Commercial Roofing Options

When it comes to commercial roofing, building owners have lots of options.

Built-up roofing (BUR) systems have been in use in the U.S. for more than a century. They are so named because they are essentially “built” on the rooftop by the contractor, by alternating multiple layers of asphalt or tar between layers of felt or synthetic materials. They are often covered with gravel for protection from the elements.

The 1960s and 70s saw the development of alternatives to BUR, notably single-ply membrane roofing systems. Single-ply membranes are flexible sheets that can be manufactured from a variety of synthetic materials. Here are the most common single-ply options:

Modified bitumen membranes. These evolved from built-up roofing and are factory-manufactured layers of asphalt that are “modified’ using plastic or rubber components and reinforced with a fabric layer.

Thermoset membranes are essentially rubber, known as Ethylene Propylene Diene Monomer – EPDM. Thermoset roofing materials can’t be heat welded and require adhesives for installation seaming.

TPO (thermoplastic polyolefin) is a thermoplastic membrane that combines the flexibility and weather resistance of EPDM and the heat-weldability/chemical resistance of PVC.

PVC (polyvinyl chloride) is another thermoplastic choice. It provides excellent fire, oil, and chemical resistance, as well as excellent weathering and seaming. Because they don’t “cure” on the rooftop, they remain weldable for years after initial installation.

At Great Lakes Roofing, we prefer to install PVC single-ply systems manufactured by Duro-Last right here in Michigan. Billions of Duro-Last roof membrane has been installed across the United States, dating back more than 30 years. Not only do we believe the roof membrane is the best on the market, but we know that Duro-Last stands behind its product. Call us today at (906) 647-2916 for a free quote.

TPO PVC Flat White Roofing

PVC vs. TPO – Which Flat White Roofing Is Best?

Which type of flat white roofing is best?

As a building owner, understanding your roofing system will help you to make better decisions when it’s time for repairs and for scheduling regular maintenance. You may have purchased your commercial building after the roof was installed, so how much do you know about the type of flat white roof you have? Some basic background information about the different types of flat white roofing systems on the market will give you the knowledge to keep your roof in good condition. If your roof’s life cycle has come to an end, you’ll be better informed in choosing a new flat white roof for your building.

There are two main types of commercial flat white roofing systems on the market today, PCV and TPO. They may look very similar to the untrained eye, but there are many differences in terms of energy efficiency, formulation of materials, the way they are installed, and their costs over the entire life cycle of the roof.

What are they made of?

PVC roofing systems have been on the market since the 1960s. Polyvinyl Chloride (PVC) roofs have a membrane consisting of vinyl, UV light inhibitors, resin, heat- stabilizers, plasticizers, and biocides. The PVC membrane consists of 3 layers that are laminated together into a “single-ply”. The top layer is the performance layer. The middle layer is the weft-inserted anti-wicking scrim. The density of this middle layer is key to the strength and durability of the membrane. Duro-Last has among the highest in the PVC roofing industry with 18×14 threads per inch. For Duro-Last, a reflective white base layer is used, and all three layers are laminated together. The importance of a white base layer in terms of the Solar Reflective Index (SRI) is discussed further below. Due to the proprietary makeup of the PVC system, these roofs are strong, flexible, inherently fire retardant, and resistant to most chemicals.

TPO roofing systems were first introduced to the roofing industry in the 1980s as a lower-cost alternative to PVC. Thermoplastic Polyolefin (TPO) is made of polypropylene, ethylene-propylene rubber, and various fillers such as carbon, fiberglass, or talc mixed with polymers. A TPO roof membrane consists of 3 layers that are bound together… 2 layers of TPO that sandwich a polyester-reinforced fabric center, aka “scrim”. TPO is strong, flexible, has low flammability, and is resistant to some chemicals. However, it is less resistant to punctures and weathering than PVC. TPO is also less resistant to chemicals than PVC, so it’s not a good choice where harsh chemicals or grease are involved (restaurants, manufacturing facilities, etc.). Some TPO manufacturers use inferior formulations when fabricating their membranes, which can lead to cracking. These are all important things to keep in mind when weighing the pros and cons of PVC versus TPO roofing.

