What is single-ply roofing? You’ve come to the right place to find out! In this article, you will find answers to the following questions:

1. What is single-ply roofing?
2. What are the main types of single-ply roofs?
3. How are single-ply roofing systems installed?
4. What materials are used in single-ply roofs?
5. What is the longevity of a single-ply roof?

What is Single-Ply Roofing?

Single-ply roofing is classified as flexible sheets of compounded plastic-derived material that are used to cover and protect flat and low-sloped buildings. These prefabricated membranes are manufactured in a factory to strict quality control requirements and can be attached in a variety of methods. In the last 30 years, single-ply roofing has displaced older materials, such as tar paper, as the go-to roofing material for commercial roofing contractors. Properly installed, single-ply roofing systems offer an inherent advantage over traditional materials due to their strength, flexibility, and high durability. 

What are the Main Types of Single-Ply Roofs?

There are three main types of single-ply roofs:

1. Thermoplastic Polyolefin (TPO)
2. Polyvinyl Chloride (PVC)
3. Ethylene Propylene Diene Monomer (EPDM)

PVC membrane roofs have been in use for decades. They are time tested and still a popular roofing system. For many years, EPDM roofing had been the top choice for single-ply roofing. However, TPO roofing is considered the gold standard of roofing materials.

How are Single-Ply Roofing Systems Installed?

There are four primary methods for installing single-ply roofing systems:

• The Mechanically Attached System: This system fastens the flat roofing in place by first fixing mounting plates through the insulation to the roof deck, laying the membrane in place, and then attaching it to the underlying plates.
• The Fully Adhered System: This system can be used in roofs that have a little bit of slope to them. The mounting plates are used to anchor the roof insulation to the roof deck and then the single-ply roofing is bonded directly to the insulation.
• Induction-Welded Roof Installation: When mechanical attachment is not possible, an induction-welded roof system can decrease the amount of penetrating fasteners by up to 50 percent.
• The Ballasted System: This system provides fast coverage at minimal cost. It utilizes large panels of rubber roofing membrane, up to 50 feet by 200 feet, loose-laid on the insulation and then covered by approved ballast, such as river-washed stone.

What Materials are Used in Single-Ply Roofs?

There are two types of roofing materials used in single-ply roofs: thermosets and thermoplastics. First, thermoset roof systems are usually made of ethylene propylene diene monomer (EPDM). This type of material is excellent for roofing because it is flexible and very resistant to abrasion damage, weathering, high heat, and ultraviolet light. EPDM material is very similar to rubber. It is considered low maintenance and easy to repair. Typically, EPDM is black but may be available in white as well. Black EPDM membranes absorb solar energy effectively, which can reduce heating costs during the winter. 

Next, thermoplastic roof systems use thermoplastic polyolefin (TPO) or polyvinyl chloride (PVC) membranes. Both of these membranes are very resistant to weather and ultraviolet light, as well as holes. TPO roofing systems are becoming more popular in the commercial roofing industry, especially in southern climates. Reductions in energy consumption and costs have been attributed to light-colored TPO membranes. Typically, TPO membranes are white but may be available in other colors as well. PVC roofing systems show potential for decreases in energy costs too. PVC provides efficient resistance to chemicals. Most PVC systems are white as well, though other colors are also available. 

What is the Longevity of a Single-Ply Roof?

A typical single ply membrane flat roof system can be expected to achieve a service life of at least 30 years. Care should be taken to distinguish between the durability of the single ply membrane by itself, and the expected service life of the flat roof system incorporating the membrane.

As the components are exposed to the elements and any foot traffic, the single ply membrane has a role in protecting the components immediately below it. However, the performance and durability of the complete roof system depends on all materials being stored and handled correctly, installed in accordance with manufacturer’s instructions, and fixed in accordance with wind uplift calculations etc.

How do other components contribute to the service life of a flat roof? In isolation, any of the other components in a flat roof are capable of offering a similar, if not longer, durability to the single ply membrane. Thermal insulation, for example, is often quoted as having a potentially indefinite service life.

The key is really in compatibility of products and quality of workmanship, to make sure that durability is not compromised by poor installation, inadequate fixing, or poor drainage – anything that could put unnecessary stress on the flat roof system and its components.

At ShenCorp Inc., we often recommend that our customers install single-ply roofing for their homes and businesses. Single-ply membrane roof systems are lightweight, affordable, and flexible. If you’re interested in installation or repair of single-ply roofing systems – commercial or industrial – we can help. 

Whatever your roofing needs, we are here to help! Since 1977, ShenCorp Inc. has specialized in commercial roofing throughout Winchester, VA, Charlottesville, VA, Waynesboro, VA, Richmond, VA, Virginia Beach, VA, and other parts of the Mid-Atlantic region. Call ShenCorp for your total roofing services.