Built-Up Roofing: The Three Most Common Issues

built up roofing

Built Up Roofing (BUR) stands as a cornerstone in the world of commercial roofing, renowned for its reliability and durability. 

As a common choice for many buildings, BUR offers a layered approach to roofing, combining multiple layers of bitumen and reinforcing fabrics to create a finished membrane. 

This blog aims to delve into the world of BUR, specifically targeting the common issues that owners and facility managers often encounter. 

Our expertise in roofing, honed through years of hands-on experience and continuous learning, positions us uniquely to provide insightful, practical advice on this topic. 

We understand that maintaining the integrity of a BUR roof is crucial for the safety and functionality of any building. 

Hence, this blog is crafted to shed light on these issues, offering solutions and tips to ensure your BUR roof remains in top condition.

Understanding Built Up Roofing (BUR)

Built Up Roofing (BUR), a time-tested method in the roofing industry, is a multi-layered system. 

It comprises alternating layers of bitumen (asphalt or tar) and reinforcing fabrics, often referred to as roofing felts or ply sheets. 

These layers are then topped with a final coating, typically gravel or a mineral surface, for added protection and durability. 

The installation process begins with the application of a base sheet affixed to the roof deck. 

Successive layers of bitumen and reinforcing fabrics are then applied, with each layer being carefully bonded to create a seamless, watertight membrane. 

The number of layers can vary, typically ranging from three to five, depending on the desired durability and the specific requirements of the building.

While BUR systems offer notable advantages such as excellent waterproofing capabilities, a high degree of thermal resistance, and resistance to foot traffic, they also have certain drawbacks. 

These include a relatively cumbersome installation process, which can be more labor-intensive and time-consuming than modern single-ply roofing systems. 

Additionally, BUR systems require regular maintenance and inspections to ensure their longevity. 

Common Issues with BUR Roofing

Water Leakage

Water leakage is one of the most prevalent issues faced by Built Up Roofing (BUR) systems. 

This problem typically arises due to the breakdown of the membrane layers, often exacerbated by inadequate drainage or damage to the topmost protective layer. 

Factors like ponding water, which occurs when water remains on the roof surface for extended periods, can significantly accelerate the deterioration process, leading to leaks.

Detecting water leakage early is key to preventing extensive damage. 

Routine inspections, particularly after severe weather events, are crucial. 

Look for signs like water stains on ceilings, blistering paint, or mold growth, as these can be indicators of a leak.

Prevention of water leakage in BUR systems primarily involves regular maintenance and timely repairs. 

Ensure that the drainage system is clear of debris and functioning properly. 

Periodic checks for cracks, splits, or other forms of damage on the surface can help catch issues before they lead to leaks. 

In cases where leaks are found, prompt repair is essential to prevent further damage to the roofing system and the underlying structure. 

Employing professional roofing services for regular inspections and maintenance can significantly reduce the risk of water leakage in BUR roofing systems.


Blistering is a common issue in Built Up Roofing (BUR) systems, characterized by the appearance of bubble-like protrusions on the roof surface. 

These blisters form when gas, typically air or moisture vapor, becomes trapped between the layers of the roofing membrane or between the membrane and the substrate. 

This trapped gas expands when heated by the sun, causing the layers of the roofing membrane to separate and form blisters.

The causes of blistering can vary but often include poor installation practices, such as inadequate bonding of the layers or entrapping moisture during the application process. 

Additionally, a lack of proper ventilation can contribute to moisture accumulation and subsequent blistering.

Blistering can significantly impact the integrity of a BUR roof. 

While small, stable blisters may not pose an immediate threat, larger or expanding blisters can lead to breaks in the roof membrane, exposing the underlying layers to more moisture and debris. 

This can accelerate the deterioration of the roof, leading to leaks and reduced overall lifespan.

To prevent blistering, it is crucial to ensure proper installation and adequate ventilation. 

During installation, care should be taken to bond all layers securely and avoid trapping moisture. Regular roof inspections can help detect early signs of blistering. 

For existing blisters, repairs should be carried out by professionals who can assess whether the blisters can be left alone, need to be drained, or if the affected area requires replacement. 

It’s important to address these issues promptly to maintain the roof’s integrity and prolong its service life.

Surface Erosion 

Surface erosion in Built Up Roofing (BUR) refers to the gradual wearing away of the top layer, typically the gravel or mineral surfacing, exposing the underlying bitumen and reinforcing fabrics. 

This erosion is a natural consequence of prolonged exposure to environmental elements such as wind, rain, and UV radiation from the sun. 

Over time, these forces can displace the protective granules or even degrade the bitumen, leading to the thinning of the roof membrane.

The primary causes of surface erosion in BUR include severe weather conditions, mechanical damage (such as foot traffic), and the natural aging process of roofing materials. 

Inadequate initial installation or poor-quality materials can also accelerate erosion.

Signs of surface erosion include visible thinning of the surface layer, loss of granules, and areas where the black bitumen layer has become exposed. 

In advanced stages, this can lead to cracking or blistering of the roof surface.

Regular maintenance is essential to prevent surface erosion. 

This includes:

  1. Conducting routine inspections to check for signs of wear and tear, especially after extreme weather events.
  1. Ensuring that foot traffic on the roof is minimized and, when necessary, using walk pads to distribute weight evenly.
  1. Keeping the roof surface clean of debris, which can trap moisture and exacerbate erosion.
  1. Applying a protective coating or re-surfacing the roof when signs of erosion are evident.

Addressing minor issues promptly can prevent them from escalating into major problems, thereby extending the life of the BUR system.

It’s advisable to have professional roofing contractors conduct periodic inspections and maintenance to ensure optimal performance and longevity of the roof.

Wrapping Up with BUR

In wrapping up, it’s clear that while Built Up Roofing has its merits, it also comes with challenges like water leakage, blistering, and surface erosion. 

Timely maintenance and expert assistance are crucial for managing these issues and ensuring the longevity of a BUR roof.

However, for those exploring more contemporary and efficient roofing solutions, we at IPP offer a range of exceptional coating systems

These systems are designed not only to overcome the limitations of traditional BUR but also to provide enhanced performance, durability, and environmental friendliness. 

Our coatings are crafted using top-quality materials, ensuring superior performance and reliability. 

They offer a seamless, durable, and weather-resistant covering for your building, coupled with significant cost savings over the roof’s lifecycle. 

Moreover, our solutions are tailored to be energy-efficient, contributing to long-term savings in energy costs. 

By opting for one of IPP’s roof coating system, you choose an advanced, sustainable, cost-effective solution for your roofing needs. 

Let IPP guide you to a smarter roofing choice that aligns with modern requirements and sustainability goals.

Learn more today: https://instacoat.com/our-systems/roof-products-and-systems/