Oxidized bitumen 95/25 is the grade buyers reach for when 85/25 is not quite enough and 105/35 costs more than the project needs. It carries the same 20 to 30 dmm penetration as the world’s volume roofing grade but adds roughly 10 °C of softening point. In a market where summer roof surfaces touch 80 °C, that margin is the difference between a membrane that holds and one that flows at the laps.
RAHA Gilsonite supplies oxidized bitumen 95/25 against ASTM D312, BS EN 13304:2009 or a buyer’s own specification. This page covers the specification, the climate band the grade actually suits, melting and coating temperatures, and the three-way comparison against 85/25 and 105/35 that decides most orders.
What is oxidized bitumen 95/25?
Oxidized bitumen, also called blown bitumen or blown asphalt, is produced by blowing air through hot penetration grade bitumen at around 240 to 260 °C. Oxygen reacts with the maltene fraction and converts it toward asphaltenes. The binder becomes harder, the softening point climbs and the penetration falls.
Reading the designation
The grade name reads softening point over penetration. In oxidized bitumen 95/25, the 95 is the ring-and-ball softening point in degrees Celsius and the 25 is the penetration at 25 °C in tenths of a millimetre. Under BS EN 13304:2009, oxidised grades are expressed as multiples of 5, so 95/25 is a standard-defined grade within that European framework.
The grade that fills the gap
Most of the world’s roofing membrane is coated with 85/25. It works, it is the cheapest option in the flexible range, and in temperate climates nothing more is needed. The problem appears in markets that are hot but not extreme — the Mediterranean, southern Europe, southern China, much of Latin America, coastal East Africa. There, a dark roof reaches 75 to 82 °C in high summer, which sits uncomfortably close to the 80 to 90 °C softening band of 85/25.
Moving to 105/35 solves it but is a larger step in both specification and cost. 95/25 is the intermediate answer: same hardness as 85/25, roughly 10 °C more heat margin, and a smaller price differential than the jump to 105.
The rule of thumb. Take the highest recorded ambient temperature at the installation site and add 30 to 35 °C for a dark roof surface in direct sun. If that figure lands within 10 °C of the binder’s softening point, the grade is too soft. A 48 °C summer means an 80 °C roof, and 85/25 is already marginal.
Oxidized bitumen 95/25 specification
| Property | Unit | Specification | Typical result | Test method |
|---|---|---|---|---|
| Softening point (ring & ball) | °C | 90–100 | 95 | ASTM D36 / EN 1427 |
| Penetration @25 °C, 100 g, 5 s | dmm | 20–30 | 25 | ASTM D5 / EN 1426 |
| Loss on heating | wt % | 0.5 max | 0.2 | ASTM D6 |
| Flash point (Cleveland open cup) | °C | 245 min | 270 | ASTM D92 |
| Solubility in trichloroethylene | wt % | 99 min | 99.5 | ASTM D2042 |
| Specific gravity @25 °C | — | 1.00–1.06 | 1.03 | ASTM D70 |
| Ductility @25 °C | cm | 2.5 min | 2.5–4 | ASTM D113 |
| Ash content | wt % | 0.5 max | 0.2 | ASTM D2939 |
| Spot test | — | Negative | Negative | AASHTO T102 |
Ductility remains a meaningful limit at 25 dmm and is worth having on the certificate for any membrane application. Test methods are maintained by ASTM International. Where a project names a specification that differs from the values above, send us the specification rather than the grade name and we will confirm what meets it.
Applications of oxidized bitumen 95/25
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Roofing felt and membrane
The primary use. Coating compound for bitumen felt and torch-on membrane destined for warm-temperate and subtropical markets where 85/25 is marginal.
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Damp proof course
DPC sheet manufacture where the roll may be stored or transported through summer heat before installation.
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Below-grade waterproofing
Foundation and basement tanking, and podium deck waterproofing beneath paving or landscaping.
