Waterproofing Mini-Lesson | Materials Science: What You Need to Know About TPO and PVC Product Types

In recent years, with the advancement and deployment of carbon peaking and carbon neutrality initiatives, high-performance PVC and TPO polymer waterproof membranes, which offer energy savings and environmental benefits, have experienced rapid growth in China. Due to their superior physical properties, they exhibit exceptionally long-lasting aging resistance when used directly exposed, and have long held the position of "King of Roofing" in the North American market.

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When choosing PVC and TPO polymer membranes, consumers may understand the differences based on thickness using common sense, but they often encounter product type designations such as L-type, P-type, and G-type, which may be confusing. What do these designations mean? How can consumers choose the right type for their needs?

Today, Canlon, as a benchmark enterprise in the industry covering all national and European standards for TPO/PVC products, will help you quickly understand the basics—

Canlon Imported PVC Production Line

Polyvinyl chloride (PVC) waterproof membrane is made primarily from polyvinyl chloride resin, with the addition of various chemical additives, and processed through compounding, extrusion, or calendering. It conforms to the current national standard GB 12952, "Polyvinyl Chloride (PVC) Waterproof Membrane". Based on product composition, it can be divided into the following conventional types—

Homogeneous membrane material (code H)

Fiber-backed membrane material (code L)

Fabric-reinforced membrane (code P)

Fiberglass reinforced membrane (code G)

Fiberglass reinforced inner tape fiber-backed membrane material (code GL)

Thermoplastic polyolefin (TPO) waterproof membranes are made primarily from polymers of ethylene and alpha-olefins, and comply with the current national standard GB 27789, "Thermoplastic Polyolefin (TPO) Waterproof Membranes". Based on product composition, they can be divided into the following conventional types—

Homogeneous membrane material (code H)

Fiber-backed membrane material (code L)

Fabric-reinforced membrane (code P)

1. What is H-type?

H-type (homogeneous) refers to membrane materials that do not contain reinforcing ribs or backing, have a uniform texture, and are generally not used as the main construction material, but rather as an auxiliary material for P-type and L-type membrane materials. This is because TPO and PVC themselves have excellent weather resistance and good physical properties.

Due to thermal expansion and contraction, homogeneous (H-type) membrane materials shrink and deform significantly below -5℃, making them prone to wrinkling. In contrast, P-type membrane materials with reinforcing ribs do not have this problem.

2. What is a P-type?

P-Type (internal fabric reinforcement) refers to waterproofing membranes with an internal fabric reinforcement mesh, resulting in excellent maximum tensile strength and elongation at break. Suitable for waterproofing layers in exposed roofs and underground projects where high material strength is required, it is commonly used in roof waterproofing projects constructed using mechanical fastening methods.

3. What is L-type?

L-Type (with fiber backing) refers to a membrane material with a layer of fiber felt laminated on the back, which enhances the material's shape retention. It is suitable for waterproofing layers on non-exposed roofs and underground projects, and is applicable to waterproofing projects constructed using the full-adhesion method or the loose-lay coping method.

4. What is G-type?

G-Type (glass fiber reinforced) refers to membranes with chopped glass fibers or glass fiber nonwoven fabric added to improve the dimensional stability and anti-aging properties of the membranes. It is suitable for projects with high requirements for waterproofing performance and durability, as well as waterproofing projects that are exposed to outdoor environments for a long time.

5. What is the GL-type?

GL-type (glass fiber reinforced with fiber backing) refers to membranes that combine glass fiber reinforcement and fiber backing, making them a double-reinforced model suitable for waterproofing projects in complex environments.

In short, P-type typically emphasizes internal reinforcement to improve mechanical properties; L-type focuses on backing reinforcement to facilitate bonding and shaping; and GL-type is a composite reinforcement.

For exposed roofs where strength is a priority, PVC or TPO P-type (internal reinforcement) roofing membranes are the best choice.

For roof mechanical fixing systems, TPO P-type (internal reinforcement) membranes are very suitable.

For waterproofing of non-exposed roofs or basements, L-type (backed) membranes of PVC or TPO are a common choice.

If you have a more specific application scenario (such as roof repair, basement damp-proofing, etc.) and are unsure how to choose materials, please feel free to contact Canlon. We will provide you with a deeply customized system solution for reference!