Is Built-Up Roofing Still Used: 5 Key Differences

Is built-up roofing still in use today? As newer roofing technologies become available, many people have asked this question. However, built-up roofing, once the go-to solution for commercial buildings, still holds relevance today.

In this article, we will examine the role of built-up roofing in the modern world, delve into its history, discuss its materials, consider its advantages and drawbacks, compare it to modern alternatives, explore its lifespan and the maintenance it requires, consider cost considerations for installation, and look at its environmental impacts.

Is built-up roofing still used?

Yes, BUR is still used today. BUR is a traditional roofing system that has been in use for over a century. It consists of multiple layers of asphalt and bitumen alternated with reinforcing materials such as fiberglass or organic felts. The layers are built up to create a durable and waterproof membrane.

BUR provides excellent protection against the elements, including UV radiation and extreme temperatures. It is known for its longevity and resistance to wear and tear. Although newer roofing systems have emerged in recent years, BUR is still preferred in certain applications, such as low-slope roofs or areas with heavy foot traffic.

Its proven track record and cost-effectiveness make it a viable option for many buildings.

5 Key differences between built-up roofing and modern alternatives

1. Enhanced installation process

Modern roofing alternatives often feature improved installation processes compared to traditional BUR. For example, heat-welding or adhesive methods can be used to install single-ply membrane systems like TPO (thermoplastic olefin) or EPDM (ethylene propylene diene monomer). This makes installation faster and more efficient. These methods help reduce labor costs and minimize disruptions during the roofing process.

2. Lightweight materials

One key difference between built-up roofing and modern alternatives is the weight of the materials used. Built-up roofing typically involves multiple layers of asphalt and bitumen, making it relatively heavy. In contrast, modern alternatives, such as single-ply membranes or metal roofing systems, are generally lighter in weight. This can be advantageous for structures with weight limitations or for retrofitting roofs without compromising the building’s structural integrity.

3. Energy efficiency

Modern roofing alternatives often prioritize energy efficiency, offering significant advantages over built-up roofing in terms of insulation and heat reflection. For example, cool roof coatings or reflective materials used in some modern roofing options can effectively reduce the transfer of heat into the building, leading to lower cooling costs during hot seasons. This can be especially beneficial in regions with high temperatures or where energy conservation is a priority.

4. Environmental impact

Sustainability and environmental considerations have become increasingly important in the construction industry. Modern roofing alternatives tend to offer more environmentally friendly options compared to built-up roofing. For instance, some modern roofing systems incorporate recycled materials or are themselves recyclable at the end of their lifespan. Certain alternative roofing materials, such as green roofs or solar panels, can contribute to energy efficiency and reduce the overall environmental impact of the building.

5. Longevity and maintenance

While built-up roofing has a proven track record of durability, modern roofing alternatives often boast improved longevity and reduced maintenance requirements. For instance, some single-ply membranes or metal roofing systems have longer expected lifespans compared to traditional BUR. Modern alternatives may require fewer frequent inspections and repairs due to their inherent resistance to common roofing issues such as leaks or damage caused by weather conditions.

What is built-up roofing?

BUR is a traditional roofing system that has been in use for over a century. It consists of multiple layers of asphalt and bitumen alternated with reinforcing materials such as fiberglass or organic felts. The layers are built up to create a durable and waterproof membrane.

The installation process involves applying hot asphalt or coal tar pitch to the roof surface, followed by embedding layers of reinforcing material into the asphalt or bitumen. This process is repeated until the desired number of layers is achieved. The final layer is typically covered with gravel or a reflective coating to protect the roof from UV radiation.

BUR provides excellent protection against the elements, including UV radiation and extreme temperatures, and is known for its longevity and resistance to wear and tear. It is commonly used on low-slope roofs or in areas with heavy foot traffic due to its durability.

The history of built-up roofing

BUR has a rich history that dates back to the late 19th century. It originated as a response to the need for more durable and weather-resistant roofing materials. BUR was initially made using layers of tar paper and coal tar pitch, which were applied to roofs.

Over time, asphalt became the primary material used in BUR due to its superior properties and availability. In the early 20th century, the introduction of organic felts reinforced with materials like jute or rag fibers further enhanced the strength and durability of BUR systems. Throughout the years, BUR has evolved with advancements in technology, such as the use of fiberglass mats or polyester felts as reinforcing materials.

