EPDM roofing, or more formally “Ethylene Propylene Diene Monomer” roofing, is a type of single-ply roofing membrane that has remained a popular, time-tested staple of the commercial roofing industry since the 1960’s. EPDM is readily available and relatively straightforward to install, meaning less labor costs than other more complex roofing systems. Thanks to its traditional installation options and easy repairs/maintenance, it’s an economical roof option with lifespans that can exceed 30 years.
EPDM roofing is known colloquially as “rubber roofing,” thanks to its synthetic rubber composition, and comes with a host of cost-effective benefits that make it a top-choice for many commercial building owners. Having originated in the automobile industry and been widely used since, EPDM is considered the most time-tested single-ply membrane roof, sitting behind only TPO roofing in terms of popularity and prevalence.
What is EPDM Roofing?
EPDM roofing, or “rubber roofing,” is a thermoset single-ply membrane roof, meaning the entire roofing system is chemically bonded together with self-bonded adhesive or pressure sensitive seam tape. It's made of a single-sheet of synthetic rubber material that is mechanically fastened, adhered, or ballasted with a river-rock top.
Unlike other single-ply membrane roofs like TPO roofing and PVC roofing, EPDM roofs are not typically reinforced with a polyester scrim, although depending on your building type and usage, the option is available. EPDM roofs have a wide-range of prefabricated accessories making any flashing detail a breeze. Additionally, roofs with a higher volume of equipment are less of an obstacle.
What are an EPDM Roof's Biggest Advantages?
One of EPDM’s greatest strengths is its long documented service life. EPDM roofing technology has 50 years of field testing to support it, making it one of the most reliable commercial roofing systems available.
They are extremely flexible and provide a high level of waterproofing. They also offer a variety of installation options and insulation types, allowing building owners more autonomy and flexibility to determine an ideal roofing system for their timeline and budget.
EPDM roofs are highly weather-resistant and hold up very well to long-term heat aging and UV exposure. They also share the same prefabricated accessories as other single-ply roofing systems, allowing an easier installation with fewer steps to complete the details.
Ballasted EPDM roofs that are well-maintained, regularly inspected, and repaired by certified roofing contractors can last up to 30 years.
How Much Does EPDM Roofing Cost?
Like all roofing types, there are a number of factors that affect the overall cost of an EPDM roof installation, such as access to the roof, how congested the roof is, the number of existing penetrations, and whether a full tear-off of the existing roof type is required.
That said, typically 60 mil-sized EPDM membrane material is priced at roughly $0.55/square foot before labor. Comparatively, TPO roofing is priced around $0.50/sq ft and PVC roofing is around $0.70/sq ft. Like all single-ply roofing systems, EPDM benefits from being easy to install, repair, and maintain.
What Other Factors Affect the Cost of an EPDM Roof?
Labor is the biggest price determinate for roof replacement projects of any scale. The amount of required laborers, equipment, and time are all affected by the condition of the existing roof environment and how difficult it is to access. If a roof demands specialized equipment to safely access, additional equipment rentals and increased mobilization will have a noticeable effect on the overall cost.
One unique EPDM cost consideration is that a scrim reinforcement seen in other single-ply roofing membranes are traditionally not included EPDM roofing installations. While including a scrim in the installation would create an additional up-front cost, that additional layer of protection could save you repair costs and headaches down the line. Without any reinforcement, EPDM’s single-ply system is susceptible to more punctures and penetrations than other commercial roofing systems.
Because EPDM roofing material is normally composed of black rubber, another unique cost consideration is more costly white EPDM. Whereas black EPDM material costs around $0.55/sq foot, white EPDM is nearly twice that at around $0.90 - $1.00/sq ft. White EPDM, like other single-ply roofing systems composed of white materials, offers reflectivity and saves significant energy costs over time, especially if your building is prone to more hot-weather days.
How Are EPDM Roofs Installed?