Energy Efficiency

In the past 20 years, with rising energy costs, roofing manufacturers and commercial building owners have started to increase their focus on keeping energy costs down. Having an energy-efficient roof means more than just lower energy bills…it also means a more comfortable and productive environment and lower long-term maintenance costs.

During the summer months when air-conditioning costs skyrocket, it’s important to know the Solar Reflective Index (SRI) of your roofing system. The SRI value tells you how well your roof reflects light energy, and how well it releases absorbed heat. The SRI measurement is taken when the roof is new and again when it is 3 years old. The higher the number, the better the roof is at keeping your building cool.

A white PVC roof has an initial SRI value of 108, and it decreases to 90 after 3 years. A white TPO roof has an initial SRI value of 98 and decreases to 83 after three years. Although there is not a large difference in these values, PVC is the clear winner in terms of energy efficiency.


The best measure of a sustainable roof is one that lasts a long time! PVC roofs have a long service life that cannot be matched by any other type of roof. Some PVC roofs have been in service for 30 years or more, which reduces the environmental impacts of manufacturing and shipping.  PVC roofing is the ONLY type that is recuperated in entirety at the end of decades of service life and then recycled into new roofs.

TPO roofs can last 15-20 years, however, in regions with extreme UV exposure it has been proven that their life cycle can be shortened by several years.  Once a TPO roof has reached the end of its life, it can be melted down, re-extruded, and used for the bottom ply of new membranes…however, most TPO manufacturers are not currently doing this. Between 5-15% of TPO is recycled into new roofs.

In 2009, NSF/ANSI 347 was created as a standard for measuring and evaluating the sustainability of single-ply roof systems over their entire life cycle. Each single-ply roofing system is assessed in each of the following 5 areas: product design, product manufacturing, membrane durability, corporate governance, and innovation.

Duro-Last, the leading manufacturer of PVC roofing materials, has been certified sustainable for 5 of their most popular membrane options for NSF/ANSI 347, including one gold and two silver certifications.  TPO membranes, on the other hand, have not earned the same certifications from NSF/ANSI 347.


As a commercial building owner aiming to make the best choice when selecting a new flat white roofing system, it’s a good idea to think about “value engineering”. In a nutshell, value engineering means prioritizing durability and functionality so that you end up with a roof with a long lifespan. A long-lasting roof allows you to amortize its cost over a longer period, which is a better value for you.

Any time you substitute cheaper materials, you are supposed to end up with the same performance at a lower cost. If you take the example of TPO roofing which was introduced in the 1980s as a cheaper alternative to PVC roofing, you are substituting a lower-cost material, but you are also getting a lower performance. Although TPO may cost less at the outset, you will accrue higher costs over the life cycle of the roof due to maintenance and replacement costs.

Another important cost difference to consider between TPO and PVC roofs involves the installation methods. TPO and PVC roofs can be installed using “roll goods” that are laid out on the roof and then the seams are heat-welded on site. The difference with PVC roofing is that there is an option for “custom prefabrication”.

Custom prefabrication means that the exact measurements for your roof are taken on-site, and then the entire roof is manufactured in a factory-controlled environment.  If you take the example of a Duro-Last custom prefabricated PVC roof, 80% of the seams are welded in the factory. For a 42,000 square foot roof, a typical roll goods TPO system will require 5,130 feet of seams to be made by hand, on-site. With a Duro-Last prefabricated system, only 1,278 feet of seams need to be completed in the field.

In terms of quality, durability, and cost, the factory-welded seams of a prefabricated PVC roof are superior to TPO seams that are prepared during roof installation. With TPO, time must be taken by installers while they are on the roof, to cut the membrane to size and to make the boots and stacks for the penetrations. Human error while cutting and heat-welding can create gaps and defective seams. These may not be apparent at the outset, but with time they are weak points in your roof that can result in future leaks and the costs associated with repairing them.

