Built-up roofing (BUR) systems are among the oldest and most reliable types of roofing solutions available for commercial and residential properties. Comprising multiple layers of bitumen and reinforcing fabrics, these roofing systems offer unparalleled durability. This article delves into the core attributes that define the resilience and steadfast performance of built-up roofing solutions.


Historical Robustness

BUR systems have a long history, dating back over 100 years, which is indicative of their reliability and durability. This extensive track record offers property owners peace of mind, knowing that this roofing solution has withstood the test of time.


Multi-Layer Protection

The structure of a built-up roof is its primary defense mechanism: – Base Layer: Serves as an initial waterproof barrier. – Fabric Reinforcement Layers: Multiple plies of fabrics such as fiberglass or polyester are added for strength. – Bitumen: Asphalt or coal tar pitch is alternated with the reinforcement layers to create a watertight membrane. – Top Layer: Typically consists of gravel or mineral granules, offering additional protection against UV rays, weathering, and mechanical damage.

This multi-layer construction not only ensures exceptional waterproofing but also contributes to the roof’s longevity by protecting against various physical and environmental stressors.


Thermal Performance

Built-up roofs possess inherent thermal mass due to their dense nature. This characteristic helps in moderating indoor temperatures by reducing heating during summer months and retaining warmth in colder periods. Consequently, BUR systems can contribute to lower energy costs over time.


Maintenance Ease

While no roofing system is entirely maintenance-free, BUR has an advantage due to its multi-layer structure: – Regular inspections can identify potential issues before they become significant problems. – Repairs are usually straightforward since damages are often confined to the top layer(s), allowing for localized fixes without needing a complete roof overhaul.


Versatility in Application

Built-up roofing can be applied on a variety of roof decks whether flat or with a slight incline. Its adaptability makes it suitable for many kinds of buildings, from commercial warehouses to residential homes with flat roof spaces.


Fire Resistance

Due to the materials used in their construction, built-up roofs generally offer superior fire resistance compared to other roofing options. The gravel or mineral surface layer significantly reduces fire risk by acting as a barrier against sparks and embers.

In summary, built-up roofing stands out for its proven durability and reliability through decades of use across various climates and settings. Its layered composition not only ensures robust protection against water ingress but also provides thermal benefits, ease of maintenance, versatility in application, and enhanced fire resistance. These characteristics make BUR systems an enduring choice for property owners seeking a dependable roofing solution.


Understanding the Differences: Gravel vs. Smooth Surface Built-Up Roofs

Built-up roofing (BUR) systems have been a reliable roofing solution for over a century, offering durable protection for various types of structures. Among the options available within the BUR category, gravel and smooth surface roofs stand out due to their unique characteristics and benefits. This section delves into the differences between gravel and smooth surface built-up roofs, providing property owners with essential information to make an informed decision.


Gravel Surface Built-Up Roofs

Gravel surface BURs incorporate layers of roofing felt impregnated with asphalt, which is then covered with a layer of gravel. The gravel serves multiple purposes:

  • Protection from UV Rays: The gravel layer effectively protects the underlying bitumen from damaging UV radiation, significantly extending the roof’s life.
  • Fire Resistance: Gravel is non-combustible, enhancing the fire resistance of the roofing system.
  • Improved Durability: The added layer of gravel provides extra weight, which helps stabilize the roof against wind uplift and other environmental factors.


Key Characteristics:

  • Weight: Heavier due to additional gravel layer
  • Appearance: Offers a rough texture; color depends on gravel choice
  • Maintenance: May require periodic raking or addition of more gravel


Smooth Surface Built-Up Roofs

In contrast, smooth surface BURs lack the gravel layer and are finished with a coating that is usually made of hot-applied asphalt or a cold application such as aluminum or elastomeric coatings. These coatings also protect against UV rays but in a different manner than gravel.

  • Reflectivity: Certain coatings can reflect sunlight and heat away from the building, contributing to energy efficiency.
  • Flexibility in Aesthetics: Without the granular texture, these roofs can offer a sleeker look and more options for aesthetic customization through different coating colors.
  • Weight: Typically lighter than their gravel counterparts as they do not include the heavy layer of stone.


