In the realm of roofing materials, one option stands tall – quite literally – offering durability, longevity, and reliability: the Built-Up Roof (BUR). A stalwart in the roofing industry for over a century, the Built-Up Roof has cemented its reputation as a dependable choice for both residential and commercial properties. In this comprehensive guide, we’ll delve into everything you need to know about Built-Up Roofs, from their composition to their benefits and installation process.
What is a Built-Up Roof?
Built-Up Roofing, commonly abbreviated as BUR, is a traditional roofing system consisting of multiple layers of bitumen alternated with reinforcing fabrics. These layers create a durable, weather-resistant membrane that is ideal for flat or low-sloped roofs. The construction process involves alternating layers of bitumen – typically asphalt or coal tar – and reinforcing materials like fiberglass or organic felt.
Composition of Built-Up Roofs
Bitumen:
Bitumen serves as the waterproofing agent in Built-Up Roofs. It can be either asphalt or coal tar, with asphalt being more commonly used due to its availability and cost-effectiveness. Asphalt bitumen is derived from crude oil and is heated to become a viscous liquid suitable for roofing applications.
Reinforcing Fabrics:
Reinforcing fabrics, such as fiberglass or organic felt, are embedded within the layers of bitumen to provide strength and stability to the roofing membrane. These fabrics add tensile strength to the roof, enhancing its resistance to tearing and punctures.
Surfacing:
Built-Up Roofs are typically surfaced with aggregate materials like gravel or mineral granules. This surfacing provides additional protection against UV rays, weathering, and mechanical damage. Alternatively, Built-Up Roofs can be coated with reflective coatings to improve energy efficiency and reduce heat absorption.
Benefits of Built-Up Roofs
Durability:
Built-Up Roofs are known for their exceptional durability, capable of withstanding extreme weather conditions, including heavy rain, snow, and hail. The multiple layers of bitumen and reinforcing fabrics create a robust membrane that can endure prolonged exposure to the elements.
Longevity:
When properly installed and maintained, Built-Up Roofs can have a lifespan of 20 to 30 years or more. Regular inspections and timely repairs can further extend the roof’s longevity, providing excellent value for the investment.
Fire Resistance:
The use of bitumen and mineral surfacing makes Built-Up Roofs highly resistant to fire, earning them a Class A fire rating. This fire resistance can enhance the safety of the building and potentially reduce insurance premiums.
Low Maintenance:
Built-Up Roofs require minimal maintenance, making them a hassle-free option for property owners. Routine inspections and occasional repairs are typically all that’s needed to keep the roof in optimal condition.
Installation Process
The installation of a Built-Up Roof involves several steps:
- Substrate Preparation: The roof substrate is cleaned and inspected for any damage or defects.
- Application of Base Sheet: A base sheet, typically made of fiberglass or organic felt, is installed over the substrate and secured with adhesive or fasteners.
- Layering of Bitumen: Bitumen is heated and applied to the base sheet in multiple layers, with reinforcing fabrics sandwiched in between.
- Surfacing: Once the desired number of layers is achieved, the roof is surfaced with aggregate materials or reflective coatings.
- Final Inspection: The completed roof is inspected for quality and integrity to ensure it meets industry standards.
Built-Up Roofs have stood the test of time as a reliable and resilient roofing solution. With their durable construction, longevity, and low maintenance requirements, they remain a popular choice for flat and low-sloped roofs. Whether for residential or commercial applications, Built-Up Roofs offer unparalleled protection and peace of mind for property owners. Consider consulting with a qualified roofing contractor to determine if a Built-Up Roof is the right choice for your next roofing project.