What is a Built-Up Commercial Roof?

Built-up commercial roof (BUR), or tar and gravel roofs, are used for residential and commercial buildings but are highly prevalent in commercial buildings due to their effectiveness. What is a built-up commercial roof, how is it made, what are its pros and cons, and why is it so often used in commercial buildings? Answers to these questions are below.

 Built-up roofs are among the most common roofing installations in shopping plazas and commercial buildings. This guide will provide an overview of built-up roofs, detail their advantages and disadvantages, and explain why Kerrigan Roofing, serving Dayton, OH, and Columbus, OH, is your best option for installation and repair.

What is a Built Commercial Roof?

 A built-up commercial roof is a common term for a roof covering consisting of multiple layers of bitumen(asphalt)—reinforced by surfacing fabrics—built up or assembled on a roof deck to form a finished membrane. The most exposed layer of the roof (usually wearing a coating of gravel or other aggregate material) is constructed to shield the underlying bitumen from exposure to UV rays and weather damage.

Components of a Built-Up Commercial Roof

1. Roof Deck: The structure of the roof, usually concrete, steel, or wood, to hold the building above.

2. Insulation: Provides thermal resistance and helps with energy efficiency.

3. Base Sheet: a layer of the roof deck or an asphalt-saturated material that is laid over the roof deck.

4. Interply Layers: Multiple layers of bitumen and a reinforcing collage of fabrics (typically fiberglass or polyester) are the backbone of strength and rigidity.

5. Cover: A surface layer of gravel, mineral granules, or a metallic coating that protects the roof from UV rays and mechanical damage.

Construction Process

The construction of a built-up commercial roof involves the following steps:

1. Preparation: Cleaning and priming the roof deck.

2. Installation of Base Sheet: The base sheet is mechanically fastened or adhered to the roof deck.

3. Application of Bitumen: Hot or cold bitumen is applied to the base sheet.

4. Adding Reinforcing Fabric: A reinforcing fabric layer is embedded in the bitumen.

5. Retire Primary Layers: Additional bitumen and fabric layers are added until a minimum of 3 to 5 layers are reached.

6. Surfacing: The final layer of gravel or other aggregate is applied.

 The resulting combination of materials represents a robust, durable, and weather-resistant roof that can withstand not only the elements but also feet.

Advantages of Built-Up Commercial Roof

 Built-up commercial roofs are one of the most commonly chosen roofing systems for many buildings due to the numerous advantages they offer. The following are a few of these benefits.

Durability and Longevity

 The most crucial advantage of built-up commercial roofs is their durability. The layers of bitumen and fabric create a tough, flexible membrane that withstands virtually every origin of a building: dust, dirt, wind, rain, and hail. A built-up commercial roof can last 20 to 30 years or more if properly maintained.

Waterproofing

 Waterproofing on a built-up commercial roof lies in the bitumen layers covering the roof. Commercial buildings are typically expensive to construct with valuable interiors, so leaks would damage the building structure or interior, causing a severe loss for a commercial tenant. With a minimum of four layers of urethane, polysiloxane, or butyl rubber covering the roof structure, you could find that should one fail since it is covered by at least two extra layers – redundancy! – you’ll not have a leak.

Fire Resistance

 Built-up roofs are also generally fire-resistant, for they contain fire-retardant chemicals incorporated into the bitumen of the various layers. In fact, the final protective layer of the built-up commercial roof usually consists of gravel or mineral granules. This layer also protects the roof from ultraviolet radiation. They are as fire-resistant as any other type of built-up roof.

UV Protection

 The gravel or reflective sheathing, usually placed as the topmost layer of a built-up commercial roof, protects the layers below it against UV radiation, ensuring that the bitumen doesn’t degrade over the roof’s lifespan.

Thermal Performance

 Manufactured roofs in shops and factories have decent thermal performance because bitumen and the insulation materials trap warm air and prevent too much external heat. If the structure is a factory, this can save substantial energy over the long term.

Disadvantages of Built-Up Commercial Roof

 Despite numerous advantages, built-up commercial roofs also have a few drawbacks.

A built-up commercial roof uses some expensive materials with many advantages, such as ease of maintenance and lifetime warranty. However, it also has some drawbacks. Despite the low cost of materials and lifetime warranties, some drawbacks remain in roofs.

Installation Complexity

 The installation of a built-up commercial roof system takes work and time. It pays to hire the most professional workers and equipment for the job, from lifting heavy felts and paper to making sure all the layers are placed correctly. That can translate to installation costs.

Weight

 The weight can be significant since built-up commercial roofs are often thick, with five or six layers of bitumen and crushed aggregate on a finished roof. Roof systems soon shoulder a substantial portion of the building’s dead load and stress its structure. Here, structural reinforcements may be needed. On other roofs, leaks that are cared for promptly can cause different forms of damage due to mold, rotting wood, and the resulting insect infestation.