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Bridge deck waterproofing
Under the wearing course, where the membrane sees paving temperatures during construction and traffic heat afterwards.
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Built-up roofing
Mopping and bonding compound between plies in multi-layer systems.
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Construction adhesives and mastics
Board and insulation bonding, jointing compounds and general bituminous adhesive work in warm climates.
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Pipe wrapping and coating
Wrapping tape compounds and coating for pipe laid in warm ground, where some flexibility during installation is still required.
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Sound damping compounds
Automotive and appliance damping pads, particularly where the vehicle or unit will operate in hot climates.
Where a different grade fits better
For genuinely extreme heat — Gulf states, Saharan interior, equatorial Africa, inland India in summer — move to 105/35 or 115/15. For cold-winter markets where the sheet must survive folding in low temperature, 90/40 or 85/40 give more flexibility. For static industrial compounds and pipe coating enamel, the harder 105/15 or 90/10 resist creep better.
The three-way comparison: 85/25, 95/25 and 105/35
These three cover most roofing membrane production worldwide, and choosing between them is the decision this page exists to answer.
| 85/25 | 95/25 | 105/35 | |
|---|---|---|---|
| Softening point | 80–90 °C | 90–100 °C | 100–110 °C |
| Penetration | 20–30 dmm | 20–30 dmm | 30–40 dmm |
| Suits ambient up to | About 42 °C | About 50 °C | Above 50 °C |
| Typical markets | Europe, temperate Asia, highland Africa | Mediterranean, southern China, Latin America, coastal East Africa | Gulf, North Africa, South Asia, equatorial belt |
| Flexibility at ambient | Moderate | Moderate — same as 85/25 | Higher despite the hotter rating |
| Relative cost | Lowest | Modest premium | Highest of the three |
| Coating temperature | 170–195 °C | 185–210 °C | 190–215 °C |
The row worth reading twice is flexibility. 105/35 is rated 15 °C hotter than 95/25 yet carries more penetration, not less. That is because it has been blown from a different starting point rather than simply blown further. If your line needs both heat resistance and fold tolerance, 105/35 is technically superior — 95/25 is the choice when the budget will not stretch and the climate does not demand it.
How 95/25 compares with the full oxidized range
| Grade | Softening point | Penetration | Class | Principal use |
|---|---|---|---|---|
| 150/5 | 145–155 °C | 0–10 dmm | Hardest | Electrical compounds, battery sealing, pipe enamel, rubber |
| 115/15 | 110–120 °C | 10–20 dmm | Hard | Waterproofing, adhesives, sealing, pipe coating |
| 105/35 | 100–110 °C | 30–40 dmm | Medium | Membrane for hot climates |
| 105/15 | 100–110 °C | 10–20 dmm | Hard | Sealing, jointing, industrial mastics |
| 95/25 | 90–100 °C | 20–30 dmm | Medium | Membrane and damp proofing in warm-temperate markets |
| 90/40 | 85–95 °C | 35–45 dmm | Softer | Membrane for temperate and cool climates |
| 90/15 | 85–95 °C | 10–20 dmm | Medium | Adhesive and sealing work |
| 90/10 | 85–95 °C | 5–15 dmm | Hard | Pipe coating, industrial compounds |
| 85/40 | 80–90 °C | 35–45 dmm | Softer | Membrane and DPC in cold climates |
| 85/25 | 80–90 °C | 20–30 dmm | Medium | The volume roofing grade worldwide |
| 75/35 | 70–80 °C | 30–40 dmm | Softest | Damp proofing, low-temperature climates |
| 75/25 | 70–80 °C | 20–30 dmm | Softest | General waterproofing, jointing |
The full range is listed on our oxidized bitumen grades page.
