The roof is the most critical component when constructing a building. It serves as the first line of defense against weather elements and plays a crucial role in maintaining the structural integrity of the building. Two popular roofing systems are single-ply roofing and built-up roofing. Each has advantages and disadvantages.
This guide will explore single-ply roofing vs. built-up roofing. Read on!
Single ply roofing
Single-ply roofing is the preferred choice for low-slope commercial roofing in North America due to its durability, longevity, and ease of installation. This roofing type dates back to the early 1960s when the first EPDM rubber roofs were installed.
Today, there are two main types of single-ply roofing material:
Thermoplastics use TPO or PVC membranes, which offer excellent weathering performance and resistance to UV, tears, punctures, and most chemicals. Thermoplastic membranes are seamed using hot air welders to melt the plastic and pressure to join sheets. TPO roofing systems are the fastest-growing segment of the commercial roofing industry. They are often used in southern climates due to their light-colored and ENERGY STAR® qualified properties, which help reduce cooling costs. PVC roofing systems are also popular and offer excellent resistance to rooftop chemicals, including acids, oils, and greases.
Thermoset roof systems are typically EPDM rubber, highly resistant to ozone, ultraviolet light, weathering, high heat, and abrasion damage. EPDM membranes are seamed using pressure-sensitive tapes to join two sheets together. EPDM roofing systems are ideal for many climates due to their low maintenance, easy repairability, and top-notch weathering characteristics. While traditionally black, white EPDM membranes are also available and offer reduced heating costs during winter in northern climates.
Advantages of single-ply roofing
- One of the primary benefits of single-ply roofing is its lightweight nature.
These roofing systems are easy to install and can reduce labor costs and the need for additional structural support. Additionally, they are energy-efficient, and many single-ply roofing systems are highly reflective, helping to reduce cooling costs by reflecting the sun’s heat away from the building.
- Another advantage of single-ply roofing is its durability.
These roofing systems can withstand harsh weather conditions, including high winds, heavy rain, and extreme temperatures. They are also resistant to UV rays and chemicals, making them ideal for industrial and commercial applications. Moreover, they require minimal maintenance, reducing maintenance costs over time.
- Single-ply roofing systems offer design flexibility.
They come in various colors and materials, allowing for greater customization options and enhancing the overall aesthetic of the building. Installing single-ply roofing is relatively easy, reducing the time required for installation and minimizing disruptions to building operations.
Disadvantages of single-ply roofing
- Vulnerable to damage and difficult to repair without replacing the entire section
Single-ply roofing systems are susceptible to punctures, tears, and other types of damage, particularly during installation or maintenance. Once damaged, it can be challenging to repair the single-ply roofing without replacing the entire section, leading to additional costs.
- Shorter lifespan compared to other roofing systems
While single-ply roofing systems are durable, they do not last as long as other roofing systems, such as built-up roofing systems. Typically, single-ply roofing systems last between 10-30 years, depending on the materials’ quality and the maintenance provided.
- Expensive installation costs
While single-ply roofing systems are easy to install, the cost of the materials can be higher than other roofing systems, particularly if the roofing system is customized or if specialized materials are required. This can make the overall installation cost more expensive than other roofing systems.
- Susceptible to wind uplift
Single-ply roofing systems can be vulnerable to wind uplift, particularly in areas with high winds. This can cause the roofing system to peel away from the roof deck, leading to water infiltration and other types of damage. Proper installation and proper fastening techniques can help reduce this risk.
Built up roofing
Built-up roofing (BUR) is a time-tested roofing system used for over a century in the United States. The system consists of alternating layers of oxidized bitumen and bitumen-coated membranes, also known as felts or ply sheets. These ply sheets are reinforced with a high tensile strength fiberglass mat, which gives them dimensional stability and durability. The multiple layers of ply sheets and bitumen create a redundant, multi-ply approach that ensures the system provides reliable waterproofing for many years.
BUR roofs are surfaced with an aggregate or roof coating to enhance the system’s weathering capability. This surface layer also protects from UV rays and other environmental factors. Using an aggregate or coating also adds to the system’s durability, making it capable of withstanding heavy foot traffic and other forms of wear and tear.
