Bitumen Membrane — Overview
Bitumen membranes are flexible waterproofing sheets based on oxidized (blown) bitumen, reinforced with a polyester or fiberglass carrier. As one of the most widely used waterproofing materials in the construction industry, bitumen membranes offer reliable, cost-effective protection against water and moisture penetration.
RAHA Gilsonite Co. manufactures and supplies high-quality bitumen membranes produced from premium oxidized bitumen grades (75/25, 85/25, 90/40), ensuring consistent quality and proven field performance.
Product Features
| Feature | Specification |
|---|---|
| Base material | Oxidized bitumen (75/25, 85/25, 90/40) |
| Carrier | Polyester felt / Fiberglass mat / Composite |
| Top surface | Mineral granules / Polyethylene film / Sand |
| Bottom surface | Polyethylene film / Sand |
| Thickness | 2–5 mm |
| Roll width | 1 m |
| Roll length | 10 m |
| Weight per roll | 35–50 kg |
Technical Specifications
| Property | Value | Test Method |
|---|---|---|
| Softening point of bitumen | 75–90°C | ASTM D36 |
| Penetration of bitumen | 15–40 dmm | ASTM D5 |
| Tensile strength | ≥ 500 N/50mm | EN 12311-1 |
| Elongation at break | ≥ 30% | EN 12311-1 |
| Cold flexibility | -5°C | EN 1109 |
| Heat resistance | 100°C | EN 1110 |
| Water impermeability | Pass | EN 1928 |
| Thickness tolerance | ± 0.2 mm | EN 1849-1 |
Applications
Roofing: Flat roofs, pitched roofs, industrial roofing
Damp proofing: Below-ground walls, floor slabs
Tanking: Basement waterproofing systems
Civil works: Bridge deck waterproofing, tunnel linings
Industrial: Reservoirs, ponds, secondary containment
Installation Methods
Torch-Applied The most common installation method. The underside of the membrane is heated with a propane torch to melt the bitumen, fusing it to the substrate or previous layer.
Cold-Applied The membrane is bonded using a cold bitumen adhesive or primer. Suitable for substrates where open flame is prohibited.
Mechanical Fixation The membrane is mechanically fastened to the substrate using approved fasteners, typically used in re-roofing or inverted roof assemblies.
Advantages
- ✅ Cost-effective — lower cost than polymer-modified alternatives
- ✅ Proven performance — over 50 years of successful use worldwide
- ✅ Easy application — torch or cold-applied
- ✅ Good adhesion — bonds reliably to concrete, wood, and metal
- ✅ Water-tight — zero permeability when correctly installed
- ✅ Available in multiple thicknesses and surface finishes
Quality Standards
- EN 13707 — Reinforced bitumen sheets for roof waterproofing
- EN 13969 — Bitumen damp proof sheets
- BS 747 — Specification for roofing felts
- ASTM D173 — Bitumen-saturated cotton fabrics
