EPDM Roofing: Everything You Need to Know

Choosing the right roofing system is not easy. There are countless materials and options available, each with its own set of strengths and weaknesses. With so many options, how do you know which will stand the test of time?

At GIDEON Commercial Roofing, we’ve installed millions of square feet of virtually every type of roof system, and we've seen it all. We’ve helped numerous building owners and facilities managers navigate their options and invest in the best roofing system for them.

In this article, we're going to focus on a popular roofing system - EPDM. We’ll give an in-depth understanding of what EPDM roofing is, how it's installed, its advantages, its disadvantages, best applications, and how to maintain it. By the end of this guide, you’ll have a much clearer idea of whether EPDM roofing is the right fit for you.

Table of Contents

• What Is an EPDM Roof?
• Advantages of an EPDM Roof
• Disadvantages of an EPDM Roof
• How an EPDM Roof Is Installed
• Best Applications for EPDM Roofing
• EPDM Roof Maintenance

What is an EPDM Roof?

EPDM, which stands for “Ethylene Propylene Diene Monomer”, is a synthetic rubber roofing membrane. It’s  available in black or white colors and in different thicknesses, typically ranging from 45 to 90 mils. It's most often sold in large, wide rolls that can be used to cover large surfaces with minimal seams, making it particularly well-suited for large commercial or industrial buildings.

Advantages of EPDM Roofing

EPDM roofing has been a popular choice for commercial flat roofs for many decades, and it's not hard to understand why when you consider its numerous advantages:

• Durability and Longevity: EPDM roofing is renowned for its durability and ability to withstand extreme weather conditions. The rubbery material is resistant to UV radiation, temperature fluctuations, and hail impacts. This can make EPDM roofs quite long-lasting, with a lifespan of 20-30 years with proper maintenance.
• Flexibility: One of the standout features of EPDM roofing is its flexibility. The material can expand and contract with changing temperatures, helping it to resist cracking and tearing. This characteristic makes it particularly useful in areas with lots of seasonal variations in temperature.
• Waterproofing: EPDM membranes provide excellent waterproofing capabilities. They are impermeable and can keep your building dry even in heavy rainstorms.
• Ease of Repair: While EPDM roofs are durable, they can still develop leaks or damage over time. However, they are relatively easy to repair. Patches can be applied to the damaged area, and in many cases, this can be a DIY job.
• Cost-Effective: EPDM roofing systems are often more affordable than other types of commercial roofing systems. The material itself is less expensive, and installation is generally quicker and simpler, resulting in lower labor costs.
• Environmentally-Friendly: EPDM is an environmentally-friendly roofing choice. It's designed to be recyclable at the end of its long lifespan, contributing to the circular economy and reducing waste in the construction industry. Its durability and energy efficiency contribute to reduced carbon emissions over time, making it an appealing choice for organizations striving for sustainability.

In fact, in a study using the EPA’s TRACI model, EPDM had a lower global warming potential than other single-ply membranes like TPO or PVC.

Disadvantages of EPDM Roofing

While EPDM roofing has a lot to offer, it also has certain problems that need to be taken into account when making your roofing decision.

• Aesthetics: Unlike some other roofing materials, EPDM is not known for its aesthetic appeal. It usually comes in black or white, and you might find the rubbery appearance unattractive.
• Vulnerability to Punctures: Although EPDM is durable and flexible, it may still be vulnerable to punctures from fallen branches, mechanical equipment, or foot traffic. 
• Seam Failures: Over time, the seams between EPDM sheets can separate and allow water to infiltrate beneath the membrane.
• Installation Sensitivity: EPDM roofing installation is often more susceptible to errors than other types of roofing. It's crucial to hire a knowledgeable contractor because incorrect installation can lead to issues like poor seam bonding and membrane shrinkage.
• Absorption of Heat:Traditional black EPDM roofing can absorb a great deal of heat, making it harder to keep your building cool in the summer. While there is a white (or lighter-colored) option available that can mitigate this problem, it often comes at a higher cost.

