Bitumen membranes are the most widely used method of roof waterproofing in Greece. With correct application and quality materials, they protect a roof for 25-30 years. But the market is full of products of very different quality, from cheap 3kg APP to premium 6kg SBS, and the choice affects everything: from lifespan to resistance to cold.
In this guide you will learn exactly what bitumen membranes are, the differences between types, what to ask a contractor for, and when they are the best choice for your roof.
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Bitumen membranes (or bituminous membranes) are flexible waterproofing membranes made from specially processed bitumen reinforced with polymer modifiers, laid on a carrier of polyester or glass fibre. They are applied by torch-on heat welding, creating a continuous waterproof membrane.
The structure of a bitumen membrane, from the outside in:
The weight ranges from 3 kg/m² (cheap products) to 6 kg/m² (premium quality). More weight means more bitumen compound and a longer lifespan.
The most critical selection factor is neither the weight nor the price. It is the type of polymer modifier:
SBS bitumen membranes are reinforced with elastomeric polymers that give them "elastic memory": they deform and return to their original shape. This means excellent flexibility down to -20°C; they follow the contraction and expansion of the concrete without cracking, and they have a lifespan of 25-30 years.
They withstand high temperatures better but become brittle at low ones. For the Greek climate, with its sharp temperature swings, this is a serious drawback.
| Feature | SBS | APP |
|---|---|---|
| Flexibility in the cold | ✅ Down to -20°C | ❌ Brittle below 0°C |
| Heat resistance | ✅ Good | ✅ Excellent |
| Lifespan | ✅ 25-30 years | ⚠️ 15-20 years |
| Suitable for Greece | ✅ Yes | ✅ Yes |
Read more about Roof Waterproofing with Bitumen Membranes
Spunbond polyester 180 gr: High tensile strength and excellent flexibility. It bridges cracks and follows movements of the substrate. The choice for professional applications.
Glass fibre: Lower cost, good tensile strength but less flexibility. Suitable for simpler applications or as the bottom layer in two-layer systems.
Mineral granules (white or grey): The best choice for exposed roofs. They reflect heat and protect against UV and mechanical wear. The Dien Energy++ SBS 6kg with white mineral granules that we use has a lifespan of 25-30 years.
Aluminium: High reflectivity. It is an absolute vapour barrier and requires a perforated base layer and vapour vents. Without proper preparation it almost always leads to failure.
Quartz sand: Used mainly as a bottom finish or on bitumen membranes that will be covered with another material. It is not recommended as a final exposed surface. Read more about quartz sand in roof insulation.
Single layer: Primer + 1 layer of SBS 6kg + reinforcement of vulnerable points. From €25/m² (plus VAT).
Double layer: Primer + 2 layers of SBS (4kg and 6kg) + reinforcement with Hyperdesmo PB1K. Maximum lifespan of 30-35 years. From €45/m² (plus VAT).
For detailed prices, see the roof insulation price guide.
At Goumas Insulation we apply exclusively Dien Energy++ SBS 6kg with white mineral granules:
See waterproofing with bitumen membranes in detail
Every roof has different needs, and the right solution can only be determined after an on-site inspection. With 25+ years of experience, certified crews and a written guarantee for every project, Goumas Insulation ensures the right solution for your roof.
Elastomeric bituminous membranes reinforced with SBS polymers. They retain high flexibility down to -20°C and have a lifespan of 25-30 years with correct application.
SBS membranes have elastic "memory" and withstand the cold. APP membranes become brittle at low temperatures. For the Greek climate, SBS is clearly the superior choice.
SBS 6kg with correct application: 25-30 years. Double-layer SBS: 30-35 years. Cheap APP or low-weight products have a significantly shorter lifespan.
Bitumen membranes for large surfaces and maximum lifespan. Hyperdesmo for complex roofs with many penetrations. They are often combined. See waterproofing with Hyperdesmo.
For exposed roofs, always mineral granules. Aluminium requires a perforated base layer and vapour vents. Without proper preparation it almost always fails.
Mould caused by roof leaks is solved with proper waterproofing. If it is caused by thermal bridges, the solution is external wall insulation (ETICS). Read about mould on walls.
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