Membrane roofing systems are composed of synthetic materials compounded into flexible sheets. They are among the most popular commercial roofing materials because of their cost-effectiveness, durability, and energy-saving properties. Generally, they’re used only on flat and low-slope commercial roofs. These roofs tend to collect water, so the roofing material needs to be waterproof to prevent degradation.
This guide will walk you through the benefits of membrane roofing, common problems and how to prevent them, the most popular membrane roofing materials, and how to select the best one for your building.
Benefits of Membrane Roofing
Membrane roofing materials are a durable solution for commercial buildings with low-slope or flat roofs. Their benefits include:
- Providing an effective waterproof barrier to protect the roof deck and the interior of the building from moisture and leaks.
- Minimizing connection points and seams, reducing the risk of leaks.
- Providing cost-effective solutions.
- Improving energy efficiency through reducing the building’s cooling load during the hot summer months.
- Ability to withstand UV light, rain, wind, oils/greases/fats, and chemicals.
- Low maintenance requirements.
Common Problems with Membrane Roofing
When choosing roofing material, you should be aware of all aspects, including common problems. Luckily, with proper material selection and installation, membrane roofing performs very well.
Here are a few common problems you’ll want to be aware of:
Problem: Can be punctured or torn when exposed to excessive foot traffic, dropped tools, storm debris, or hail.
Solution: Select a membrane thickness that provides the required level of protection for your location. Also, install walk mats in high-traffic areas and limit foot traffic when possible.
Problem: Seams may fail due to membrane shrinkage or material degradation when exposed to UV light, fats, oils, greases, or chemicals, increasing the risk of water infiltration.
Solution: Ensure seams are properly sealed during installation.
Problem: Flashings around roof penetrations become loose, cracked, or otherwise damaged, increasing the potential for water leaks.
Solution: Ensure that proper flashings are installed correctly and adequately sealed around penetrations (vents, skylights, HVAC equipment).
Problem: Exposure to ultraviolet light can degrade materials, leading to brittleness, discoloration, cracking, and loss of flexibility.
Solution: Select a membrane material that’s designed to stand up to UV exposure, such as EPDM (ethylene propylene diene monomer).
Problem: Roofs with insufficient slope and/or clogged drains can create water ponding, which weakens the membrane and insulation below.
Solution: Ensure all roof areas have sufficient slope and that drainage channels are kept clear to maintain proper drainage.
Popular Membrane Roofing Materials
Membrane roofing systems are classified into two categories: single-ply and multi-layered. Materials are attached to the roof deck using fasteners (mechanical attachment), adhesives, or loose rocks or gravel. The seams between sheets are joined using heat or solvents, depending on the system. When sealed properly, they provide superior protection against water intrusion and leaks.
Single-ply membrane materials
As the name suggests, this product family requires only one layer of material to provide complete protection. While this makes installation more cost-effective, these systems are less durable than multi-layered systems. However, they still offer robust protection from the elements, oils, greases, and chemicals.
EPDM
Ethylene propylene diene monomer (EPDM) is a rubber polymer used to create a durable roofing material that lasts 20 to 50 years with regular maintenance. The synthetic rubber membrane consists of two main ingredients, ethylene and propylene, and is typically black or gray; white EPDM is also available. White roofing reflects solar heat, preventing it from being absorbed by the building and reducing cooling energy consumption.
Best for: Restaurants, areas with lots of sunshine
TPO
Thermoplastic polyolefin (TPO) roofing is made from synthetic rubber and a reinforcing fabric, making it a flexible, durable solution for a variety of commercial buildings. Its resistance to fats and oils makes it a great choice for restaurants.
It’s great at improving energy efficiency, as it reflects solar heat, reducing the need for air conditioning. It’s also cost-effective to install and is fire- and wind-resistant.
Best for: Restaurants, industrial, and healthcare buildings
PVC
Polyvinyl chloride (PVC) is slightly more flexible than TPO and is often used in the same building types, though it’s best suited for roofs with complex contours. Its durability and resistance to chemicals, oils, and fats make it great for restaurants. PVC is also fire-resistant and can withstand high winds and extreme weather. The seams are heat-welded for robust leak protection. It’s available in a variety of colors and thicknesses, providing attractive protection while improving energy efficiency.
Best for: Restaurants, healthcare buildings, locations with extreme weather conditions
Multi-layered and modified systems
These systems are often installed in multiple layers to provide advanced protection and durability when compared to single-ply systems. Asphalt, or bitumen, is modified and paired with fiberglass or felt to create a durable, waterproof material that can last for 15-20 years or more.
BUR
Built-up roofing (BUR) systems consist of multiple layers of asphalt (bitumen) and roofing felt or fabric. Loose rock or gravel is placed on the top layer to hold the membrane to the roof deck without puncturing it. Due to their multiple layers of material, BUR roofs are very durable and can handle building stress, extreme temperatures, and potential punctures.
Best for: Locations with extreme weather, high-traffic roofs
Modified bitumen or torch-down
Modified bitumen or torch-down roofing materials consist of asphalt modified with rubber or plastic, which is compressed with roofing felt to create a roofing membrane. The two main modifiers, APP (atactic polypropylene) and SBS (styrene-butadiene-styrene), increase the membrane’s flexibility and enhance its strength and durability.
Seams are joined with large flame-throwing torches, giving it its name. The heat melts the asphalt, binding the layers together. A typical installation includes two or three membrane layers attached to the roof deck with mechanical fasteners, adhesive, or rock or gravel ballast.
Best for: Industrial and healthcare buildings
How to Select the Best Membrane for Your Roof
Many factors go into selecting the best roofing membrane for your building, including roof pitch, business type, existing roof material, and roof condition. It pays to consult with a professional roofer before choosing your materials.
Contact the team at New Roofs Inc. for personalized recommendations and for a full roof assessment before selecting a membrane roofing system.