The custom prefabricated roof arrives ready to go, so the installation time is minimal, and you have less interruption for your business.  While the initial membrane costs of PVC are higher than that of TPO, the cost is in the membrane material, which stays with your roof. In terms of value engineering, it makes more sense as a building owner to prioritize spending on high-performance materials than spending on labor, which leaves at the end of the job.


Most commercial building owners are busy and would rather put off reading their roof warranty to a later date…usually when roof leaks occur, and they realize they need repairs. Don’t make this mistake! There are major differences in the warranties that different flat roofing system manufacturers are offering, and these could make or break your business if you have problems with your roof later on down the road. Carefully consider the warranty that is being offered with your roofing system, before deciding what type of flat roof is best for your business.

The best and most comprehensive roof warranty that we know of on the market is from Duro-Last for their custom-prefabricated PVC roof system. They offer a 15-year “No Dollar Limit” warranty with every commercial roof installation. It covers consequential damages, such as loss of business, that could occur if your roof were to leak due to faulty materials or workmanship. Duro-Last has taken extensive measures in-house to produce the very best roofing materials, then every single commercial roof is inspected by a Quality Assurance technician to ensure that the roof has been installed to Duro-Last’s high standards.  You can rest assured that for 15 years you will not have any out-of-pocket costs for roof leaks due to inferior materials or installation methods.

Call Great Lakes Roofing & Insulation

Choosing a roofing system and a roofing contractor are both very big decisions to make. Great Lakes Roofing and Insulation has been serving northern Michigan for more than 35 years. Allow us to answer your questions and assist you throughout this process. Reach out to us today at 989-575-0190.

4 Cost-Related Questions to Ask as You’re Considering a New Commercial Roof

If you’re in the market for a new commercial roof, there are many cost-related issues to consider before selecting the type of system you need and the contractor to install it. Here are some questions to think about.

  • Is your roofing project a relatively simple re-cover or does it need an expensive tear-off, new insulation, replacement of metal components or edge details, or other work? Depending on the type of system you select, it can possibly be installed right on top of the current roof (if local building codes permit), sparing you the cost of a tear-off. This is a feature of lightweight, single-ply roofing systems.


  • What experience does the contractor have with your building type and the roofing system being considered? When you buy a roof, you’re also buying the know-how to install it. Rooftops differ from building to building. Roofs on restaurants and manufacturing plants typically have lots of penetrations for venting and exhaust. A warehouse roof may be more wide-open. These differences present different challenges. Can the contractor you choose install a roof that will give you financial peace of mind now and into the future?


  • What’s the best roof system for your facility? Your answer might partly depend on how long you expect to own your building. Coatings are short-term solutions that can extend the life of a roof and improve leak protection and provide energy savings. Single-ply membranes and other systems should serve your building for at least 15 years. Another “best roof” consideration is the type of operation you’re roofing. As noted above, restaurants and some other businesses have exhaust venting onto the roof surface and some roof membrane types are highly resistant to a variety of chemicals while others deteriorate. Some systems withstand intense sunlight better than others. An expensive, durable roof may be better for your budget than a cheaper alternative that would need to be replaced sooner.


  • Can you negotiate some added value from the roofer? Some contractors may be inclined to offer a lower price on roofs installed during the slower winter months than when they are busy the rest of the year. Or if you own or manage a few commercial facilities that have upcoming roofing needs, you may be able to negotiate a multi-job discount. Consider asking the contractor for an extended warranty or a roof maintenance program that provides coverage in addition to what’s included in the initial job warranty. All these possibilities will stretch your roofing budget dollar.


At Great Lakes Roofing & Insulation, we’re all about delivering value to our commercial roofing customers. We’re able to do this because of our successful experience with a variety of building types and our commitment to quality and customer satisfaction. Please contact us to discuss your specific needs.

Lesser-Known Consequences of Commercial Roof Leaks

Aside from the inconvenience and cost of repairing leaks in your commercial roofing system, there are some potentially higher expenses that may come your way if those leaks aren’t dealt with quickly and effectively. Here are a few cases.

