Almost all commercial roofs are flat or low-sloped, and as preferences have changed over time, homeowners are also considering flat roofs for their residential properties. With all this, there is one term that has gained quite a lot of attention, roof membranes.
Roofing membranes are a type of roof cover that is specifically made for flat roofs and comes in a variety of different types. Membrane roofs play a crucial role in protecting buildings from the harsh elements, and choosing the right one will ensure a durable and long-lasting roofing system.
In this article, we will explore the pros and cons of each type of roofing membrane, helping you to make a decision that fulfills all your flat roofing needs.
What Is A Roofing Membrane?
A roofing membrane is a critical component of a roofing system that acts as a waterproof barrier, protecting the building’s interior from the elements. It is a continuous sheet or layer of material that covers the entire surface of the roof, preventing water, moisture, and other environmental factors from seeping through and causing damage.
The term “membrane” is used because this layer is thin and flexible, yet strong and durable enough to withstand harsh outdoor conditions.
While membrane roofs may vary in material composition and installation method, their primary function remains the same, which is to provide a reliable and long-lasting waterproof barrier that protects the building and its occupants from the elements.
Single-Ply Membranes
Single-ply membranes are a popular type of roofing system that utilizes a single, continuous layer of membrane material as the primary waterproofing component.
These membranes are typically manufactured from synthetic materials such as thermoplastic polyolefin (TPO), polyvinyl chloride (PVC), or ethylene propylene diene monomer (EPDM).
Let’s take a closer look at each of these materials:
1. TPO Roofs
TPO membranes are a relatively new, but quite popular, choice for low-slope roof replacements in both residential and commercial settings. TPO is a blend of polypropylene and ethylene-propylene rubber, creating a single-ply membrane that offers excellent weatherability.
TPO membranes will also be available in various colors, from traditional white to more modern shades, providing choice in terms of appearance.
Pros
- TPO membranes are highly resistant to ozone, UV rays, and heat, making them suitable for hot and sunny climates.
- They are environmentally friendly, as TPO membranes are typically made from recycled materials and are recyclable themselves after use.
- TPO membranes are highly flexible, allowing for easier installation and better resistance to thermal expansion and contraction.
Cons
- TPO roof membranes are relatively new in the roofing industry, and therefore, their longevity is not as established as other materials.
- TPO membranes have a shorter lifespan compared to some other types of membranes, typically lasting only 15 to 20 years.
- In extremely cold climates, they may become brittle and prone to cracking, requiring extra precautions during installation and maintenance.
2. PVC Roofs
Polyvinyl chloride (PVC) membranes will also be a popular choice for low-slope roofs in both residential and commercial settings. PVC is a synthetic plastic polymer that, when reinforced with additional compounds, creates a highly durable and long-lasting roofing membrane.
Pros
- PVC membranes are highly resistant to chemicals, making them suitable for industrial or commercial environments.
- This flat roofing system is amongst the best when it comes to fire resistance, providing added safety for buildings.
- PVC roofing will be highly durable and have a longer lifespan compared to TPO membranes, typically lasting 20 to 30 years.
Cons
- One of the biggest limitations of an otherwise possible roofing option is its high cost. PVC roofs are more expensive than the other single-ply membranes.
- They’re more susceptible to punctures or tears from falling debris or foot traffic, requiring careful handling and maintenance.
- PVC membranes will be less flexible than TPO membranes, which makes installation more challenging, especially in colder temperatures.
3. EPDM Roofing Membranes
Ethylene propylene diene monomer, commonly known as EPDM, is a popular choice for low-slope roofing applications in both residential and commercial buildings. EPDM roofing membranes are also referred to as rubber roofing or EPDM roof coverings and consist of a single-ply synthetic rubber material that offers exceptional durability and weather resistance.
Pros
- EPDM roofing membranes have the most impressive lifespan compared to other flat or commercial roofing options. EPDM roofs last for 30 to 40 years easily.
- This roof is also quite affordable.
- EPDM rubber roofs are lightweight and easy to install, reducing labor costs.
- These roofing systems are highly resistant to tears, punctures, and wind uplift, providing reliable protection against the elements.