Melting and coating temperatures
| Operation | Temperature | Notes |
|---|---|---|
| Melting | 165–190 °C | Indirect heating. Melt the full charge and homogenise before drawing off |
| Pumping | 175–195 °C | Heat traced lines. The grade sets in cold pipework |
| Coating / application | 185–210 °C | Membrane lines typically run at the upper end for even film thickness |
| Absolute maximum | 225 °C | Above this the material cokes and the softening point drifts upward |
| Hot holding | Limit to a working shift | Prolonged holding continues the blowing reaction and hardens the grade |
Overheating pushes 95/25 toward 100/20 territory — harder and more brittle than what you specified. Because the whole point of choosing this grade over 105/35 is cost, arriving at a harder product than intended defeats the purpose. Log the tank temperature and test the penetration on the finished sheet, not only on the incoming bags.
Safety
The flash point is 245 °C minimum, so there is margin against the working range, but fume generation and thermal burn risk are real at these temperatures. Because bitumen is a poor conductor of heat, the melting phase must be controlled to prevent localised overheating. If the material foams, spits or crackles as it heats, water is present — stop heating rather than trying to drive it off. Handling guidance is published by Eurobitume and the Asphalt Institute.
Packing, storage and shipping
| Packing | Unit weight | Per 20′ container | Notes |
|---|---|---|---|
| Kraft paper bag | 25 kg | Up to 25 MT palletised | Most common. Meltable bag options available so the bag goes into the melter |
| PP bag | 25 kg | Up to 25 MT palletised | Palletised and shrink wrapped |
| Carton box | 25 kg | Up to 22 MT | Better protection for long transit and rough handling |
| New steel drum | 180–190 kg | 80 drums ≈ 15 MT | Requires cutting or a drum melter at destination |
Storage and shelf life
Two to three years in sealed packing kept dry and out of direct sun. Because the material is already fully blown there is little left for atmospheric oxygen to react with, so chemical ageing runs slowly.
95/25 stores better than the softer grades. At 25 dmm the blocks stay firm enough that stack fusion is much less of a problem than with 90/40 or 105/35, which matters on a long sea leg where container temperatures reach 60 to 70 °C. Standard practice still applies: pallets, under cover, no more than two tiers, batch number filed with the certificate of analysis.
Customs classification
The grade falls under HS 2713.20, petroleum bitumen. Bagged and drummed material at ambient temperature is generally not classified as dangerous goods for sea carriage, although most shipping lines and destination customs still require the safety data sheet with the booking. Note that gilsonite and other natural bitumen fall under a different heading.
Quality control and certification
Every shipment leaves with a batch certificate of analysis stating the lot number, the production date, the standard tested against and each test with its method and measured result. We accept third-party inspection at loading by SGS, Bureau Veritas, Intertek or any surveyor named in your contract.
What to check for this grade
Check where the softening point actually lands inside the 90 to 100 °C window. A batch at 91 °C is barely distinguishable from a good 85/25 and gives you little of the heat margin you paid the premium for. A batch at 98 °C delivers the full benefit. If your reason for choosing 95/25 over 85/25 is climate rather than habit, contract to a narrower band — for example 94 to 98 °C — rather than accepting the full range.
Frequently asked questions about oxidized bitumen 95/25
What does 95/25 mean in oxidized bitumen?
The first number is the ring-and-ball softening point in degrees Celsius, so approximately 95 °C. The second is the penetration at 25 °C in tenths of a millimetre, so approximately 25 dmm. The specification runs 90–100 °C for softening point and 20–30 dmm for penetration.
What is oxidized bitumen 95/25 used for?
Principally roofing felt and membrane manufacture for warm-temperate and subtropical markets, plus damp proof course sheet, below-grade waterproofing, bridge deck waterproofing, built-up roofing compounds, construction adhesives, pipe wrapping and sound damping compounds.
What is the difference between 95/25 and 85/25?
They share the same penetration band of 20 to 30 dmm, so they behave similarly at ambient temperature. The difference is roughly 10 °C of softening point — 90 to 100 °C against 80 to 90. That margin matters where a dark roof surface reaches 75 to 82 °C in summer, which is where 85/25 becomes marginal and 95/25 still holds.