Roof leaks can result in water on your floor, and standing water on any surface – especially vinyl composition or hard concrete floors, like those found in many warehouses and factories – can be hazardous. There’s added risk if your operation uses industrial lubricants. Workplace slips-and-falls are a major source of worker compensation claims as well as lawsuits by building visitors.

Insects flourish in warm moist environments, and roof insulation that’s become wet from a leak can be a breeding ground. This also applies to other building materials, such as wood used in the facility’s structure and ceiling and wall materials. Hiring an exterminator to properly rid your building of these pests can be costly and disruptive to your operation.

Mold – like bugs – develops in building conditions that are warm and moist. In addition to potentially making your workers ill (resulting in lost productivity and possible workers’ comp claims), mold can cause permanent damage to building components like walls, ceilings, carpets, window treatments and more. Mold can be hard to locate and harder to remediate, often requiring the complete removal of affected areas – expensive by itself, but also potentially having a disruptive impact on your day-to-day business.

Your roof system insulation helps keep your building warm in winter and cool in summer, but if it gets wet, it loses its R-value. This reduced insulation effectiveness means that your wintertime heating and summertime cooling costs are likely to increase.

At the time they’re installed, most new commercial roofs should last at least 15 years. But water from a leak that penetrates the roof surface can shorten that expectation by damaging the deck, insulation, fasteners, and other components. Needing to invest in another new roofing system before you expected isn’t a preferable financial option.

Clearly, compared to these potentially expensive and unforeseen consequences, the cost of finding and repairing leaks in your commercial roof will be much less. Your building maintenance budget should include plans for addressing rooftop leaks.

Great Lakes Roofing & Insulation would be privileged to partner with you on any commercial roofing project you may have in the works. Reach out to us for a consult!

It’s Hail Season: What Does that Mean for Your Commercial Roof?

Hail causes damage amounting to billions of dollars’ worth of losses every year. Not surprising, given that hailstones can get pretty big – the largest on record in the US weighed almost two pounds.

Spring and summer are peak hail seasons, especially in the Midwest, so, if you have a commercial building in that part of the country, hail is likely to fall on it at some point. Even a hailstorm that’s fairly short in duration or small in scope can create damage to your flat roofing system. The extent of the damage can vary, depending on a number of factors, such as the condition and age of the roof and the material underneath (for example, insulation vs. a more rigid cover board).

Once the hailstorm has passed, make it a priority to get on your roof to inspect for damage or hire a professional contractor to assess the situation. Clear visible indicators of roof damage include depressions, tears, or cracks in the membrane. Check carefully, because small cracks and other irregularities can be hard to spot until the roof experiences subsequent weathering. Those small cracks indicate that the membrane has been weakened, and may eventually lead to leak problems.

If the surface seems ok, check rooftop metal components, like HVAC equipment, gutters, and coping, for dents.

For single-ply membrane roofs, in addition to causing immediate problems, hail can compromise the strength of the attachment or adhesion of the membrane to the underlying insulation. Depending on how the system was installed, fasteners can loosen or the adhesive bond between membrane and insulation can separate. Also, hail can dent insulation beneath the membrane, creating gaps between those components. Subsequent severe weather can cause further separation and ultimately, roof failure.

If you’re in the market for a new roof, contact us today. At Great Lakes Roofing and Insulation, we can offer roof system options that can help minimize the effects of hail on your commercial facility.

Best Roofing Contractor Practices

Your commercial roof is one of the most critical parts of the structure, and sooner or later it’s going to need replacing. When it does, it’s vital that you select the right contractor to do the work. Most post-roof-installation problems can be traced to contractor workmanship.

