The roofing method is used, because it requires little maintenance in addition to providing a hermetic seal. The traditional technique of laying elastomer membrane is done by welding torch; there are two layers of elastomeric membranes; the top layer is coated with small granules to increase UV protection. The elastomeric membrane has a life expectancy of 20 years, but a good ventilation of the building may extend its lifespan up to 30.

• Provides absolute tightness
• Requires little maintenance
• Lifespan of 20-30 years
• Finishing coat with color granules