The Ultimate Guide to Low-Slope and Flat Roofing Materials in Southeast Michigan

The Ultimate Guide to Low-Slope and Flat Roofing Materials in Southeast Michigan

When it comes to protecting your home or commercial property in Southeast Michigan, the roof is one of the most important investments you’ll ever make. While pitched roofs with asphalt shingles are common in our area, many properties—especially commercial buildings, industrial facilities, apartment complexes, and even some modern residential homes—feature low-slope and flat roofing systems.

Flat and low-slope roofs bring a unique set of challenges. Because water doesn’t naturally shed as easily as it does on a steep-slope roof, the choice of roofing material is critical to long-term durability and performance. Over my 20+ years of experience working with roofing systems in Michigan’s climate, I’ve seen first-hand how the right material can extend the lifespan of a flat roof—and how the wrong choice can lead to constant repairs, leaks, and costly water damage.

In this guide, we’ll break down the most common flat and low-slope roofing materials, their pros and cons, and which systems tend to perform best in Metro Detroit’s weather conditions—from snowy winters in Ann Arbor to humid summers in Sterling Heights.

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Why Material Choice Matters More in Southeast Michigan

Before diving into the materials, it’s important to understand why low-slope roofing requires special attention in Michigan:

• Freeze-thaw cycles: Southeast Michigan winters bring snow, ice, and frequent temperature swings. Water that sits on a roof can freeze, expand, and damage seams or membranes.

• Heavy snow loads: Flat roofs often hold snow longer than pitched roofs, adding weight and creating drainage challenges.

• Storms and wind: Strong winds off the Great Lakes can lift poorly installed materials or damage seams.

• Heat and humidity: Hot summers can cause roofing materials to expand and contract, testing their flexibility and durability.

This climate makes the right material selection essential. Now, let’s look at the most common options.

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1. Built-Up Roofing (BUR)

Built-Up Roofing, often called “tar and gravel” roofing, is one of the oldest flat roofing methods still in use today. It’s made of multiple layers of asphalt (bitumen) alternated with reinforcing fabrics, topped with gravel or a reflective coating.

Pros of BUR:

• Durability: Multiple layers provide extra protection against punctures and leaks.

• UV protection: The gravel topcoat protects against sunlight and heat damage.

• Good for heavy traffic: Works well on roofs that see foot traffic (like maintenance areas).

• Proven system: Decades of use mean contractors know how to install and repair it effectively.

Cons of BUR:

• Weight: BUR systems are heavy, requiring a strong roof deck.

• Installation mess: Hot asphalt application can be messy, smelly, and disruptive.

• Cost: More labor-intensive than single-ply systems.

• Not as energy-efficient: Unless topped with reflective coatings, BUR tends to absorb heat.

Southeast Michigan Verdict:

BUR is still used on many commercial buildings around Detroit and Flint, but it’s less common in new construction. The weight and installation challenges make it less attractive today, especially compared to modern membranes.

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2. Modified Bitumen Roofing

Modified bitumen is essentially an updated version of BUR. It uses asphalt reinforced with fiberglass or polyester and modified with plastic or rubber additives to improve flexibility. It can be applied with torches, adhesives, or even cold-applied systems.

Pros of Modified Bitumen:

• Flexibility: Better at handling freeze-thaw cycles common in Michigan.

• Easier installation: Can be installed in sheets, reducing installation time.

• Durability: Resistant to tears and punctures.

• Reflective options: Available with “cool roof” coatings for energy efficiency.

Cons of Modified Bitumen:

• Seam vulnerability: Like BUR, seams are potential weak points if not installed properly.

• Limited lifespan: Typically lasts 15–20 years, less than some modern membranes.

• Torch application risks: Torch-applied systems can be a fire hazard if not done by experienced crews.

Southeast Michigan Verdict:

Modified bitumen is a solid mid-tier option, especially for smaller commercial buildings in areas like Ferndale or Dearborn. It performs well in freeze-thaw conditions but isn’t as long-lasting as newer single-ply systems.

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3. EPDM (Ethylene Propylene Diene Monomer)

EPDM, often referred to as “rubber roofing,” is one of the most popular flat roofing systems in the U.S. It comes in large rolls of black synthetic rubber, typically installed in a single layer.

Pros of EPDM:

• Longevity: Can last 20–30 years with proper installation.

• Proven in Michigan: Extremely resistant to cold weather and freeze-thaw cycles.

• Cost-effective: Generally less expensive than other membranes.

• Easy to repair: Tears or punctures can be patched quickly.

Cons of EPDM:

• Black color: Absorbs heat in summer, which can drive up cooling costs unless coated with reflective paint.

• Seam reliance: Seams are glued, taped, or heat-welded, and can fail if not done right.

• Puncture risk: Though durable, sharp objects or heavy foot traffic can puncture it.

