Comparison of Roofing Membranes & Liquid Applied Coatings

A commercial roof creates a watertight surface. Let’s discuss roofing membranes – specifically single-ply roofing membranes or liquid-applied coatings. A roof waterproofing membrane can prevent water seepage into your building structure caused by rain, humidity, or melting snow and ice.

Single Ply Roofing Membrane

Single-ply roofing systems for buildings are installed by applying a single flexible layer of material over the building’s insulation or roof deck. The industry has three main types: TPO, PVC, and EPDM.

Much has been written comparing the pros and cons of these commercial roofing membranes. TPO (thermoplastic polyolefin), PVC (polyvinyl chloride), and EPDM (ethylene propylene diene monomer) are all resistant to UV radiation and harsh environmental conditions.

The sheets come in various grades and thicknesses so that you can select the correct type of membrane for your budget and environment. Some can be applied over the top of an existing roof system. And these single-ply roofing systems are manufactured in a factory under strict quality control guidelines, so there will be no cracks and no question about the level of protection each offers.

Be sure that the roofing system that you choose meets your local building codes and insurance requirements.  Thermoplastics like TPO and PVC have reinforced membranes that are welded together and are typically white, grey, or tan.  EPDM is available in reinforced or non-reinforced sheets, use tapes or glue for seaming, and is most commonly black.

Single-Ply Roof  Membrane Attachment and Cost Considerations

The installation cost of each roofing membrane can vary widely from roof to roof.  The height, age, size, condition, and number of penetrations on the roof are all factors that are taken into consideration.  

If a roof is large, wide open, and can withstand 10 pounds per square foot of rocks on it, ballasted EPDM is often a low-cost alternative that makes sense. 

Mechanically fastened TPO systems commonly provide the lowest installed cost on roofs in the United States.  PVC and EPDM mechanically attached systems tend to cost slightly more.

Adhered systems secure the membrane to the substrate without any billowing, like you will find on mechanically attached systems, but they also tend to cost the most per square foot for TPO, PVC, or EPDM assemblies.

Liquid Applied Coatings 

Liquid-applied roofing products are made with resin and reinforced polyester. The product gets sprayed on or applied by a roller – usually in two coats. There are no seams in this type of system.  Although sometimes used to repair or extend the life of a low-slope roof, they are more commonly used on aged metal roofing systems.

Besides providing a seamless coating, liquid-applied roofing often eliminates the need to tear off the existing roof system, which helps reduce costs and risks associated with the tear-off process. 

The cost of commercial roof coating systems tends to be less expensive than a complete roof tear-off and replacement and can reduce the need for roof repairs. 

Which Roofing Membrane is Right For Your Commercial Building? Contact Nations Roof

A roof coating system (or a liquid-applied roof membrane) may be a cost-effective solution for your business situation. However, it’s only suitable for some types of commercial roofs. Contact Nations Roof, the premier commercial roofing contractor in the country, to learn whether PVC, TPO, EPDM, roof coating, – or another type of system is the best choice for your situation.

Roof Waterproofing Membrane: Key Takeaways

• There are different types of waterproofing membranes, and some may be applied over your current roofing materials to help prevent leaks. 
• PVC, TPO, and EPDM are single-ply roofing membranes used on low-slope roofs.
• Liquid-applied membranes are cost-effective solutions that can prolong the life of some commercial roofs.