Air Blown Bitumen for Roofing
Last updated: 2026-09-30
Air Blown Bitumen for Roofing: A 2025 Buyer's & Specifier's Guide
Air blown bitumen (also called oxidized bitumen or R115/15 grade) is produced by blowing hot air through vacuum residue at 240–280°C for 6–10 hours, raising softening point from ~45°C to 90–115°C. For roofing applications, this oxidized grade delivers the heat resistance, low penetration (10–20 dmm), and weathering durability that standard paving bitumen (pen 60/70) cannot match. Typical export pricing in 2025 runs $420–$520 per metric ton FOB, with minimum order quantities of 20 MT (1 flexitank) to 500 MT (bulk vessel).
What Is Air Blown Bitumen and How Is It Made?
Air blown bitumen is manufactured by oxidizing vacuum tower bottoms (short residue) with compressed air in a blowing still. The process chemically alters the molecular structure — increasing asphaltene content from ~15% to 30–40% — which raises the softening point and reduces temperature susceptibility. This is why roofing manufacturers specify it over straight-run paving grades.
| Parameter | Unit | Paving Grade (60/70) | Air Blown R115/15 | Air Blown R95/25 |
|---|---|---|---|---|
| Softening point | °C | 45–52 | 105–115 | 90–100 |
| Penetration @25°C | dmm | 60–70 | 10–20 | 20–30 |
| Flash point | °C | ≥230 | ≥240 | ≥235 |
| Solubility (toluene) | % | ≥99.0 | ≥99.0 | ≥99.0 |
| Loss on heating | % | ≤0.2 | ≤0.5 | ≤0.5 |
| Penetration index | — | -1.0 to +1.0 | +4 to +7 | +3 to +6 |
Key production data:
- Air rate: 800–1,500 m³/hour per 100 MT batch
- Blowing time: 6–10 hours depending on target softening point
- Yield loss: 2–4% (light hydrocarbons burned off as off-gas)
- Batch capacity: 200–600 MT per industrial blowing still
Why Roofing Manufacturers Choose Air Blown Bitumen
The global roofing bitumen market consumes roughly 4.2 million MT annually, and air blown grades account for about 65% of that volume. Here is why:
- Heat resistance: R115 grade softens at 105–115°C, meaning roof membranes stay dimensionally stable under summer surface temperatures that reach 70–80°C on dark membranes.
- UV/oxidation resistance: Higher asphaltene content slows photo-oxidation, extending membrane life to 15–25 years versus 8–12 for oxidized paving blends.
- Low penetration: 10–20 dmm at 25°C produces a harder, more brittle-resistant coating when reinforced with polyester or fiberglass mat.
- Adhesion: Excellent bonding to felt, glass mat, and polymer modifiers (APP/SBS), with peel strength of 2.5–4.0 N/mm in reinforced membranes.
| Application | Recommended Grade | Softening Point | Typical Loading (kg/m²) |
|---|---|---|---|
| Roofing felt (Type 15/30) | R95/25 | 90–100°C | 1.5–2.0 |
| APP modified membrane | R115/15 | 105–115°C | 2.5–4.0 |
| SBS modified membrane | R90/40 | 85–95°C | 3.0–4.5 |
| Oxidized roofing coating | R105/35 | 100–110°C | 0.8–1.5 |
| Self-adhesive underlayment | R85/25 | 85–95°C | 1.0–1.8 |
Air Blown Bitumen Specifications & Global Standards
Buyers sourcing for roofing projects must match grade to standard. The three most common benchmarks:
| Standard | Region | Test Method | Key Requirement |
|---|---|---|---|
| ASTM D312 Type III | USA | Softening point (R&B) | 100–110°C, pen 15–25 dmm |
| EN 13370 / EN 13969 | EU | Softening point | R115/15 per EN 12591 annex |
| IS 702 | India | Softening point | 90–100°C (Type 1 roofing) |
| GB/T 494 | China | Softening point | 95–115°C by class |
Practical procurement checklist:
- Softening point certificate from an accredited lab (ASTM D36 / EN 1427)
- Penetration test at 25°C (ASTM D5 / EN 1426)
- Flash point minimum 240°C for safe hot-melt processing
- Solubility ≥99% to avoid filler contamination complaints
- Batch traceability: date, blowing-still ID, and COA reference number
Typical flexitank shipping: 20 MT per 24,000L container, and a 20'
container can carry one flexitank. Bulk vessels move 5,000–30,000 MT per
cargo, with 7–14 day loading windows at major ports (Jebel Ali, Rotterdam,
Houston, Kandla).
