Featured Article — EPDM Roofing Systems

There are many types of commercial roofing systems each having its own features and benefits. To help our readers become better informed, Jottan will be featuring a different roofing system each month outlining its features and benefits.

Ethylene-propylene diene monomer (EPDM), also known as rubber roofing, is an elastomeric compound that is manufactured from ethylene, propylene and a small amount of diene monomer. According to the EPDM Roofing Association (ERA), within the United States, EPDM accounts for over 1 billion square feet of new roofing annually and represents approximately 35 percent of the entire roofing market.

EPDM is a single-ply waterproof rubber roofing membrane that does not become brittle with age – it will flex and resists changes in temperature without cracking or peeling and has a high resistance to atmospheric pollution.

Other benefits of the EPDM roofing system are:

  • Suitable for flat and slightly pitched roofs
  • Inexpensive and easy to install
  • Provides high quality and leak proof roofs
  • Stretches up to 300 percent and moves with the building through the season
  • Average lifespan of at least 12 to 25 years
  • Requires little maintenance
  • Easily repaired or restored

While EPDM roofing systems require little maintenance, a regular schedule should be set up to check the roof and should only be done by qualified employees or professionals.

For more information on EPDM roofing systems, visit http://jottan.com/projects_applications.php or call Jottan at (800) 364-4234

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The Importance of Well Designed and Wall Installed Roofing Insulation Layer

Considering a new roof? According to an article written by James R. Kirby AIA for roofingcontractors.com, true energy efficiency starts with a well designed and wall installed roofing insulation layer.

A high-quality roof insulation layer should be designed with multiple layers of insulation and with few, if any, thermal bridges. When installed, the insulation board joints should be offset in each direction (so no board-to-board joints align vertically).

For nailable decks (wood and steel), only the first layer of insulation should be attached with fasteners; the remainder should be adhered to the layer below. For non-nailable decks (concrete), all insulation layers should be adhered to the layer below.

Air movement is a very effective way to lose energy. Everyone is familiar with the amount of energy loss from a leaky window. In fact, a few small air leaks can override a high quality insulation layer, whether in a wall or at the roof level. While it’s hard to deny that a roofing membrane is an effective air barrier, it’s also quite important to keep air from migrating across and within the insulation layer. Therefore, it’s critical to eliminate airflow from the roof deck to the membrane. The roof deck is on the interior of the insulation, so it’s “room temperature,” and the membrane is outside the insulation, so it’s the same temperature as the outside. Air moving from the inside to the outside will greatly reduce the effectiveness of the insulation layer, which is why staggering insulation board joints is so critical for energy efficiency.

A metal fastener with a metal washer is a very good means to transfer heat energy across an insulation layer. A metal washer and fastener head just below the roof membrane will transfer heat (and cold) through the shaft of the fastener to the interior of a building. It’s the same reason the building industry doesn’t use metal framed windows anymore. When insulation needs to be fastened to a nailable deck, it’s best to fasten only the bottommost layer, and then all additional layers are adhered. This keeps the washer and fastener head within the insulation layer and therefore much closer to the interior temperature. This design eliminates the thermal bridge from the interior to the exterior.

Also important to know is the International Energy Conservation Code 2012 has very specific requirements for a roof’s insulation layer and for a building’s air barrier. Roof insulation is required to be installed in at least two layers with staggered joints.

The single-layer-of-insulation roof system is quickly becoming a thing of the past, and this will greatly increase buildings’ energy efficiency.