Built-up roofing systems, also known as tar and gravel roofs, are popular for flat roofs. They consist of alternating layers of fiberglass, roofing felt, and asphalt, creating a durable and long-lasting system. Gravel embedded in the roof protects against severe rain, hail, and UV rays. Factors like climate, building construction, and underlying strata influence the type and weight of gravel used. Tar and gravel roofs offer significant advantages, including a lifespan of up to 25 years due to their weather-resistant properties. Discover more about the benefits of gravel on flat roofs and why this roofing choice might be ideal for you. Keep reading to learn more.
Why Do People Fill Flat Roofs With Rocks Or Gravel?
Flat roofs are commonly used on commercial buildings and often feature gravel on top. Gravel serves two main purposes. First, it protects the roofing materials from damage due to weather conditions. Second, it helps secure the roofing materials in place, preventing them from shifting. This layer of gravel enhances the roof’s durability and stability. By covering flat roofs with gravel, you ensure that the roofing materials remain intact and perform effectively over time. This simple yet effective solution contributes to the overall safety and longevity of commercial roofing systems.
To Safeguard Constructed Roofs
Built-up roofs, commonly known as tar and gravel roofs, are primarily used for flat roofing systems. These roofs are designed for durability, using layers of hot-applied asphalt and roofing felt. The gravel serves to protect the roof from various elements, including small stones, hail, and UV radiation. By applying gravel to the asphalt coat, it ensures that the roofing layers are securely held in place. This approach provides a robust and long-lasting roofing solution that withstands harsh conditions and maintains its integrity over time.
Built-up roofs feature a weatherproofing layer of gravel that significantly extends the life of the roofing surface. This gravel layer prevents deterioration, blistering, and cracking, which can lead to leaks or roof failure. While asphalt provides essential waterproofing, the gravel top layer further strengthens the roofing system. It adds an extra level of protection against the elements and enhances overall durability. By incorporating gravel, the roof remains resilient and maintains its integrity over time, ensuring long-term performance and reliability.
Gravel On Flat Roofs
Ballasted roofs are popular for several reasons, with gravel providing significant benefits. The weight of the gravel holds roofing materials securely to the decking, reducing the need for fasteners. This ballast also helps keep the roofing system cool and protects it from sun damage. Additionally, it can lower energy costs by improving insulation. While a ballasted roof offers many advantages, it’s crucial to be aware of its drawbacks. The amount of gravel applied must be carefully measured to ensure optimal performance.
The amount of gravel added to a roofing system depends on the specific requirements and type of structure. Excessive gravel weight can compromise the building’s structural integrity. Ideally, gravel should weigh between 10 to 25 pounds per square foot. One drawback of ballasted roofs is the difficulty in detecting leaks. Once a leak is found, repairing it can also be challenging. Proper gravel application is crucial for maintaining roof performance while avoiding potential issues with the building’s stability and repair processes.
Benefits Of Bur Flat Roof Gravel In Addition
Gravel on built-up roofing (BUR) flat roofs offers several benefits. It enhances water evaporation and prevents heat buildup in the underlying structure. Additionally, gravel provides a stable surface for foot traffic, which is crucial during roof repairs or maintenance. This added traction helps ensure safety and efficiency when working on the roof. By improving water management and supporting maintenance activities, gravel contributes to the overall functionality and longevity of BUR flat roofs.
Gravel serves as a barrier, preventing natural debris like leaves from clogging roof surfaces. Modified bitumen roofs, made from rubber and asphalt, use gravel to enhance UV protection. This gravel layer shields the roofing system from harmful UV rays, extending its lifespan. By keeping debris away and providing UV resistance, gravel improves the overall performance and durability of modified bitumen roofs.
Ballast Roof System With Gravel
Another type of gravel roofing system is ballast, mainly used with single-ply roofing systems. Its primary role is to reduce the weight of the roofing material while offering protection. This system often replaces traditional tar and gravel with materials like thermoplastic polyolefin, polyvinyl chloride, and propylene diene monomer. Ballast provides an effective way to secure and stabilize single-ply roofs. It combines weight reduction with enhanced durability, making it a popular choice in modern roofing applications.
Single-ply roofing materials are neither bonded nor self-adhering. Ballast plays a crucial role in providing the necessary weight to keep the roof secure during severe storms or high winds. By adding ballast, the roofing system gains stability and resistance against strong weather conditions. This helps ensure that the single-ply roof remains firmly in place, protecting the building from potential damage. Using ballast effectively enhances the roof’s durability and performance, especially in challenging weather scenarios.
Additional Advantages Of Ballast For Flat Roofs
Ballasted roofs not only provide protection but also help absorb heat, enhancing energy efficiency. Single-ply roofs offer sun protection, but the added ballast improves UV resistance. Ballast stones are loose-laid, making them easy to repair or maintain. To repair seams or split joints, apply cement under the open seam and press it down for proper adhesion. For blisters, cut them open with a knife, let them dry, and then cover with asphalt. This approach ensures effective repair and maintenance, extending the lifespan and performance of ballasted roofing systems.
Cracks in asphalt are easy to repair by clearing debris and gravel, then applying a layer of cement. Gravel in ballast roofs enhances heat absorption by preventing the sun from overheating the roofing materials, thus improving energy efficiency. The ballast also protects against hail and foot traffic, especially during repairs and maintenance. This system is cost-effective, easy to install, and energy-saving—key features that make it a popular choice for roofing. By incorporating ballast, you ensure a more durable and efficient roofing solution that meets various practical needs.
Conclusion:
Gravel plays a crucial role in flat roofing systems, enhancing both durability and performance. Built-up roofs, or tar and gravel roofs, use gravel to protect against severe weather, UV rays, and physical damage. This gravel layer supports the roofing materials, keeping them in place and extending the roof’s lifespan up to 25 years. For ballasted roofs, gravel helps stabilize single-ply systems by adding weight and providing protection from harsh conditions. It also improves energy efficiency by absorbing heat and offers ease of maintenance. Overall, gravel in roofing systems delivers significant benefits, from structural stability to enhanced energy performance, making it a valuable roofing solution.
FAQs:
- What are the primary benefits of using gravel on flat roofs?
Gravel provides multiple advantages, including enhanced protection against severe weather, UV rays, and physical damage. It stabilizes roofing materials, improves energy efficiency by preventing heat buildup, and offers added traction for safe maintenance. Gravel also acts as a barrier to prevent debris from clogging the roof. - How does gravel help with energy efficiency on flat roofs?
Gravel improves energy efficiency by reflecting UV rays and reducing heat absorption. This helps keep the roofing materials and the building below cooler, leading to lower energy costs for cooling.
- Does gravel on flat roofs help with roof maintenance?
Yes, gravel provides a stable surface that facilitates easier and safer access for maintenance and repairs. It reduces the risk of slipping and damage during routine upkeep.
- Can \gravel on flat roofs prevent leaks?
While gravel itself doesn’t prevent leaks, it protects the underlying roofing materials from damage that can lead to leaks. It shields the roof from harsh weather conditions and physical impacts, which helps maintain the integrity of the roofing system.
- Are there any drawbacks to using gravel on flat roofs?
One potential drawback is that gravel can make it difficult to detect and repair leaks. Additionally, the weight of the gravel must be carefully managed to avoid compromising the building’s structural integrity. Proper installation and maintenance are crucial to address these challenges.