EPDM roofing’s most common installation method is ballasted, however they can also be mechanically fastened or adhered. Ballasted EPDM roofs are held in place by large round stones or slabs, known as “river rock.”
Mechanically fastened EPDM roofs are screwed through the seams down to the structural deck with special plates and fasteners. This is considered a more cost-effective installation option, but there’s a catch: because of this method’s lack of wind uplift performance, your roof is more vulnerable to heavy wind damage, so mechanically fastened installations are not recommended for buildings exposed to stronger wind conditions.
Adhered roofs are chemically glued to maintain a smooth, flat surface and offer higher wind uplift performance, as well as a more aesthetically pleasing appearance.
EPDM roof rolls can also arrive with pre-applied seam tape for self-adherence, making them relatively simple to install. It’s worth noting, however, that self-adhered EPDM is generally not as integrally sound as other adhered installation types.
How Are EPDM Roofs Repaired?
Like other single-ply membrane roofing systems, EPDM is relatively easy and less costly to repair.
EPDM roofing repairs involve the cleaning and priming of its membrane, installation of self-adhered flashing, and an exterior lap sealant to ensure it’s fully waterproofed. While the process sounds relatively straightforward, these repairs often require special equipment and experienced roofers, so only trust a certified roofing professional should conduct these repairs before attempting yourself or hiring a “Pete and a truck” contractor.
What Are an EPDM Roof's Insulation Types?
EPDM shares a number of its qualities and advantages with TPO roofing roofing systems, such as their suite of prefabricated accessories and insulation types.
EPDM has 3 major types of insulation with various different determinants and R-values. An R-Value measures a material’s ability to resist thermal movement, so the more “insulating” the material is, the more effective it is at retaining heat, and the higher its R-value will be.
Polyisocyanurate, or polyiso, is the most popular insulation thanks to its high R-value per inch of insulation. Polyiso is usually a great fit for EPDM roofs, but because of its flammability, it may not be suitable for buildings with certain fire restrictions or combustible deck types such as wood (ex. Class A).
Expanded Polystyrene, or EPS, is more cost-effective and offers a higher R-value per dollar but is normally only recommended for tapered roofing systems.
Extruded Polystyrene, or XPS, is known for its blue, green, or pink colors. Its price to R-value ratio falls in the middle between polyiso and EPS.
Does EPDM Suite All Building Types?
Whether or not EPDM is suitable for your building is dependent on your building’s use and the amount of congestion or foot traffic your roof endures on a regular basis.
In traditional installations, EPDM roofing systems don’t include a layer of reinforcement, meaning its puncture resistance isn’t as strong as other building types. Similarly, EPDM roofs are discouraged for buildings with a lot of foot traffic. They don't have an excellent chemical resistance either, so it’s a bad choice for restaurants where animal fats or grease can pile up and cause deterioration.
Do EPDM Roofs Have Any Disadvantages?
Compared to other single-ply roofing systems, EPDM roofs require more steps to install, which will increase labor costs to some degree. EPDM requires cleaning, priming, and taping to adhere its seams, as opposed to TPO roofing roofing or PVC roofing roofing which simply needs to be cleaned and heat welded.
Basic EPDM installations don’t include reinforced scrims, meaning lower puncture resistance and more prone to weather or accidental damage. Of course, reinforced EPDM is an option however it does come with additional material cost.
EPDM roofs also require more seam maintenance. Because of their chemically bonded natures, the seams will eventually become unadhered and will need to be repaired.
EPDM roofs are a trusted, time-tested, cost-effective piece of proven roofing technology. Thanks to their relatively easy installation, lower maintenance costs, energy efficiency, lower material costs, weather resistance, and impressive endurance (with proper care), it certainly has earned its place as one of the most common commercial roofing systems available.
If you’re ready to hear more about EPDM or learn whether it’s the right roofing system for your building type, send us your details and we’ll get to work right away.