Maintenance

 Although modern built-up commercial roof systems are extremely durable, they require periodic inspections, cleaning, and maintenance to keep them in good shape and performing up to the building owner’s expectations—thus avoiding premature roof failure. 

Environmental Impact

 Therefore, bitumen can affect the environment when produced and disposed of. It is made from petroleum, and as a result of the manufacturing process, greenhouse gases are produced. Once the roof has reached the end of its lifespan, it is challenging to recycle built-up roofing because of the toxic components, so it ends up in landfills.

Comparing Built-Up Commercial Roofs to Other Roofing Systems

Here are two standard commercial roofing systems: 1. Built-up (Composition) 2. single-ply

Built-Up Roofs vs. Single-Ply Membranes

 Single-ply membranes (TPO for thermoplastic olefin and EPDM for ethylene propylene diene terpolymer) also gain ground as built-up roof replacements. Here are a few of the key differences:

1. Installation: An SMP can be laid quicker and more efficiently than a built-up roof. It has fewer layers and doesn’t require the same amount of labor-intensive torching on site.

2. Cost: Single-plies typically provide a lower installation cost, but built-up roofs may give a better long-term value from an ROI perspective due to the longevity and lifespan of a roof system.

3. Maintenance: Single-ply membranes require less maintenance but are more prone to punctures and tears. On the other hand, built-up has more strength but needs more excellent maintenance and upkeep.
4. Ingredients: Built-up roofing is the best in waterproofing and UV protection. Single-ply membranes have better thermal performance and are lighter. Performance: Built-up roofing has better resistance and better UV protection. Single-ply membranes have better thermal performance and are lighter.

Built-Up Commercial Roof vs. Modified Bitumen Roof

 Modified bitumen roofing is also very popular and is similar to built-up roofing except for the following differences:

 1) Installation: as modified bitumen roofs may be mechanically fastened but are often torch-applied or self-adhering sheets and relatively easy to install.

2) Layers: Modified bitumen roofs typically have fewer layers than built-up roofs, which leads to shorter installation time and cost.

 3) Durability: Both systems are durable, but built-up roofs may be more resistant to severe weather conditions because they are made up of many layers.

4) Flexibility: Modified bitumen roofs are more flexible, allowing for a better fit on structures with unusual roof shapes or frequent movement.

Why Choose Kerrigan Roofing for Your Built-Up Commercial Roof?

When the time for a commercial roof comes, you must choose the right contractor. Kerrigan Roofing of Dayton & Columbus, OH, offers built-up commercial roofs and serves your commercial roofing needs?

Expertise and Experience

 Kerrigan Roofing works on commercial roofs, where we’ve been installing, maintaining, and repairing built-up roofs for the last twenty years. Our staff brings a wealth of knowledge and experience, and we follow the most current industry standards and best practices.

Quality Materials

 And ensure that only the best materials are used. We guarantee that only the best materials are used for built-up commercial roofs. Our roofs are the best that you can possibly get within your budget. Durable, long-lasting, and weather-resistant are the caveats of making commercial roofs, and we won’t fail you.

Comprehensive Services

 We serve all of your commercial roofing needs with Kerrigan Roofing full-service sheet metal and a dedication to quality. Residential Services: Professional, experienced artistry to help you give your dream home the quality roof it deserves.

Customer Satisfaction

 Our commitment to customer service means we tailor services that best suit customer needs at a competitive price without compromising the quality of our products. We have earned the trust of our clients as the prime roofing contractors in Dayton and Columbus, OH.

Competitive Pricing

 We know how important it is to stay within your price range, and that’s why Kerrigan Roofing is priced competitively. At the same time, we don’t cut corners and provide top-quality roofing service at a great price. We are transparent about our estimates and we work with you to get the best value for your roofing investment.

Warranty and Support

 We offer comprehensive warranties on our built-up commercial roofs because we stand behind the work we do. We are always available when you need us, and we have a support team to answer your questions or concerns.

 Today, when comparing commercial roof systems to single-ply membranes and modified bitumen roof systems, built-up bitumen roofs have clearly demonstrated their superiority in terms of durability and performance. Choosing the right contractor to install your roof is essential to derive the full benefits of your built-up roof system.

 You’ve found Kerrigan Roofing of Dayton and Columbus, OH. Call us today for all your built-up commercial roof projects. We offer quality materials, provide all services and repairs, and fully commit to your satisfaction. Our pricing reflects our quality work, and our warranty and customer support suit the job! 

 Are you considering a built-up commercial roof for your building? Kerrigan Roofing has the answers. Call today to schedule a consultation to determine what can be done to help protect your investment with a quality, durable, and reliable built-up commercial roof.