Here are some considerations:

  • Commercial roofing systems vary widely in their technology and how they are installed, and the contractor should have extensive experience with every aspect of the roofing system(s) being considered for the project.
  • The contractor should be trained and authorized by the roofing manufacturer. Many manufacturers have implemented quality rating and recognition programs to ensure that the contractors installing their roofing systems are proficient.
  • For re-roofing projects, the contractor should complete a thorough investigation of the current roof to uncover any problems and/or potential challenges, and then discuss findings with you. This might include cutting through the current roof to determine the condition of components (e.g., insulation) under the membrane, and doing pull tests to ensure that the correct fasteners are chosen for the job.
  • The contractor should have safety as their number one priority, both for workers and building occupants. Before the job starts, there should be an evaluation of potential jobsite safety hazards and ways to mitigate those hazards.

When you choose Great Lakes Roofing and Insulation for your project, you can be confident that your new roof will be installed with quality. Contact us today!

Proper Drainage is Critical for the Health of Your Commercial Roof

Steep-sloped roofs that are typical for single-family homes, especially in the Midwest, obviously are constructed to let water easily flow off. Flat, commercial roofs, on the other hand, although originally built with at least a modest slope, are not always as efficient at drainage. This could be because of blockage or because parts of the roof have settled and no longer have sufficient slope for water flow.

Poor or nonexistent drainage on a commercial roof is a precursor to potentially serious problems. If ponding water is not drained, it can lead to the buildup of debris, compromise rooftop seams and other membrane connection points, promote vegetation/mold growth, and cause structural damage to the facility itself (water weighs about five pounds per inch of depth, per square foot of roof surface).

The solution may be as easy as ensuring that rooftop drainage systems – drains, gutters, scuppers, and downspouts – are clear of debris and allow water to flow freely. Although intended to accomplish the same goal (moving water off the rooftop), they each function differently.

Rooftop drains channel water down through the building and out at ground level or into a sewer. Scuppers and gutters are similar, in that they both direct water off the perimeter of the roof. They should connect to downspouts that direct water down and well away from the building and walkways. At the time your building was constructed, one or more of these drainage systems were designed and installed to be appropriate for and properly integrated with the roof.

However, even the best drainage systems can become clogged over time, especially after storms or when snow has accumulated. The simple and low-cost fix: do a regular rooftop and drainage inspection to ensure that water is able to flow freely at all points.

If your roof has settled over time to where slopes have minimized or disappeared, more extensive fixes may be required. This may include adjusting the roof slope with crickets (triangular structures installed on the rooftop to direct water) or tapered insulation to eliminate ponding water by providing positive drainage. These can be typically handled by a commercial roofing contractor. Structural building damage needs the attention of a qualified facility engineer.

At Great Lakes Roofing & Insulation, we understand all aspects of commercial roofing and can help you address your rooftop drainage problems. Give us a call today! 989-575-0190

Commercial Roofing Maintenance in the Winter

Commercial roof maintenance in the winter

Don’t stop thinking about maintenance for your commercial roof when the calendar rolls around to winter. Your roof keeps your facility protected during this harsh weather season; return the favor and make sure it’s able to provide watertight protection. Here are some things to keep in mind with respect to winter roof maintenance.

Conduct occasional spot checks and inspections. This is especially important after a significant wind and/or precipitation event. Seemingly small problems can become big ones in the winter if water penetrates your roofing membrane and goes through multiple freeze and thaw cycles. In addition to membrane holes and cracks, keep an eye out for seams that may have developed gaps, especially around flashings and other transitions.

Your drains, gutters and downspouts need to be clear and running freely to carry water away from your building. Fall and winter storms can drop leaves and branches from nearby trees. This debris can clog drainage systems and when water doesn’t drain it can freeze and cause serious problems, including ice dams on shingled roofs. Make sure scuppers around your roof perimeter as well as drains on the rooftop are unblocked. Remember that falling branches can puncture roof membranes, so inspect for those issues as well.

Roof materials expand and contract with temperature fluctuations. Cold-weather stresses can compromise the integrity of membrane seams, create gaps in metal or plastic edging around the perimeter of your building and cause other problems. Your winter rooftop inspection should include documenting and repairing any issues along these lines.

When you’re on the rooftop be safe. A commercial roof can be hazardous in good weather, but it becomes much more so when it’s snow-covered and slippery.