Key Characteristics:

  • Weight: Lighter without the need for extra structural support
  • Appearance: Smoother finish; can be customized with different coatings
  • Maintenance: Requires regular inspection and re-coating to maintain its reflective properties and UV protection


Choosing Between Gravel and Smooth Surface BURs

The choice between these two types of built-up roofs primarily depends on specific needs such as climate considerations, aesthetic preferences, building structure, and budget constraints. Gravel surfaces are ideal for areas prone to high winds or where additional fire resistance is necessary. In contrast, smooth surfaces might be preferable in urban settings where aesthetic considerations are paramount or in climates where cool roofing is beneficial.

Understanding these differences equips property owners with the knowledge needed to navigate their roofing options effectively, ensuring that they select a BUR system that aligns with their property’s requirements and their long-term objectives for durability, maintenance, and aesthetics.


Unveiling the Key Advantages of Installing a Built-Up Roof on Your Property

Built-Up Roofing (BUR) systems have been a reliable roofing solution for over a century, primarily due to their numerous advantages. These multi-layered roofs are known for their remarkable durability and protective capabilities. Below are the key advantages of installing a built-up roof on your property:


Multilayer Protection

  • Enhanced Durability: The multiple layers of bitumen and reinforcing fabrics offer exceptional durability, making BUR systems resistant to foot traffic, mechanical damage, and severe weather conditions.
  • Waterproofing: Each layer of a BUR system acts as an added barrier against water infiltration, ensuring superior waterproofing qualities that protect the building from leaks and water damage.



  • Extended Lifespan: When properly installed and maintained, built-up roofs can last up to 20-30 years or more. Their longevity is a testament to their robustness and ability to withstand environmental factors over time.


Energy Efficiency

  • Insulation Properties: The thickness and materials used in BUR systems provide excellent insulation. This helps in maintaining indoor temperature levels, resulting in lower heating and cooling costs.
  • Reflective Coatings Optional: For smooth-surfaced built-up roofs, reflective coatings can be applied to further enhance energy efficiency by deflecting UV rays and reducing heat absorption.


Fire Resistance

  • Inherent Fire-Retardant Qualities: The gravel or special coatings used on the surface of built-up roofs contribute to their fire-resistant capabilities, offering an added layer of protection for the property.



  • Adaptability: BUR systems can be customized to fit various roof shapes, sizes, and inclines without compromising performance. This makes them suitable for a wide range of buildings.
  • Design Options: Though traditionally finished with gravel or slag toppings, modern advancements allow for smooth surfaces or even garden roofing setups atop built-up systems.



Multilayer Protection

Offers enhanced durability and superior waterproofing through its layered construction.


Capable of lasting 20-30 years with proper maintenance due to its robust nature.

Energy Efficiency

Provides significant insulation properties; reflective coatings can be added for extra efficiency.

Fire Resistance

Features inherent fire-retardant qualities through its materials and possible surface treatments.


Adaptable to various architectural needs; offers different design options including green roofing.

The installation of a built-up roof on your property promises not only immediate protective benefits but also long-term savings in maintenance and energy costs. Given these advantages, it’s clear why BUR systems continue to be a preferred choice for both commercial and residential buildings seeking durability without compromising on performance or aesthetics.


Navigating the Challenges: Weighing the Disadvantages of Built-Up Roofing Systems

Built-up roofing (BUR) systems have been a popular choice for flat or low-slope roofs for over a century, offering remarkable durability and water resistance. However, like any roofing solution, they come with their own set of challenges. Understanding these drawbacks is essential for property owners to make informed decisions that align with their building’s needs and long-term maintenance capabilities.


Cost Considerations

  • Initial Investment: The upfront cost of installing a built-up roof can be higher than other roofing options due to the labor-intensive process and materials required.
  • Maintenance Expenses: Over time, BUR systems may require more maintenance compared to single-ply membranes, potentially increasing long-term costs.


Installation Complexities

  • Time-Consuming Installation: The installation process for built-up roofs is lengthier than modern single-ply roofing systems. This can lead to longer project times and increased labor costs.
  • Weight Concerns: BUR systems are heavier due to the multiple layers and gravel surfacing. Structures must be evaluated for their ability to support this additional weight without compromising integrity.