Today, BUR remains a popular choice for commercial and residential buildings due to its proven track record, longevity, and ability to withstand various weather conditions.

Built-up roofing materials: Then and now

• Tar paper: In the early days of built-up roofing, tar paper was commonly used as a base layer. It provided some waterproofing properties but lacked sufficient strength and durability.
• Coal tar pitch: Initially, coal tar pitch was used as the primary waterproofing material in built-up roofing. It offered excellent resistance to water and chemicals but had limitations in terms of availability and odor.
• Asphalt: Over time, asphalt replaced coal tar pitch as the primary waterproofing material in built-up roofing systems. Asphalt offered better flexibility, ease of application, and improved performance in various weather conditions.
• Organic felts: To reinforce the asphalt layers, organic felts made from materials like jute or rag fibers were commonly used. These felts added strength and stability to the roofing system. However, organic felts were susceptible to moisture absorption and degradation over time.
• Fiberglass mats: Fiberglass mats gradually replaced organic felts as a reinforcing material in built-up roofing. Fiberglass mats are more resistant to moisture and provide better dimensional stability, enhancing the overall strength and longevity of the roofing system.
• Polyester felts: Alongside fiberglass mats, polyester felts have also emerged as an alternative reinforcing material in modern built-up roofing systems. Polyester felts offer similar benefits to fiberglass mats, including improved resistance to moisture and greater durability.

Advantages of using built-up roofing

• Durability: BUR systems are known for their durability and long lifespan. The multiple layers of asphalt and reinforcing materials create a strong and resilient membrane that can withstand various weather conditions, including UV radiation, extreme temperatures, and heavy foot traffic.
• Waterproofing: BUR provides excellent waterproofing capabilities, keeping the underlying structure dry and protected from water infiltration. The layers of asphalt and bitumen create a barrier that effectively prevents water from penetrating the roof.
• Fire resistance: Built-up roofing systems have inherent fire-resistant properties. The multiple layers of asphalt and bitumen offer a high degree of fire resistance, providing an extra layer of protection for the building and its occupants.
• Versatility: BUR is versatile and can be installed on different types of roofs, including flat or low-slope roofs. It can be customized to meet specific design requirements and can accommodate rooftop equipment, such as HVAC units or solar panels, without compromising its performance.
• Cost-effective: Built-up roofing is often considered cost-effective compared to some modern roofing alternatives. The availability of materials, relatively straightforward installation process, and long lifespan contribute to its affordability over the life of the roof. BUR may require less frequent maintenance and repairs, further reducing long-term costs.

Drawbacks of built-up roofing systems

• Weight: BUR systems can be heavy due to the multiple layers of asphalt and reinforcing materials. This weight can pose challenges for structures with weight limitations or for retrofitting roofs without compromising the building’s structural integrity.
• Installation complexity: BUR installation can be more complex and time-consuming compared to some modern roofing systems. The process involves multiple steps, including heating and layering asphalt, which requires skilled labor and specialized equipment. This complexity can lead to longer installation times and potentially higher labor costs.
• Vulnerability to ponding water: If not properly designed or maintained, BUR systems may be susceptible to ponding water, where water accumulates and does not drain properly. Ponding water can cause premature deterioration of the roofing materials, leading to leaks or structural damage if not addressed promptly.
• Limited insulation options: Traditional BUR systems may have limited insulation options compared to some modern roofing alternatives. While additional insulation can be added during installation, it may require additional layers or materials, which can increase the overall weight and complexity of the roofing system.
• Environmental considerations: The use of asphalt and bitumen in BUR systems raises environmental concerns due to their petroleum-based nature. Extracting and manufacturing these materials have associated carbon emissions and environmental impacts. However, it’s worth noting that advancements have been made in developing more sustainable and eco-friendly roofing materials for BUR systems.