Advantages of built-up roofing
- One of the most significant benefits of BUR is its multi-layer protection
The multiple layers of bitumen and felts create a water-resistant barrier that can provide many years of reliable protection from weather elements. Even if the top layer is damaged, the subsequent layers underneath act as a backup to prevent water and weather elements from entering the building. Additionally, the multiple layers create a more rigid and stable surface that can be used as a platform for mechanical systems, solar energy systems, vegetative roofs, or even outdoor living spaces.
- Regarding energy efficiency, BUR multi-ply roofs are known for their excellent thermal performance
The incorporation of roofing insulation into the monolithic roofing membrane results in better insulation or a higher R-value, which can lead to noticeable reductions in heating and cooling costs. BURs can also add a ballast layer, which can further increase their thermal performance. Moreover, BUR systems generally incorporate insulation in their design, and the multiple layers of bitumen and felts can boost the energy efficiency of the system.
- Another advantage of BUR multi-ply roofs is their fire and uplift resistance
BUR systems are tested to meet strict fire resistance requirements and ensure adequate uplift resistance under extreme wind conditions. The continuous adhesion of each layer to one another in BUR systems forms a monolithic structure without the need for fasteners. This monolithic layering reduces the number of penetrations and stress points caused by fasteners and increases wind resistance.
Disadvantages of built-up roofing
While built-up roofing (BUR) systems have many advantages, they are not without disadvantages. Here are some of the most common disadvantages of BUR systems:
- Installation: BUR systems require specialized installation expertise and can be time-consuming and labor-intensive to install properly. Improper installation can lead to leaks and other problems.
- Weight: BUR systems can be heavy, especially if a ballast layer is used. This weight can strain the building’s structure and may require additional reinforcement.
- Maintenance: BUR systems require regular maintenance, like removing debris and inspecting the roof for damage. Repairs can also be difficult to make, especially if the damage is in one of the lower layers of the system.
- Environmental Impact: BUR systems rely on the use of asphalt and petroleum-based products, which have a negative impact on the environment. Additionally, the manufacturing and transportation of these products contribute to greenhouse gas emissions.
- Fire Hazard: BUR systems are susceptible to fire damage and may not meet some building codes in areas prone to wildfires. The use of fire-resistant materials can help mitigate this risk.
Comparing single-ply vs. built-up roofing
In this section, we will explore the key differences when choosing single-ply roofing vs. built-up roofing to help you make an informed decision for your roofing needs.
Single-ply roofing vs. built-up roofing: Installation
One of the most significant differences between single-ply roofing and built-up roofing is the installation process. Single-ply roofing is typically faster and easier to install than built-up roofing, requiring less labor and specialized expertise. In contrast, built-up roofing is more labor-intensive and requires specialized knowledge and experience to install correctly.
Single-ply roofing vs. built-up roofing: Durability
Both single-ply roofing and built-up roofing have their unique strengths. Built-up roofing is known for its multi-ply approach, which creates a redundant, water-resistant barrier that can provide reliable protection from weather elements for many years. On the other hand, single-ply roofing is highly resistant to harsh weather conditions, including UV rays and chemicals.
Single-ply roofing vs. built-up roofing: Maintenance
Maintenance is another key factor to consider when comparing single-ply roofing vs. built-up roofing. Single-ply roofing is relatively low maintenance, requiring minimal upkeep and repairs. On the other hand, built-up roofing requires regular maintenance, like removing debris and inspecting the roof for damage. Repairs can also be challenging, especially if the damage is in one of the lower layers of the system.
Single-ply roofing vs. built-up roofing: Cost
When it comes to cost, both single-ply roofing and built-up roofing have their unique factors that can impact the overall price. Single-ply roofing is typically less expensive to install than built-up roofing, primarily due to the reduced labor costs. However, single-ply roofing may require more frequent repairs and replacements over time, increasing maintenance costs. Built-up roofing, while more expensive to install, can offer a longer lifespan and reduce maintenance costs.
In conclusion, there is no clear winner when comparing single-ply roofing vs. built-up roofing. Both options have their unique advantages and disadvantages, and the best choice for your property will depend on various factors, including your budget, maintenance needs, and climate conditions. Consult our professional roofers to help you decide which roofing system works best for your property and get a quote.