There are numerous types of waterproofing membranes that are present in the market, each having distinct characteristics and usage.
Some important types are detailed below:
1. Liquid-Applied Membrane
Description: Essentially a liquid application that dries to be a seamless, impervious layer.
Types:
Polyurethane: Very high in flexibility and hence, the best for places where movement or vibration can happen. The durability and chemical
resistance is very good.
Acrylic: Water-based, easy to apply, and relatively cheap. Appropriate for uses which are not that highly exposed.
Bitumen-Based: Often used in combination with other materials; sometimes modified with polymers to function better.
Uses: Flat roofs, balconies, terraces, and below-grade walls.
2. Sheet Membranes
Definition: Prefabricated sheets that are rolled onto the surface of the substrate and bonded or fastened mechanically.
Types:
Bitumen-Based: Consists of bitumen membranes modified with SBS or APP. For the roofing and below-grade works. Ensures perfect
waterproofing properties with the combined power of strength and durability.
EPDM (Ethylene Propylene Diene Monomer): This particular synthetic rubber membrane is highly popular because of its flexibility,
robustness, and weather resistance against UV. Usually applied on flat roofs.
PVC (Polyvinyl Chloride): Enduring, resistant to UV. Welding at seams is very easy with this kind. The usual places it is used are roofing
and waterproofing applications.
TPO (Thermoplastic Olefin):Reflective and energy-efficient, with strong resistance to UV and weathering; best suited for flat roofing and
exposed applications. Applications: Used in roofing, foundation walls, and below-grade structures.
3. Cementitious Membrane Description: Coatings that consist of cement-based compounds mixed with water and applied in the plastic
state to cure as a hard waterproof layer.
Types: Single-Component: Available in prepackaged form and needs only water for mixing before application.
Two-Component: Available as two different parts—one part being powder and another part being liquid—which are mixed to formulate
an application.
4. Self-Adhesive Membranes
Description: These are membranes that are coated with an adhesive on one side and pushed into direct placement on the surface
without the use of adhesives.
Types:
Modified Bitumen: Uses a self-adhesive backing for increased ease of application. Ideal for use below grade and foundation walls.
Applications: foundations, retaining walls, and work where fast application processes are advantageous
5. Thermoplastic Membranes
Description: This material applies to membranes that become pliable when heated to bond at laps. These are also heat-welded at end
laps.
Types:
TPO—Thermoplastic Olefin: It is energy efficient, UV and chemical resistant; primarily used in roofing.
PVC—Polyvinyl Chloride: It is very durable and flexible; used for a variety of waterproofing applications.
Application: Waterproofing for flat roofs, large commercial area, and industrial environment.
6. Elastomeric Membranes
Description: It is an extremely flexible membrane; it can stretch and return to its original shape.
Types:
EPDM—Ethylene Propylene Diene Monomer: It is the most flexible and weather-resistant elastomeric membrane.
Neoprene: Good resistance to chemicals plus flexible.
Uses: For Roofing and wet applications, high flexibility uses
7. Composite Membranes
Definition: A membrane fabricated of two materials for performance increase
Types:
Membranes of bituminous and Reinforcement: The reinforcement in the bituminous membrane material is done to increase the material's strength and flexibility.
Multi-layer Systems: Multiple single-ply or multi-ply membranes of different types that are made thus offering increased performance or two or more types of materials in a single system.
Uses: Performance uses that require strengths and increased durability
Selection criteria for Membrane:
Surface Type: Compatibility with the substrate concrete, metal, wood, and membranes.
Exposure Conditions: UV exposure, temperature extremes, chemical exposure.
Flexibility and Movement: Some membranes have flexible properties and are hence more suited in areas of high movement or vibration.
Application Type: Liquid-applied, sheet, self-adhesive; based on the complexity of the application method and surface conditions.
Budget: Your prices are all over the board, so you've really got to look at what the installation costs are and the maintenance – anything to do with the membrane.
The correct selection of waterproofing membrane actually depends on multiple project requirements: climatic and environmental conditions, type of structure, and anticipated life of the waterproofing system.