Comparing built-up roofing to modern alternatives

Aspects	Built-Up Roofing (BUR)	Modern Alternatives
Installation	Complex, labor-intensive	Often simpler, faster
Weight	Relatively heavy	Lightweight options are available
Energy Efficiency	Moderate insulation value	High energy efficiency options
Environmental Impact	Petroleum-based materials	More sustainable options
Lifespan	Long-lasting with proper maintenance	Varies depending on material

From the table, several insights can be gathered when comparing BUR to modern alternatives:

• Installation: BUR requires a complex and labor-intensive installation process compared to modern alternatives, which often offer simpler and faster installation methods.
• Weight: BUR is relatively heavy due to multiple layers, while modern alternatives provide lightweight options, which can be beneficial for structures with weight limitations.
• Energy efficiency: Modern alternatives often offer higher energy efficiency options compared to BUR, as they may incorporate advanced insulation materials or reflective coatings.
• Environmental impact: BUR typically utilizes petroleum-based materials, contributing to environmental concerns. In contrast, modern alternatives offer more sustainable options, including recycled materials or environmentally friendly roofing systems like green roofs or solar panels.
• Lifespan: With proper maintenance, BUR can have a long-lasting lifespan. However, the lifespan of modern alternatives varies depending on the specific material chosen.

How long does built-up roofing last?

BUR systems, when properly installed and maintained, can have a lifespan ranging from 20 to 30 years or more. The longevity of a BUR system depends on various factors, including the quality of materials used, the installation technique, the climate conditions, and the level of maintenance.

Regular inspections, prompt repairs of any damages or leaks, and periodic recoating or resurfacing can significantly extend the lifespan of a BUR roof. Factors such as exposure to extreme weather conditions, poor drainage, or foot traffic can impact the durability of the roof. Individual circumstances may vary, and consulting with a roofing professional can provide a better estimate based on specific conditions and maintenance practices.

Proper maintenance for built-up roofing systems

1. Regular inspections: Schedule routine inspections by a professional roofing contractor to identify any signs of damage, such as cracks, blisters, or loose seams. Inspections can help detect issues early on and prevent them from escalating.
2. Cleaning and debris removal: Keep the roof clean by removing any debris, leaves, or branches that can accumulate and block drainage pathways. This helps prevent ponding water and potential damage to the roofing materials.
3. Prompt repairs: Address any identified issues promptly to prevent further damage and minimize the risk of leaks. Apply the appropriate patching materials or coatings in order to repair damaged areas, such as cracked or blistered sections, in accordance with the manufacturer’s recommendations.
4. Recoating or resurfacing: Consider recoating or resurfacing the BUR system when the asphalt layers start to show signs of deterioration or wear. This process involves applying a new layer of bitumen or protective coating to enhance water resistance and extend the roof’s lifespan.
5. Maintaining proper drainage: Ensure that gutters, downspouts, and other drainage components are clear of debris and functioning properly. Adequate drainage prevents water from pooling on the roof surface, reducing the risk of leaks and structural damage.
6. Plans for professional maintenance: Take into account joining a plan for professional maintenance that roofing contractors are offering. These plans typically include regular inspections, maintenance, and priority service, ensuring that your BUR system receives proper care and attention over time.

Cost considerations for built-up roofing installations

When considering the cost of BUR installations, various factors come into play. The cost can vary depending on factors such as the size and complexity of the roof, the quality of materials used, the location, and the labor involved. As a general guideline, the cost of BUR installations can range from $8 to $12 per square foot.

When comparing the cost of BUR to modern roofing alternatives, such as single-ply membranes or metal roofs, you have to consider that modern options may have a wider range of costs. Generally, modern roofing alternatives can range from $5 to $15 per square foot, depending on the chosen material and installation complexity.

It’s recommended to consult with roofing contractors and obtain multiple quotes to get a more accurate cost assessment tailored to your specific project needs and location.

Environmental impacts of built-up roofing

The environmental impacts of BUR primarily stem from the use of petroleum-based materials, such as asphalt and bitumen, in the roofing system. The production and transportation of these materials contribute to carbon emissions and energy consumption.

The disposal of BUR materials at the end of their lifespan can pose environmental challenges. However, advancements in the roofing industry have led to the development of more sustainable BUR options, including the use of recycled materials and environmentally friendly coatings. Furthermore, BUR systems can support energy efficiency through reflective coatings that reduce heat absorption, thereby lowering cooling demands.

When evaluating the environmental impacts of BUR, you need to consider the overall lifecycle of the roofing system, including its durability, energy efficiency, and potential for recycling or reuse at the end of its service life.