Flat roofing: Tar & Gravel or Modified Bitumen

If you have a home or commercial business with a flat roof, what should you choose for a roofing solution – Tar & Gravel or Modified Bitumen? Most property owners will focus on choosing the option that can last the longest as an excellent investment and withstand the daily challenges of the weather elements.  Let us look at what makes up both roofing systems along with their advantages and disadvantages.

Around for more than a century, Tar and Gravel (also known as BUR – built up roofing) is the most common flat-roofing system. Tar and gravel roofs are made up of laminated layers of asphalt-based sheets, hot tar, and roofing felt. The top layer is covered with gravel which protects the layers against sun damage and reflects some of the sun’s light.  When properly installed, it forms a sealed system from combining multiple waterproofing layers that does not allow water under the roofing system.

The advantages of this tried-and-true roofing system are numerous, especially when installed by a good roofer. It is inexpensive and can last a long time when properly maintained. However many top roofers in the area know this roofing system also has some key disadvantages:

  • A tar and gravel roof can be very heavy, and you may need to strengthen your roof before application.
  • If your building has a flat roof that was originally designed for a BUR roof system, other roofing systems such as Modified Bitumen will not be suitable since they require a ¼ inch or greater slope to prevent ponding water.
  • Strong sun exposure can damage the roofing membrane if it is left uncovered by the gravel reducing its life expectancy.
  • It takes longer to install. Installers need to be experienced and well trained to ensure consistent thickness and coverage.
  • The components are not recyclable – tar, felt and fiberglass.
  • A heavy tar smell when its being installed. It is bad for the installers and the people around it when the roof is being constructed.
  • Leaks in a tar and gravel roof can be very difficult to trace.

A second option to consider is Modified Bitumen which Astro installs on many Daytona Beach, Ormond Beach and Port Orange commercial buildings. Introduced.in the mid-1970s, modified bitumen membranes are roofing sheets made of asphalt that has been modified with either rubber (SBS) or plastic (APP). This gives the sheets more stretch and flexibility. Like tar and gravel roofs, modified bitumen is installed in multiple plies, typically up to 3. Torches or hot-air welders are used to join material seams, creating a watertight system. Astro Roofing services is highly experienced in the safe installation of this material.

The advantages of Modified Bitumen roofing system

  • More uniform. Modified bitumen sheets are manufactured under tight quality control, resulting in a roof with consistent thickness.
  • The modified material can handle temperature extremes better than tar and gravel roofs so it is perfect for Florida.
  • This material is recyclable.
  • No heavy tar smell during installation.
  • Roof leaks are easier to find and repair. Once properly patched, you walk away knowing that its truly found and sealed.

Get a free roofing estimate

If you are considering one of these types of flat roof options, then you need to contact your local roofing expert, ASTRO ROOFING INC., for more details. We bring superior knowledge and installation experience in commercial and residential roofing. We will work with you to understand what type of roofing is right for your home or business and ensure it is the right investment to meet your needs. Contact us today.