Should I choose 95/25 or 105/35?
105/35 is technically superior for membrane: it holds 10 °C more softening point and more penetration, so it resists heat better without losing fold tolerance. 95/25 is the right choice when the climate does not demand that much heat margin and the cost difference matters. For the Gulf, North Africa, South Asia or the equatorial belt, specify 105/35.
How do I know if a grade is hot enough for my climate?
Take the highest recorded ambient temperature at the installation site and add 30 to 35 °C for a dark roof surface in direct sun. If that figure lands within 10 °C of the binder’s softening point, the grade is too soft. A 48 °C summer implies an 80 °C roof surface, at which point 85/25 is already marginal and 95/25 is the minimum.
What temperature do I melt oxidized bitumen 95/25 at?
Melt at 165 to 190 °C, pump at 175 to 195 °C and coat at 185 to 210 °C, using indirect heating. Do not exceed 225 °C. Overheating pushes the grade harder than specified, which defeats the reason for choosing it over a harder grade in the first place.
Is oxidized bitumen 95/25 the same as blown asphalt 95/25?
Yes. Oxidized bitumen, blown bitumen and blown asphalt all describe the same product — penetration grade bitumen air-blown at high temperature to raise the softening point and reduce the penetration. The naming varies by region rather than by product.
Does 95/25 have a ductility requirement?
Yes, typically 2.5 cm minimum at 25 °C. Ductility remains meaningful at this penetration and is worth having on the certificate for any membrane application, since it indicates whether the finished sheet will crack when folded.
What is the shelf life of oxidized bitumen 95/25?
Two to three years in sealed packing kept dry, on pallets and out of direct sun. Chemical ageing is slow because the material is already blown. 95/25 stores better than the softer grades because at 25 dmm the blocks stay firm enough that stack fusion is much less of a problem on a long sea leg.
What is the HS code for oxidized bitumen?
HS 2713.20, petroleum bitumen, which covers all oxidized and penetration grades. National tariffs add further digits, so confirm the full code with your customs broker. Gilsonite and other natural bitumen fall under a different heading.
What is the minimum order quantity?
One full 20′ container, roughly 22 to 25 MT depending on packing. Mixed grades in one shipment are accepted provided each grade reaches one full container. Loading is from Jebel Ali Port in Dubai or Iskenderun Port in Turkey, on FOB, CFR or CIF terms.
Can you supply against a tighter specification?
Yes. Where the reason for choosing 95/25 is climate rather than habit, it is worth contracting to a narrower softening point band — for example 94 to 98 °C — so the batch delivers the heat margin you are paying for. Say so at the enquiry stage, since it affects which production batch is allocated.
Related grades and technical pages
Adjacent grades: oxidized bitumen 85/25 for temperate markets, 105/35 for hot climates, 90/40 where more flexibility is needed, and 115/15 or 105/15 for industrial and pipe coating work. The complete list is on the oxidized bitumen grades page.
Where a compound needs additional hardness, gloss or a higher softening point than blown bitumen alone can deliver, gilsonite is frequently blended in — see gilsonite specification, gilsonite in paint and gilsonite in asphalt. For the difference between air-blown and naturally occurring hard bitumen, see natural bitumen.
Request a quotation for oxidized bitumen 95/25
Send us the quantity, packing, discharge port and the specification your contract names. Tell us the highest summer temperature at the installation market and we will confirm whether 95/25 is the right grade or whether 85/25 or 105/35 fits better. Batch certificate of analysis with every shipment, third-party inspection accepted at loading.
Dubai: No. 2305, Burlington Tower, Business Bay — +971 4 566 4998
Ankara: Karşıyaka District, 749 Street No. 30, Gölbaşı 06830 — +90 312 544 5481
Isfahan: Second Floor, Navab Complex, Navab Safavi St
