The Sika Group has acquired a majority stake in Index Construction Systems and Products, a leading Italian manufacturer of roofing and waterproofing systems. Index is known for its superior range of high-quality bitumen membrane solutions. As a popular roofing material choice, bitumen offers versatility, durability, cost-effectiveness and, above all, it is highly waterproof.
What should be considered when choosing a bitumen membrane?
The temperature, exposure and local weather determine the type of compound type – be it elastomeric, plastomeric, elastoplastomeric or oxidised bitumen.
- Smooth surfaces such as talc, sand and PE foil are indicated for ballast systems, or as a base sheet in a multi-layer system.
- Covered membranes such as granulated surfaces protect the compound and can be used as an exposed layer.
- Polyester increases the strength and elongation.
- Glass fibre increases the dimensional stability.
- Aluminium works as a vapour barrier.
* The type of reinforcement defines the system build-up and whether the membrane should be applied in a single or double layer.
Aging tests are strongly recommended, as are tests to check thermo-oxidisation.
These include fire performance, local approvals, certifications, required anti-root materials and safety considerations during the application process.
Key variables of bituminous membranes:
- Cold flexibility: Directly related to weather conditions and the life expectancy of the membrane. The lower the flexibility, the higher the durability.
- Reinforcement: Strength (tensile force), elongation and tear-and-shear resistance.
- Top surface: Smooth for non-exposed roofs, below-ground applications or self-protected surfaces for exposed roofs and the upper layer in multi-layer systems.
Issue: Choosing the correct bitumen membrane.
Solution: With over 100 years of waterproofing experience, Sika identifies the factors and variables to consider.
For more information, contact Sika:
Tel: +27 31 792 6500