If you’d like to leave your wintertime (or anytime) roof inspections to a professional, the roofing pros at Great Lakes Roofing and Insulation would welcome the opportunity to discuss your needs with you. Please contact us at your convenience.

The Snow on Your Commercial Roof is a Weighty Issue

If you own or manage a commercial property in the northern part of the US, you’re probably diligent about keeping it clear for customers and other building traffic. But the roof, being “out of sight, out of mind,” might get less of your attention. That can be a problem, as accumulated snow on the rooftop can create potentially hazardous issues, if your building structure can’t handle the weight.

An easy winter with minimal snowfall may not matter too much. Six inches of dry light snow weighs about a pound and a half per square foot – probably ok. But if it’s wet, heavy snow, that same six inches can weigh ten pounds per square foot. In that case, a mere hundred square feet (10×10) will add 1000 pounds to your roof. That’s a much more serious proposition and if your building structure can’t handle the weight, you’re putting people and property at risk.

During a winter with substantial precipitation, you should include visits to your rooftop as part of your maintenance plan. Because there are likely to be freeze and thaw cycles when snow will melt, make sure that your drainage system is able to handle the flow of water. Backed up drains, gutters and downspouts can cause water to pond on your roof. And if that freezes into multiple layers of ice that grows to three inches thick, that 10×10 area will carry an additional weight of 1500 pounds.

So, it makes sense to clear accumulated snow and ice from your roof. When you do:

  • Do it safely. Roofs can be unsafe when they’re clear and dry; when covered with snow, they are even more so. Crews should be especially cautious around the perimeter and near skylights, which may be hidden from view by snow.
  • Know where the snow will go. When removing it, take care not to dump it onto walkways or near doorways. You should also avoid dropping onto sensitive plantings.
  • Use the right tools. Don’t use metal shovels with sharp edges. These can damage single -ply roof membranes and then you’ll have bigger problems – especially in the spring when snow melts and water finds its way through those new holes. Also, if you’ve got ice to remove, use a product that’s compatible with your roof membrane. Check with the manufacturer on what would be appropriate.

If you have questions about wintertime roof care, please call the commercial roofing professionals at Great Lakes Roofing and Insulation 989-575-0190. We’re operating year-round to provide you with excellent service.

Make Sure You’ve Got the Right Roofing Contractor on Your Team

A successful commercial roofing installation requires a team approach. As a building owner or manager, you should include yourself in that mix, along with someone from your maintenance staff and perhaps a person who handles your organization’s financial responsibilities. Depending on how big or complex a project is, companies might bring in an architect or roof consultant for their advice.

The roof system manufacturer can also play a part, by helping you qualify installers who work with their system, helping you understand their product warranties, and being available with post-job support, if necessary, among other things.

Ultimately and obviously, the contractor who installs the roof is the most critical member of the roofing team. Make sure you choose the right one. Here are some qualities to look for.

They have a clear strategy. A new commercial roof installation can range from a relatively simple and small re-cover to a large tear-off that includes new insulation, edge details, deck sheets, parapets, and other components. Regardless of the situation, your contractor should have a plan for completing the project on time and on budget; there should be no surprises.

They are clean and organized. Your first indication of how a roofer measures up is the appearance of their sales rep and vehicle when they arrive at your facility. As the saying goes, neatness counts, and the condition of their clothing, truck and other equipment can be a reflection of the company they represent. Your roofing project will require supplies, tools, and other materials, and these should be well-organized on the jobsite. During and after the job, the roofing crew should be diligent about cleaning up tools, fasteners, membrane trimmings, packaging and other materials and equipment.

They stay in touch. Your commercial roofing project is a complex operation that can take place over several days or even weeks. The contractor you’re working with should be readily accessible and communicative from the beginning of the sales process through the completion of the job – and beyond. You’re investing a lot of money to make sure your building stays watertight for years to come; pick a contractor who is responsive to your needs.

The commercial roofing professionals at Great Lakes Roofing & Insulation bring all these qualities to every project. We would be proud to be part of your team! We look forward to your call.