How EPDM Roofing Is Installed

There are two primary methods of installation for an EPDM roof:

• Mechanically Fastened EPDM: This is the most common method, where the EPDM membrane is laid out over the roofing insulation and then attached with mechanical fasteners. These fasteners are typically spaced according to the membrane manufacturer’s specifications and local building codes. The edges of the membrane are then sealed using a specialized adhesive.
  
  The advantages of mechanically fastened EPDM include speed and ease of installation. This method also allows for easy inspection and replacement of the membrane if needed.
  
  However, one disadvantage of this method is the potential for billowing in high winds, although this risk can be minimized by proper fastener placement.
• Fully Adhered EPDM: In this installation method, the entire underside of the EPDM membrane is adhered to the insulation or roof deck using an adhesive. The result is a smooth surface that is resistant to billowing and has a higher wind uplift resistance than mechanically fastened systems. It's an excellent choice for high-wind areas and for buildings where aesthetics are a concern. However, it's more labor-intensive and time-consuming to install, so it’s usually more expensive.

There is also the ballasted method, where the EPDM membrane is held down by a layer of gravel or stone, and the induction-welded method, which involves fastening plates underneath the membrane and then bonding the membrane to the plates using an induction welder. These methods are less common and have specific use cases.

Best Applications for EPDM Roofing

For which applications is EPDM roofing best-suited?

• Structures Requiring Lightweight Roofing: Because of its lightweight nature, EPDM is suitable for buildings that cannot support a heavy roof or where additional weight might compromise structural integrity.
• Large Roofs: EPDM roofing can be manufactured in wide sheets (up to 50 feet wide), which makes it a good option for large commercial buildings, as it reduces the number of seams that need to be sealed.
• Buildings in Extreme Climates: The elasticity and durability of EPDM roofing make it suitable for buildings located in areas with extreme weather conditions, be it hot, cold, or fluctuating temperatures. Its resistance to UV radiation, ozone, heat, and cold ensures its longevity despite harsh weather conditions.
• Green Roofs: EPDM is often used as a waterproofing layer beneath green roofs. Its resistance to root penetration makes it an excellent choice for this purpose.

Maintenance of EPDM Roofing

Maintenance is a significant aspect of any roofing system, and EPDM is no exception. Properly maintained EPDM roofs can last over 30 years, delivering excellent value for the investment.

Here are some maintenance considerations for an EPDM roofing system:

• Regular Inspections: Scheduling regular inspections is vital for any roofing system. These check-ups help identify potential issues before they turn into costly repairs. For EPDM roofs, professionals should check for tears, loose seams, and any signs of punctures or blisters.
• Clean the Roof: Keeping the roof free of debris will prolong its lifespan. Accumulated leaves, branches, and other debris can hold moisture against the roof and cause damage over time. Cleaning the roof can be done by sweeping or gently washing the surface.
• Repair Minor Damages Immediately: If the inspection reveals any damage, even minor issues like small tears or loose seams, immediate repair is essential to prevent worsening. Luckily, most minor damages to EPDM roofs can be easily repaired with a patch kit, extending the roof's life.
• Check Drainage Systems: Ensure your roof's drainage system is functioning correctly. Standing water can lead to roof deterioration. Clearing gutters and downspouts and making sure roof drains are unobstructed is a necessary part of maintenance.
• Consider a Professional: While minor repairs and maintenance can be performed independently, hiring a professional for more significant issues or regular inspections can ensure that the job is done correctly and safely.

Remember, the better you maintain your EPDM roof, the longer it will serve your needs, saving you replacement costs and ensuring consistent performance.

The Upshot

With so many choices, choosing a roofing system is no easy task. This is especially true if you're a property manager or owner trying to balance budget, longevity, and maintenance needs. Now that you've learned about the ins and outs of EPDM roofing, set up a call with GIDEON. In a free 30 minute consultation, our nationally-recognized roofing experts can provide you with customized guidance and help you make the right decision for your building.