Proof Membrane

Boz Altinay Construction Industry Inc.

What is Proof Membrane? A Reliable and Long-Lasting Waterproofing Solution for Buildings.

Proof membranes are high-performance bituminous waterproofing membranes used in buildings to prevent water penetration in areas such as foundations, retaining walls, terraces, and similar structures. Typically produced with a polyester or fiberglass carrier, these membranes create a durable insulation layer, protecting the structure particularly against groundwater, rain, and soil moisture.

Where are proof membranes used?

  • In basic waterproofing systems (positive-negative insulation)
  • In curtain wall waterproofing
  • On terrace roofs
  • In parking lot pavements and retaining walls
  • In tunnel and infrastructure projects
  • In water tanks and wet areas (bathroom, toilet, under the kitchen)
  • In areas with soil moisture and groundwater risk


What are the characteristics of proof membranes? 

  •  Bitumen-Based: Modified with SBS or APP additive bitumen, it has an elastic and durable structure.
  • Carrier Layer Options: Features a structure reinforced with polyester felt, fiberglass, or composite carrier.
  • Mineral, sandblasted, or polyethylene surface options are available. 
  •  Suitable for torch-on (flame application) method.
  • It offers high tensile, rupture, and puncture resistance.

How is Proof Membrane Application Performed?

  1. Surface Preparation: The application surface must be dry, clean, smooth, and free of dust. A primer (bitumen emulsion) is applied.
  2. Membrane Installation: The roll-shaped proof membrane is adhered to the surface by heating its underside with a blowtorch.
  3. Joints: Rolls should be applied with a minimum overlap of 10 cm, and the overlap points should be carefully welded.
  4. Protective Layers: In underground applications, the layer should be covered with geotextile felt, protective concrete, or drainage board.


Advantages of Using Proof Membranes 

✔ High Water Insulation Performance

It provides 100% waterproofing against groundwater, rain, humidity, and other elements.

✔ Elastic and Flexible Structure:
Adapts to structural movements and does not crack.

✔ Ease of Application:
Torch-on application allows for quick and reliable installation.

✔ Wide Range of Applications:
Offers an effective solution in every area, from underground to the roof.

✔ Durable and Long-Lasting:
Resistant to UV rays, soil, chemical and physical effects.


Frequently Asked Questions (FAQ)

Is there a difference between proof membrane and normal bituminous membrane?

Proof membranes are generally higher density, more durable waterproofing membranes developed for specialized projects. They may vary depending on the brand and product type.

Is the product difficult to apply?

No. Fast and professional installation can be done using the torch-on (flame application) method.

Is it suitable for underground use?

Yes. It is ideal especially in foundation waterproofing systems, curtain wall insulation, and areas in contact with soil.

How many years does it last?

Depending on application quality and environmental factors, it provides effective waterproofing for 15–20 years.