Cons
- EPDM roofs will not offer you versatility in terms of installation and color, as it’s only widely available in black or white
- In colder climates, EPDM membranes become brittle and prone to cracking, even shrinkage.
- The black color of an EPDM roof can lead to higher cooling costs in hot climates, as it absorbs more heat than lighter-colored options.
Also Read: TPO vs EPDM Roofing Membrane: A Comparison Guide
Two-Ply/Three-Ply Roofing Membranes
In the last section, we covered the types of single-ply membrane roofing systems. They are the new age option that offers durability despite being lightweight. However, there are other options that involve the use of two or more layers of membrane material.
A. Modified Bitumen Membranes
Modified bitumen membranes are a popular choice for both low-slope and steep-slope roofs. These roofing membranes consist of layers of asphalt or bitumen, modified with polymers. It has two layers: the base sheet and the cap sheet, with the most popular options being atactic polypropylene (APP) or styrene-butadiene-styrene (SBS). Both act as chemical compounds that enhance the material’s flexibility and durability.
Pros
- Modified bitumen membranes are very durable. These show excellent resistance to weathering and cold temperatures, which is great in chilly areas such as Wisconsin. They are also fire-resistant and UV-resistant too.
- There are no seams on modified bitumen roofs, therefore, your roof will have enhanced resistance to leaks. Multiple layers allow it to fare well against foot traffic too.
- Modified bitumen roofing systems can be installed in multiple ways; either by a heat, or cold application.
Cons
- Though they do not develop leaks as often, they will be susceptible to ponding water So you need to be careful when it comes to maintenance.
- Modified bitumen membranes have a shorter lifespan compared to some other types of membranes, typically lasting 10 to 20 years.
- The top layer of a modified bitumen roofing system is made from asphalt or bitumen and is black. This does not provide good reflectivity and instead, absorbs heat from the sun, increasing your roof’s temperature.
4-Ply Roofing Membranes
Last but not least, we cover the roofing membranes that are made with 4, or even 5 layers of materials. This layered method of construction creates a highly durable and weather-resistant roofing membrane that is well-suited for low-slope roofing projects. However, these are not as common as they were back in the day.
a. Built-Up Roofing (BUR) Membranes
Built-up roofing (BUR) membranes are a popular and time-tested choice for flat or low-sloped roofs, particularly for commercial and industrial applications. These roofing systems consist of multiple layers of reinforced fabrics, such as fiberglass or organic mats, that are intertwined with layers of hot-applied bitumen, a petroleum-based waterproofing material
Pros
- Built-up roofing systems are highly durable and can withstand heavy foot traffic, making them ideal for commercial buildings.
- The multiple layers of bitumen and reinforcing fabrics provide excellent waterproofing capabilities and resistance to ultraviolet (UV) radiation. Additionally, the gravel or slag top layer offers good fire resistance.
- When properly maintained, BUR systems can last 20 to 30 years or more and require relatively low maintenance compared to other roofing types
Cons
- BUR systems are heavy due to the multiple layers of materials, which may require additional structural support. This composition also makes installation a bit difficult and not every contractor will be able to handle this roof membrane.
- Built-up roofs are not very efficient in frigid weather, leading to cracking. Additionally, locating and repairing leaks in a BUR system can be more difficult compared to single-ply roofing systems
- The installation process can produce strong odors and fumes, which can be disruptive and potentially hazardous.
What Should You Look For When Choosing The Right Membrane?
In this blog post, we have described five types of roofing membranes. All of them are very popular options for a flat roof replacement, so how should you move forward? After learning about the different material options, you need to take a look at certain parameters.
When it comes to picking the right roofing membrane, there are quite a few things you’ll want to think about, such as your local climate, how much you’re looking to spend, and the look you’re going for. You’ll also need to consider what exactly your property needs from a roofing system.
The thing is, each type of membrane out there has its own unique pros and cons. That’s why it’s important to work closely with an experienced roofer, such as the team of Prestige Roofing LLC.
Let Experts Help You Choose The Right Membrane For You In Wisconsin
If you are thinking about installing a new flat roof, then look no further than the team at Prestige Roofing. We are the premier roofing company serving De Pere and surrounding areas in Wisconsin. We install both TPO and EPDM roofing systems. Contact us today at (920) 791-0414.