You are currently viewing Foam Versus Built Up

Foam Versus Built Up

Commercial Flat Roof Replacement You Can Trust

As a building owner or property manager considering their commercial flat roof choices, a couple of systems you’ll want to scrutinize are spray foam polyurethane roofing (SPF) and built up roofing (BUR).

At Armadillo Roofing & Exteriors, we want to ensure that our commercial customers have all the information they need to make the best possible choice. Here, we’ll compare the advantages and disadvantages of each of these commercial flat roofing systems.

Spray Foam Polyurethane Roofing

SPF is in a liquid form sprayed on top of the existing roof that expands into foam that covers all the nooks and crannies in the existing roof. This type of roofing was introduced in the 1960’s and isn’t the most common type of material chosen. However, that is quickly changing.

Built Up Roofing

For over 100 years, BUR systems have been installed on flat roofs. A phrase often used for these types of roofs is “tar and gravel”. They are applied with layers of tar and asphalt, alternating them, applying the fabrics straight onto the roof. The building owner can choose how many layers will be installed. Lastly, a layer of gravel or stone is installed over it.


Commercial Flat Roof InstallationSPF Commercial Roofing – Before installing an SPF commercial roof, you have to prepare the existing one. You don’t have to strip off the existing material, but all dirt, dust and contaminants will need to be cleaned off of it. The foam is applied first by mixing 2 liquids together and spraying them onto the existing roof. As it’s sprayed on, it expands and forms the solid surface.

Later, an acrylic or silicone coating is applied to reflect heat and protect it from weather elements.

Built Up Commercial Roofing – The first layer of a BUR commercial roof is installed directly onto the roof substrate. For a space that’s safe to complete the install, a base sheet should be attached to the roof first. Then, you start alternating layers of reinforced fabric and bitumen. Depending on your building’s needs and your budget, you can apply up to 5 layers. To protect the system from extreme temperature ranges and wind, a layer of rock or stone is applied on top. This will make the roof more esthetically and architecturally appealing.

Experienced Commercial Flat Roof Replacement Contractors

Comparing Costs

SPF commercial systems will usually cost anywhere between $4 and $7 per sq. ft., making them slightly more economical.

BUR commercial roofing systems will cost from about $5 per sq. ft. and $9 per square ft on the high end. This can vary depending on your choice of materials.


SPF Commercial Roofing – An SPF commercial roof, when installed properly will last as long as 50 years. Here are some of SPF roofing’s other advantages:

  • The barriers it supplies delivers a very high R-value per inch, making it very energy efficient.
  • It can expand and contract with the structure, which means less cracking or splitting, making it extremely durable.
  • No material to dispose of from the old roof, making it environmentally friendly.
  • Its seamless and waterproof due to its sealing all the vulnerable areas of your roof with a continuous, solid surface.

Built Up Commercial Roofing – If a commercial built up roof is correctly installed and maintained over time, it will last as long as 40 years. These are some of the other advantages for BUR commercial roofing systems:

  • They proved UV ray protection by reflecting the sun’s rays.
  • No joints or seams, which makes for a continuous, seamless waterproof system.
  • They require little maintenance after installed.


SPF Commercial Roofing – There are also a few negatives about SPF roofing you need to be aware of:

  • Limited times for installation – cold, windy or rainy weather won’t work for installing SPF systems.
  • Contractor experience – you need a roofing contractor that specializes in this type of application.
  • Overspray – you need to protect cars and personal property around your home as the overspray of the material could damage them.
  • They need more inspections – preferably twice a year.damage them.

Built Up Commercial Roofing – BUR roofs have been around quite a while, but they only last with the proper type of maintenance. Here are some of the disadvantages to BUR:

  • There will be hazardous vapors and fumes while it’s being installed, so safety measures must be taken.
  • Its heavier and adds significant weight to the top of your structure.
  • The time to install is longer – making it more inconvenient.
  • Its installation cost is higher.

Armadillo Roofing & Exteriors (512) 333-7663, provides commercial flat roof repair, commercial flat roof replacement and commercial flat roof installation services to Austin, Texas and the surrounding communities. We have been providing commercial roofing services to the area for over 15 years. When you need advice regarding the flat roof on the building you own or manage, give us a call.

Leave a Reply