges for different kinds of commercial roofs in Charleston are as follows:
- TPO / PVC / EPDM: $5 to $12 per square foot
- Modified Bitumen: $6 to $12 per square foot
- BUR (Built-Up Roofing): $7 to $14 per square foot
- SPF (Spray Polyurethane Foam): $8 to $14 per square foot
- Standing Seam Metal Roofing: $12 to $25 per square foot
However, it’s important to remember that some roofs have higher upfront costs yet require less frequent maintenance and enjoy longer lifespans. Additionally, the energy savings some roofs provide will help to offset a high initial investment.
Signs Your Commercial Roof Needs Repair or Replacement
There are a number of signs that may indicate your roof has become damaged or is in need of attention. A few of the most common signs include:
- Water stains or active leaks inside the building: One of the most visible red flags, leaks and water stains often indicate things like failed seams, flashing issues, or long-term membrane deterioration.
- Ponding water on the roof surface: Standing water that remains for more than 48 hours can weaken the roofing materials, overload the structure, and shorten the lifespan of the entire system.
- Blistering, bubbling, or membrane separation: Often caused by trapped moisture or poor adhesion, blisters and bubbles are especially common in older TPO, EPDM, modified bitumen, and BUR systems.
- Cracks, punctures, or torn membranes: Foot traffic, falling debris, or storm damage can compromise the roof’s waterproofing layer, creating physical penetrations that’ll only get worse with time.
- Loose, lifted, or missing flashing: When flashing pulls away from walls, pipes, or other roof features, water intrusion becomes highly likely, especially during Charleston’s heavy rains and hurricanes.
- Clogged or poorly functioning drainage systems: An often-overlooked source of trouble, blocked drains or scuppers can lead to ponding, structural stress, and premature failure.
- Rust, corrosion, or loose fasteners on metal roofs: Coastal salt air can accelerate corrosion, making this an important issue for Charleston property managers to monitor.
- Granule loss on modified bitumen or BUR surfaces: Look for smooth patches and granules accumulating in your gutters, as they can indicate the roof’s protective layer is deteriorating.
- Higher-than-normal energy bills: Failing and poorly insulated roofs often cause your cooling costs to steadily rise, as your building becomes more vulnerable to Charleston’s hot, humid climate.
- Age of the roof: Most commercial roofs last about 15 to 30 years, though this varies from one system to the next. Once past their expected lifespan, problems typically become more frequent and costly.
It’s also important to note that not all roofing issues will require a complete replacement. By catching issues early, you may be able to have your commercial roof repaired, rather than having to opt for a complete tear-off and replacement.
Commercial Roofing in Charleston: FAQ
Still have questions about commercial roof repairs and replacement in Charleston? We’ve rounded up a few of the most common questions we hear from our clients and answered them below.
How long do commercial roofs typically last in Charleston?
Most commercial roofs will last between 15 and 30 years in Charleston, as long as they are properly maintained. Without regular maintenance, many roofs will start to suffer damage long before reaching the end of their typical lifespan.
How often should I have my commercial roof inspected?
It’s important to have your commercial roof inspected twice each year (generally in the spring and fall), as well as after hurricanes or significant weather events.
Can I repair my existing commercial roof, or do I need a full replacement?
A variety of factors will determine whether your roof can be repaired or requires full replacement. Repairs are often possible when the damage is localized and minor, but extensive damage will often necessitate a complete tear-off and new roof installation.
What’s the best commercial roofing system for Charleston’s climate?
There is no single “best” commercial roofing system for Charleston’s climate, as each offers a different set of benefits and drawbacks. TPO and PVC offer excellent UV resistance, while standing seam metal performs best in hurricanes.
How long does a commercial roof replacement usually take?
Most commercial roof replacement projects take about one to three weeks, though the exact timeline is obviously influenced by a number of factors, such as the building size, weather conditions, and the material selected.
What type of warranty should I look for in a commercial roof?
Most roof material manufacturers guarantee their products for 10 to 30 years, and many contractors offer workmanship warranties lasting for up to 10 years. It’s important for Charleston-area businesses to look for NDL (no dollar limit) warranty coverage, given the frequency with which hurricanes batter the area.
How much should I budget for commercial roof maintenance?
As a rule of thumb, most property managers should budget 1% to 3% of the roof’s initial cost for maintenance each year. In other words, if the roof costs $100,000 to install, you’ll likely spend $1,000 to $3,000 per year on maintenance.
Willow Ash Roofing: Charleston’s Preferred Commercial Roofing Contractor
Whether you need to have your commercial roof repaired or you are considering full replacement, there’s only one name you need to know in the Charleston area: Willow Ash Roofing.
We’ve been providing industry-leading commercial roofing solutions for more than 20 years, earning an A+ rating from the Better Business Bureau and a 4.9-star Google rating during that time. We can provide the commercial roofing solutions you need so that you can focus on managing your business.
Contact us today to schedule your free on-site inspection and get a free, no-obligation estimate.
Sources & References
- Federal Emergency Management Agency (FEMA) – “Home Builder’s Guide to Coastal Construction: Wind-Resistant Roofing”
Provides federal guidance on designing and installing roofing systems that withstand hurricane-force winds, including fastening, materials, and edge detailing.
https://www.fema.gov/sites/default/files/2020-08/fema499_2010_edition.pdf - National Oceanic and Atmospheric Administration (NOAA) – National Centers for Environmental Information
Offers authoritative climate and weather data for Charleston, South Carolina, including hurricane frequency, wind speeds, rainfall, and long-term climate trends.
https://www.ncei.noaa.gov/ - National Roofing Contractors Association (NRCA) – “NRCA Guidelines for Single-Ply Membrane Roof Systems”
An NRCA best-practice technical guideline document providing detailed information on the design, materials, components, and installation practices for single-ply membrane roof systems, including configurations, membranes, insulation, and construction details.
https://simon-products.com/srproducts/ibs/tech/codes%20and%20approvals/NRCA/NRCA%20Guidelines%20for%20Single-ply%20Membrane%20Roof%20Systems.pdf - U.S. Department of Energy (DOE) – “Commercial Building Energy Efficiency Guidelines”
Outlines energy-efficiency strategies for commercial buildings, including roofing and envelope considerations that reduce energy consumption and improve performance.
https://www.energy.gov/eere/buildings/commercial-buildings-integration