Health and Safety Risks

  • Fumes and Odors: During installation, built-up roofs emit fumes from the asphalt or tar used in the process. These emissions can be unpleasant and pose health risks, requiring proper ventilation and precautions.
  • Fire Hazard: The application process involves heated materials which could increase fire risk during installation.


Performance Limitations

  • Less Flexibility: BUR systems may not perform as well under building movement or extreme temperature fluctuations compared to more flexible materials like EPDM or TPO.
  • Vulnerability to Water Pooling: If not properly installed with adequate slope, built-up roofs can be prone to water pooling, leading to accelerated wear and potential leaks.


Environmental Considerations

  • Energy Efficiency: Traditional BUR systems without reflective coatings absorb more heat, potentially increasing cooling costs. Modern options include cool roofing treatments but may come at an additional cost.
  • Sustainability Concerns: The manufacturing process of traditional BUR materials has a higher environmental impact compared to some newer eco-friendly alternatives.

Despite these challenges, it’s important to remember that no roofing system is without its drawbacks. The key is weighing these disadvantages against the advantages specific to built-up roofing—such as its proven longevity, robustness against leaks, and unparalleled resistance against UV rays—to determine if it’s the right choice for your property. Consulting with a professional roofer who has experience in both traditional and modern roofing solutions can provide valuable insights tailored to your unique situation.


Comprehensive Insights into Modified Bitumen Roofing: An Essential Guide for Property Owners

Modified bitumen roofing systems represent a modern evolution in roofing technology, combining traditional and contemporary roofing techniques to offer enhanced durability, flexibility, and resistance to extreme weather conditions. This guide aims to provide property owners with a thorough understanding of modified bitumen roofing, its composition, benefits, application methods, and maintenance requirements.


Composition of Modified Bitumen Roofing

Modified bitumen (MB) roofing is primarily derived from asphalt and reinforced with either polyester or fiberglass. The modification of asphalt with synthetic rubber or plastic polymers enhances its performance characteristics. This type of roofing typically comes in rolls that are applied on the roof surface to form a watertight membrane. The core components include:

  • Base Sheets or Insulation Layers: These are installed over the roof deck for added insulation and stability.
  • Modified Bitumen Membranes: These layers are composed of modified asphalt mixed with rubber or plastic polymers.
  • Surfacing Materials: To protect against UV rays and physical damage, surfacing materials such as mineral granules or metal films may be used.


Benefits of Modified Bitumen Roofing

Property owners can enjoy numerous benefits from installing a modified bitumen roof:

  • Durability: MB roofs are highly durable, with an expected lifespan of 20 years or more when properly maintained.
  • Flexibility: The polymer modification adds significant flexibility at low temperatures, reducing the risk of cracking.
  • Easy Repairs: Sections can be patched or replaced easily without needing to overhaul the entire roof.
  • Energy Efficiency: Light-colored surfacing options can reflect sunlight and reduce cooling costs.
  • Water Resistance: Properly installed MB roofs offer excellent resistance to water penetration.


Application Methods

There are several application methods available for MB roofing systems:

  1. Hot-Applied: Hot mopping of asphalt is used to adhere the layers together.
  2. Cold-Applied Adhesives: This safer alternative involves using solvent-based adhesives without the need for open flames.
  3. Self-Adhered Membranes: These membranes come with pre-applied adhesive layers that bond upon contact without additional adhesives.
  4. Torch-Applied: Heat is used to melt the asphalt underside of the membrane, creating a bond to the layer beneath.


Maintenance Requirements

While MB roofs are relatively low maintenance, regular checks are essential to prolong their lifespan:

  • Regular inspections should be conducted at least twice a year and after major storms.
  • Keep the roof clear of debris and pooled water that could lead to damage over time.
  • Look out for signs of wear and tear such as cracks or blisters in the membrane.



Modified bitumen roofing offers an effective solution for property owners seeking a blend of traditional robustness and modern technological advances in their roofing system. Its versatility in application methods and significant benefits such as durability, energy efficiency, and ease of repair make it an appealing choice for commercial and residential properties alike. By understanding its composition, benefits, installation approaches, and maintenance needs, property owners can make informed decisions on whether modified bitumen is the right choice for their building’s roofing requirements.


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