Why use EPDM roofing?

commercial flat roof with EPDM

Protecting Your Roof

All across the southern states, from Texas through Mississippi and into Florida, the weather can take a toll on anything and everything. And with its constant exposure to everything from hot blistering sun to high winds and hailstorms, the flat roofing on a commercial structure takes a beating. This is why many commercial structures in this area use EPDM roofing material. 

What does EPDM roofing stand for and what is EPDM roofing? 

EPDM roofing material is an abbreviation for Ethylene Propylene Diene Monomer, a terpolymer synthetic rubber roofing membrane that is widely used on flat or low-slope roofs. Ethylene and propylene are the two primary ingredients, both being derived from oil and natural gas. It is sold in widths measuring between 7.5 feet up to 50 feet and with a thickness of 45mil or 60mil. Known for strengths rather than aesthetics, EPDM roofing typically only comes in black or white. 

Why use EPDM roofing? 

EPDM roofing is a rubber membrane that is known and chosen by building owners for its several benefits, including: 

  • A long lifespan, averaging between 25 years and 30 years. 
  • Flexibility that makes it more durable because it can move with the building
  • Lightweight, making the material easier to install
  • High resistance to hail, UV rays, wind, hail, and more
  • Resistant to extreme temperatures and thermal shock 
  • Watertight when installed by an experienced contractor that knows how to apply EPDM roofing
  • Comes in varying widths, minimizing the number of seams on a roof
  • Reflects heat from penetrating rays, keeping the interior of a building cooler leading to less need for air conditioning and more energy efficiency
  • Almost 100% recyclable

What goes under EPDM roofing?

An experienced roofing contractor that has worked with EPDM roofing before and understands the material will take the following steps prior to installing the EPDM material:

  • A new wood-framed roof will have an exterior-grade plywood or OSB (oriented strand board) sheathing attached using non-popping fasteners. 
  • An existing wood-framed roof will be stripped, with new plywood or OSB installed over the existing sheathing. 
  • If the roof appears to be in good shape after stripping, ring-shank nails will be installed adjacent to the original fasteners, overlapping them to prevent popping of the original.
  • A new concrete roof will be steel troweled and allowed to cure for 30 days before the waterproofing is applied. 
  • An old concrete roof will be stripped, pressure washed, and then patched. 
  • Prior to starting the EPDM roofing job, the contractor will inspect the roof and caulk any edge transitions or large gaps. They will also grind or sand down any protrusions, and round off all external edges to a half-inch radius.

What sizes does EPDM roofing come in?

EPDM roofing membrane comes in widths as small as 7.5 feet and as wide as fifty feet. There are three different thicknesses to choose from: 45 Mil, 60 Mil, and 90 Mil. A Mil is one/thousandth of an inch – for comparison, the 45 Mil thick EPDM roofing membrane is almost equal in thickness to a dime.

Is EPDM roofing flammable?

No. In fact, EPDM roofing is highly fire-resistant, being virtually impossible to ignite and able to impede a fire’s progress. This makes it an incredibly safe roofing material overall.

Which is better – EPDM or TPO?

When you need commercial roofing that needs dimensional stability, TPO roofing is the better choice because EPDM has a higher chance of shrinking, which can lead to leaking and other problems. Other reasons some building owners may find TPO to be the better roofing choice include: 

  • ENERGY EFFICIENCY: TPO has high reflectivity. This can save money for buildings with either electric or gas heat and cooling. Whereas EPDM is generally installed on darker surfaces, TPO is always a light color to help reflect the heat. This is a big bonus for those in southern states. 
  • INSTALLATION CONVENIENCE: TPO is versatile with its installation. It can be adhered, installed mechanically, or welded. 
  • REPAIRS: TPO can be repaired by heat-welding after cleaning the membrane. Repairing EPDM is dependent on the weather. If it is too cold, welding or re-taping requires a primer and adhesives instead, or building owners will need to wait for warmer weather.  
commercial EPDM roofing

A Final Note – How do you repair EPDM rubber roofing?

While we just pointed out that it is much easier to repair TPO roofing, that doesn’t mean EPDM roofing can’t be repaired. For a long-lasting repair to EPDM roofing, as long as you have the proper materials and follow careful preparation, the synthetic rubber that makes up EPDM roofing membrane can be repaired quite easily in fact. 

Do note that you cannot use asphalt-based products like roofing cement flashing or an asphalt-based roof coating. Aluminum roof coating should not be used either, as all of these will contaminate the membrane and lead to a need for further repair. 

The EPDM roofing repair process is as follows: 

  1. Prepare the surface by cleaning off any dirt and oxidation with an all-purpose household cleaner that won’t leave a residue. 
  1. Cut the right size patch – about two inches bigger than the area being patched. 
  1. Prime the area with a thin coat of roofing primer for EPDM roofing material using a paintbrush or a paint roller. Spread the primer beyond the edges where the patch will be placed. 
  1. Install the repair patch with a pressure-sensitive patch by removing the backing and applying it to the roof. You can also use a glue-down type patch with EPDM adhesive to attach it. 
  1. Seal the edges of the patch with an EPDM lap sealant, smooth and flattening the sealant as you work it.

Keeping all this in mind, you can have great EPDM roofing for your building that will last for years to come. Reach out to us if you have any more questions or you’re interested in the installation of this quality roofing material.