Pros & Cons of Built-Up Roofing vs. Other Commercial Systems

Choosing the right commercial roofing system is one of the most critical decisions that a property owner or facility manager can make. Among the available options, built-up roofing (BUR) has earned a reputation for long-term durability due to its layered construction and reliable waterproofing.

However, many building professionals are now considering modern systems such as TPO, EPDM, spray foam, and metal for their unique performance benefits. Understanding how BUR compares to these options is essential when evaluating roof performance, lifecycle cost, and overall building protection.

Built-up roofing provides excellent protection through its multiple layers of bitumen and reinforcing fabrics. It offers proven resistance to weather, foot traffic, and fire. While these characteristics make BUR a dependable solution, newer commercial roofing systems bring other benefits to the table. Each option—whether TPO for its reflectivity, EPDM for flexibility, spray foam for insulation, or metal for structural integrity—offers distinct advantages. By comparing these systems in real-world conditions, decision-makers can better assess which solution aligns with their building goals and budget.

This article explores how built-up roofing performs in comparison to other major commercial roofing systems. RN Roofing provides commercial roofing expertise throughout Long Lake, MN, and has extensive experience installing and maintaining BUR and alternative systems. With insight into the factors that affect roofing performance and cost over time, this guide helps clarify the strengths and weaknesses of each option.

Built-Up Roofing vs. TPO: Which System Lasts Longer?

Built-up roofing (BUR) and thermoplastic polyolefin (TPO) are widely used commercial systems, each with different strengths in longevity. BUR systems typically last 20 to 30 years, depending on weather exposure, number of plies, and maintenance. Their multi-layer bitumen and felt composition offers built-in redundancy, making them resistant to water intrusion and mechanical damage over time. Because the layers create a thicker and denser barrier, BUR tends to degrade slowly, especially in colder climates where UV exposure is limited.

TPO roofing, while a newer single-ply membrane technology, is engineered to reflect UV rays and reduce thermal expansion, which can extend its usable life to 15–25 years with proper installation and upkeep. It is especially popular in warmer climates due to its energy efficiency. However, TPO membranes are thinner than BUR systems and more susceptible to punctures or seam failures without reinforced maintenance schedules.

BUR is generally considered more durable over time in terms of mechanical integrity and redundancy, especially for facilities with heavy rooftop traffic. For buildings in harsh environments or those needing long-term stability, built-up roofing remains a reliable and proven option.

Comparing Fire Resistance: BUR vs. EPDM

Fire resistance is a major concern for commercial property owners, especially in manufacturing zones or densely developed areas. BUR systems are among the most fire-resistant roofing options available due to their layered composition of bitumen and aggregate surfacing. The surface layer, often made of gravel or mineral cap sheets, serves as a flame-retardant barrier, which can significantly slow the spread of fire across the roof deck.

EPDM (ethylene propylene diene monomer) roofing, on the other hand, is a single-ply synthetic rubber membrane that is inherently combustible unless treated with special fire-retardant additives. While manufacturers often offer EPDM with fire-rated assemblies, its single-layer structure provides less defense against high heat or flame penetration. In terms of default fire performance, BUR outperforms EPDM under most testing protocols such as ASTM E108 Class A ratings when installed with appropriate cover boards and surfacing materials.

For buildings that require enhanced fire protection due to occupancy type or insurance standards, BUR systems provide higher passive resistance. This makes BUR a suitable choice for facilities with elevated risk profiles or those under strict fire safety codes compared to standard EPDM assemblies.

Installation Time Differences Between BUR & Metal Roofing

Installation time is a key variable in commercial projects, often tied to building occupancy schedules and labor costs. BUR systems require a labor-intensive process involving multiple layers of bitumen and felt, applied in hot or cold adhesives. Each layer must be properly bonded and cooled before the next is applied.

This multi-step installation means BUR typically takes longer to install than most other systems, often spanning several days or weeks, depending on roof size and complexity.

In contrast, metal roofing systems—typically made from standing seam panels or corrugated sheets—are pre-fabricated and mechanically fastened to the roof structure. Because the panels are custom-sized and pre-cut, metal roof installation is faster and more straightforward than BUR. Roofing crews can often complete a metal installation in significantly less time, especially on open, unobstructed roof decks. However, roof detailing and flashings can extend timelines if not pre-engineered correctly.

While BUR installation requires more on-site labor and time, the trade-off is often in durability and layered waterproofing. Project timelines must account for these differences when selecting between BUR and metal roofing systems, especially when project delays or business downtime are a concern.

Insulation Comparison: BUR vs. Spray Foam Roofing

When evaluating roofing systems based on insulation performance, BUR and spray polyurethane foam (SPF) provide very different approaches. BUR systems use rigid insulation boards installed beneath the bitumen layers. These boards—typically polyisocyanurate (ISO) or expanded polystyrene (EPS)—are mechanically fastened or adhered to the deck and offer R-values around R-5.6 to R-6.5 per inch. The insulation value depends on board thickness and continuity across the roof.

Spray foam roofing provides continuous insulation with high thermal resistance. Applied as a liquid that expands into foam, SPF conforms to irregular surfaces and eliminates gaps, which reduces thermal bridging. With an R-value of approximately R-6.5 per inch, SPF insulation often outperforms rigid boards by creating an air-tight seal that helps regulate interior temperatures more efficiently.

Additionally, spray foam acts as both insulation and waterproofing in a single system, which simplifies installation layers and reduces total roof thickness.

While BUR systems are effective insulators when paired with proper underlayment, spray foam roofs excel in delivering seamless thermal envelopes. Facilities prioritizing energy efficiency or that face extreme temperature swings may benefit from SPF’s superior insulating characteristics when compared to traditional BUR setups.

Which Commercial Roofing System Delivers the Best ROI?

Return on investment (ROI) is a top consideration for commercial roof replacement or new construction projects. Built-up roofing provides a strong ROI for large-scale buildings due to its long lifespan, high durability, and minimal maintenance over time. The initial cost may be higher due to labor and materials, but this is often offset by its 25–30 year life cycle and strong performance in weather resistance, fire protection, and load tolerance.

TPO and EPDM systems offer lower upfront costs, which can be appealing in short-term ownership scenarios or for property managers looking to stay within a tight capital budget. However, their long-term performance may include more frequent maintenance and earlier replacement.

Spray foam systems also offer good ROI through energy savings and fast installation, but their vulnerability to mechanical damage may increase lifecycle costs without regular upkeep.

Metal roofs, while one of the highest in initial cost, can last over 40 years and require minimal maintenance, making them ideal for owners seeking longevity and low operating expenses.

For large buildings with consistent climate exposure and foot traffic, BUR remains one of the most cost-effective systems over time. When balancing cost, lifespan, and performance, RN Roofing helps customers determine the best solution for long-term value. 

Get Expert Help from RN Roofing

RN Roofing has decades of experience helping business owners and property managers in Long Lake, MN, and beyond, navigate these complex choices. With in-depth knowledge of built-up roofing and all major commercial systems, the team at RN Roofing works closely with clients to evaluate structural needs, climate considerations, and financial priorities. Whether you’re replacing an aging roof or planning a new construction project, their detailed approach ensures no factor is overlooked.

If you’re ready to take the next step or need expert guidance on the right solution for your commercial property, reach out to RN Roofing for a free estimate. We can be reached by phone at 952-334-3702. Don’t leave your building’s protection to chance—let RN Roofing help you make the best decision for long-term performance and peace of mind.