Southeast Michigan Verdict:

EPDM is an excellent choice for Michigan’s climate. It’s common on schools, warehouses, and apartment buildings across the Detroit metro. For residential applications, reflective coatings may be necessary to reduce summer heat absorption.

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4. TPO (Thermoplastic Polyolefin)

TPO roofing is a single-ply white membrane that has become increasingly popular in recent decades. It’s known for its reflective, energy-efficient surface.

Pros of TPO:

• Energy efficiency: White surface reflects heat, reducing cooling costs in summer.

• Durable seams: Seams are heat-welded, creating strong bonds.

• Lightweight: Easy to install compared to BUR or modified bitumen.

• Affordable: Priced competitively with EPDM.

Cons of TPO:

• Variable quality: TPO formulations vary by manufacturer; some early versions had issues with cracking.

• Not as proven long-term: While popular, TPO hasn’t been around as long as EPDM.

• Cold weather concerns: Some TPO products don’t perform as well in prolonged freeze-thaw conditions.

Southeast Michigan Verdict:

TPO is very popular in Southeast Michigan for commercial and residential flat roofs, particularly in cities like Ann Arbor where energy efficiency is a major concern. However, it’s important to choose a reputable brand and experienced installer to avoid premature failure.

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5. PVC (Polyvinyl Chloride)

PVC roofing is another single-ply membrane similar in appearance to TPO but made of different chemical compounds. It’s often used in restaurants and industrial facilities because of its chemical resistance.

Pros of PVC:

• Chemical resistance: Excellent against grease, oils, and chemicals—perfect for restaurants or factories.

• Durable seams: Heat-welded seams are strong and watertight.

• Longevity: Can last 20–30 years.

• Reflective surface: White PVC helps reduce heat absorption.

Cons of PVC:

• Cost: More expensive than EPDM or TPO.

• Plasticizer migration: Over time, PVC can become brittle if not properly formulated.

• Not ideal in extreme cold: PVC can shrink or crack in prolonged freezing conditions if not installed correctly.

Southeast Michigan Verdict:

PVC works well for specialized buildings, especially restaurants in places like Royal Oak or Detroit where rooftop grease vents are common. For general flat roofs, it’s less common due to cost and cold-weather brittleness.

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6. Spray Polyurethane Foam (SPF)

Spray Foam Roofing involves spraying a liquid polyurethane that expands into a solid foam, then coating it with a protective layer. It creates a seamless, insulated surface.

Pros of SPF:

• Seamless: No seams to fail, reducing leak potential.

• Insulating value: Adds significant R-value, improving energy efficiency.

• Lightweight: Adds little weight compared to BUR.

• Repairable: Damaged areas can be re-coated easily.

Cons of SPF:

• Installation sensitivity: Requires skilled applicators; poor installation leads to failure.

• UV protection needed: Foam must be coated regularly to avoid UV breakdown.

• Weather limitations: Can only be applied in certain conditions (not too cold, windy, or humid).

Southeast Michigan Verdict:

SPF roofing can perform very well here, especially for large commercial buildings looking for energy savings. However, finding an experienced contractor in Michigan is key—bad installation leads to major problems.

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7. Metal Roofing for Low-Slope Roofs

While metal roofing is more common on pitched roofs, standing seam metal panels can be used on certain low-slope applications.

Pros of Metal:

• Durability: Can last 40+ years with proper maintenance.

• Aesthetics: Clean, modern look.

• Snow shedding: Handles Michigan snow loads well.

Cons of Metal:

• Slope limitations: Not suitable for completely flat roofs.

• Seam and fastener issues: Potential for leaks at seams if not installed correctly.

• Cost: Higher upfront investment.

Southeast Michigan Verdict:

Metal can work on low-slope residential applications in suburban areas like Novi or Birmingham, but it’s less common for flat commercial roofs.

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Comparing Flat Roofing Materials

Here’s a quick comparison for Southeast Michigan property owners:

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Final Thoughts: Choosing the Right Flat Roof for Southeast Michigan

Every roofing material has its strengths and weaknesses. The best choice for your Southeast Michigan property depends on your priorities:

• For affordability and proven cold-weather durability: EPDM is hard to beat.

• For energy efficiency in hot summers: TPO or PVC are excellent.

• For restaurants or chemical-heavy environments: PVC stands out.

• For long-term investment: Metal or SPF may be worth the higher upfront cost.

Most importantly, no material will perform as intended without expert installation. In Michigan, where weather conditions push flat roofs to their limits, working with a local, experienced roofing contractor makes all the difference.

If you’re considering a flat or low-slope roofing project in **Southeast Michigan—whether in Detroit, Ann Arbor, Bloomfield Hills, or anywhere in Oakland, Wayne, or Macomb counties—consult with a roofing expert who understands our climate and can recommend the right system for your specific needs.