Is Spray Foam Roofing as Durable as Tar and Gravel Roofing?

Traditionally, if your home or commercial building had a flat roof, your roofing system used to be a form of built-up roofing (BUR) like tar and gravel. However, in the 1980s, Armstrong Foam Roofing began to offer San Francisco Bay Area residents a revolutionary roofing system created using spray polyurethane foam (SPF) – now commonly known as foam roofing. This new form of roofing consists of a monolithic cellular membrane covering the entire roof, combining insulation and moisture resistance into one material. Even though foam roofing is superior to built-up roofing systems, many homeowners still replace their aging roofing systems with tar and gravel. Unfortunately, they have the misconception that tar and gravel roofing is more durable and affordable than foam roofing.  

What is Tar and Gravel – BUR Roofing?

Tar and gravel roofing has been used to protect homes and commercial buildings with flat roofs for over a century. It is created by installing alternating layers of asphalt/tar along with felt or fiberglass fabrics applied with heat. The number of layers can vary depending on the needs and budget of the home or property owner. The final layer of this roofing system consists of gravel to protect the underlying layers from ultraviolet rays, hail damage, or heavy rains, and extend its lifespan. 

The Lifespan of Tar and Gravel Roofing

The lifespan of tar and gravel roofing is usually around 15 years after which, it needs to be removed and replaced with new layers. The replacement or repair of a tar and gravel roofing system can produce costly tear-offs and waste which will need to be disposed of in landfills and essentially add to our environmental problems.

Problems Related to Tar and Gravel Roofing

One of the main drawbacks of a tar and gravel roof is that it is heavy and flat roof buildings may have to have the envelope (the supports structure) strengthened roof installation. Another problem is that sun exposure can damage the roofing membrane when it is left unprotected by the gravel (gravel can be affected by foot traffic, strong winds, and heavy rains). 

What’s more, tar and gravel roofing has seams that, in time, due to expansion and contraction, start to separate and permit water and microbes to seep in and damage your roof. This roofing also utilizes flashing at the intersection between walls and other roofing features like chimneys, pipes, skylights, or compressors. The flashing is designed to provide waterproofing in these areas but due to expansion and contraction, improper installation, and degradation over time, it loses its integrity and adhesion. Once the flashing begins to peel away, moisture and water can seep into your roofing structure and cause leaks.

What is Foam Roofing or SPF Roofing? 

Unlike tar and gravel roofing, spray foam roofing consists of a monolithic layer of solid closed-cell polyurethane foam that is created by mixing two liquid chemicals together which react to form a solid piece that easily adheres to the roof. The foam density used by Armstrong Foam Roofing is rated at 3LB which means that our roofs have the highest quality roofing foams available today. The 3LB foam used offers high insulation values, strength, and exceptional longevity.

The Lifespan of Foam Roofing

Armstrong’s foam roofing systems can last a lifetime by only having to recoat them approximately every 20 years. Studies conducted by Dr. Dean Kashiwagi, and Dr. Renee Dupuis, between 1983 and 1996, found that the physical properties of foam roofing do not diminish over time. Kashiwagi found that 97.6% of roofs that were over 25 years old did not leak and 93% had less than one percent deterioration! These statistics are even more impressive when we take into consideration that 55% of those roofs were never maintained.

What Makes Foam Roofing More Durable than Tar and Gravel Roofing 

Foam Roofing Protects Your Roof from Leaks

Firstly, since foam roofing has no seams or multiple layers, the issue of expansion and contraction is eliminated. There are no layers separating to allow water and microbes to seep in and damage your roof. It also eliminates roof leaks caused by faulty flashing because foam roofing conforms to any substrate when installed. This makes it ideal for flashing parapet walls, equipment, skylights, and cooling towers.

Foam Roofing Has Strong Adhesion and Durability Properties

The adhesion properties of spray foam roofing add to its strength and durability. This is especially important when we experience severe weather such as hail storms, strong winds, and other conditions that could cause structural damage to a BUR roof. 

Foam roofing or SPF roofing systems provide superior hail impact absorption and protection against strong winds. Furthermore, if a wind-driven missile damages the roof, it will rarely cause a leak and the damage can be easily repaired without compromising performance. In addition, foam roofing provides high wind uplift resistance, proven by field observations of spray foam roofing performance during Hurricanes Allen, Hugo, and Andrew.

Armstrong’s foam roofing systems are durable enough to withstand regular maintenance of HVAC units, compressors, skylights, and whatever other systems may be installed on them. The Spray Polyurethane Foam Alliance (SPFA) states that foam roofs can sustain up to 50 pounds per square inch (PSI) which is strong enough to support the weight of any person. 

Affordability of Foam Roofing

Over the last 40 years, Armstrong Foam Roofing has proven that foam roofing systems are not only more durable than tar and gravel roofing but also more affordable. The initial cost of foam roofing is about the same as BUR roofing with underlying insulation. However, this does not take into account the savings foam roofing has to offer you after its installation.

For example, foam roofing can reduce your heating and cooling system’s energy consumption by up to 40%. Spray Polyurethane Foam is one of the most energy-efficient materials available for flat roofs – it is over 500% more efficient than conventional roofs. This means that the savings in energy costs over a period of 4.5 years can pay for the cost of your foam roof installation.

Choosing the Right Foam Roofing Contractor

Recognizing the value of foam roofing, and the fact it has proven to be more durable and affordable than tar and gravel roofing, foam roofing has become very popular. However, there are few foam roofing contractors in the San Francisco Bay Area who can match Armstrong Foam Roofing in terms of experience and performance. We have more than 40 years of experience in installing foam roofing systems!  We are also proud to claim that we have installed more residential foam roofing than any other company in America. 

You must keep in mind that your foam roofing system will only be as good as the individuals who apply it. Consequently, you should contact professional local contractors with years of proven expertise and a high degree of technical knowledge. 

Only trust the best, that’s why you should contact the experts at Armstrong Foam Roofing. We offer a no-obligation Satellite Roof Estimate and you can also arrange a remote free consultation, either by phone at 1-887-777-1234, via computer, Skype, or by email. Along with all the virtual ways we are providing estimates, we also offer at-home (outside) estimates for your convenience. To find out more about our foam roofing systems and our installation process, contact Armstrong Foam Roofing today.

Back to Media

Real Protection

Flat roofed homes are unique and offer sleek lines, designed with style. However, flat roofs come with their fair share of problems.


Ask your Question

    This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
    Learn more about our Privacy Policy.