Price, Lead Time, and Logistics Data (2025)
Air blown bitumen pricing tracks crude oil with a lag of 30–45 days and a
production premium of $60–$90/MT over straight-run vacuum residue.
| Grade | FOB Price (USD/MT) | CIF Europe (USD/MT) | CIF SE Asia (USD/MT) | Lead Time (days) |
|---|---|---|---|---|
| R85/25 | 410–450 | 465–505 | 445–485 | 10–18 |
| R95/25 | 425–465 | 480–520 | 460–500 | 10–20 |
| R105/35 | 440–480 | 495–535 | 475–515 | 12–22 |
| R115/15 | 450–500 | 505–555 | 485–530 | 14–25 |
| R125/10 | 470–520 | 525–575 | 505–550 | 15–28 |
Logistics considerations:
- Flexitank: cost-efficient for 20–200 MT orders; discharge in under 8 hours
- Drums (180 kg): best for <20 MT, adds $35–$50/MT packaging cost
- Bulk tanker: economical above 500 MT; requires heated discharge at 120–140°C
- Storage: keep at 140–160°C for max 72 hours to avoid thermal degradation
- Shelf life in drums: 24 months under cover; flexitank: 12 months
Sourcing, Quality Risk, and Compliance
The biggest risk in air blown bitumen roofing procurement is grade substitution — suppliers shipping R95/25 labeled as R115/15. Mitigation steps:
1. Third-party inspection (SGS, Intertek, Bureau Veritas) at loading port — costs $350–$600 per batch but prevents six-figure losses.
2. Retained samples from each lot, stored 24 months, for dispute resolution.
3. Pre-shipment COA matching the standard cited in your PO (ASTM, EN, or IS).
4. Payment terms: LC at sight for first orders; 30% advance / 70% against B/L copy for established relationships.
5. HS code: 2713.20 (petroleum bitumen) — confirm tariff treatment; EU import duty is 0% under most FTAs, while some markets apply 3–6.5%.
| Risk | Frequency | Mitigation Cost | Impact If Unmitigated |
|---|---|---|---|
| Grade substitution | 8–12% of shipments | $350–$600/batch | $5,000–$50,000 |
| Softening point drift | 5–8% | $150 retest | Membrane failure, warranty claims |
| Moisture contamination | 3–5% | $200/analysis | Foaming during hot-melt |
| Wrong packaging | 4–7% | Negotiated | Discharge delays, demurrage |
FAQ: Air Blown Bitumen for Roofing
Q1: What is the difference between air blown bitumen and straight-run bitumen for roofing?
Air blown bitumen is oxidized to a softening point of 90–115°C with penetration of 10–30 dmm, while straight-run paving bitumen softens at 45–52°C. Roofing requires the higher heat resistance because membrane surface temperatures can exceed 75°C in summer.
Q2: Which grade is best for APP-modified roofing membranes?
R115/15 is the industry standard for APP membranes, offering a softening point of 105–115°C and penetration of 10–20 dmm. It provides the hardness and UV stability needed for 20-year membrane warranties.
Q3: How much does air blown bitumen cost per ton in 2025?
FOB prices range from $410–$520 per metric ton depending on grade, with R115/15 typically at $450–$500/MT. CIF pricing adds $55–$65/MT for Europe and $35–$45/MT for Southeast Asia.
Q4: What is the minimum order quantity for export?
Most suppliers accept 20 MT (one flexitank in a 20' container) as the minimum, though pricing improves significantly at 100 MT+. Bulk vessel shipments start at 500 MT and offer the lowest per-ton logistics cost.
Q5: How long can air blown bitumen be stored before use?
In sealed drums, 24 months at ambient temperature; in flexitanks, 12 months. Once heated for application, keep at 140–160°C and use within 72 hours to prevent thermal hardening.
Calculate Your Roofing Bitumen Cost Now
Stop guessing at landed costs. Use the 6Tar cost calculator to model FOB price, freight, insurance, duties, and inspection fees for any air blown bitumen grade — R85/25 through R125/10 — in under 60 seconds. Enter your port pair, tonnage, and target softening point, and get a per-ton CIF figure you can take straight to procurement. Start your calculation at 6Tar today.