Bitumen Carpet Tile Backing: Complete Technical Guide, Grades & Manufacturing Process
Bitumen carpet tile backing is one of the most established and widely used applications of oxidized bitumen in the flooring industry. The dense, stable, and cost-effective nature of oxidized bitumen makes it the preferred backing material for modular carpet tiles used in offices, hotels, retail spaces, healthcare facilities, and educational institutions worldwide.
The global carpet tiles market was valued at USD 4.53 billion in 2025 and is projected to reach USD 8.75 billion by 2035, growing at a 6.8% CAGR (Global Growth Insights, 2025). Commercial applications account for over 65% of total carpet tile demand, with offices, hospitality, and retail leading consumption. At the heart of every bitumen-backed carpet tile is oxidized bitumen — the material that provides dimensional stability, acoustic performance, moisture resistance, and the lay-flat characteristics that define a high-quality carpet tile.
In this complete guide, RAHA Bitumen’s technical team explains everything about bitumen carpet tile backing: the layer structure, manufacturing process, grade selection, performance properties, and why oxidized bitumen remains the dominant backing material in the global carpet tile industry.
Why Bitumen Is the Standard Backing Material for Carpet Tiles
Carpet tiles — also known as modular carpet or carpet squares — must meet demanding performance requirements that distinguish them from broadloom carpet. They must lie flat without curling, maintain precise dimensional stability, resist moisture from below, provide acoustic comfort, and withstand repeated cleaning and foot traffic for 10–15+ years. Oxidized bitumen meets all of these requirements better than most alternatives.
Key properties of oxidized bitumen for carpet tile backing:
- Dimensional stability: Hard oxidized bitumen grades with ring-and-ball softening points ≥ 90°C prevent edge curl and tile movement — even when tiles straddle warm underfloor HVAC grilles. Independent laboratory testing confirms compliance with EN 986 ≤ 0.2% dimensional stability limits (Centexbel).
- High density and mass: Bitumen’s density (1,050–1,200 kg/m³) adds significant weight per m² — critical for the “lay flat” characteristic that keeps tiles in position without adhesive on most commercial floors.
- Moisture resistance: The impermeable nature of oxidized bitumen creates a barrier against moisture rising from the subfloor — protecting the carpet face from mold, mildew, and delamination.
- Acoustic performance: The dense bitumen backing absorbs impact sound and reduces airborne noise transmission — a key specification requirement for offices, hotels, and educational facilities.
- Excellent adhesion to backing fabrics: Oxidized bitumen bonds strongly to secondary backing materials (nonwoven polyester, fiberglass scrim) — creating the laminated structure that gives carpet tiles their mechanical integrity.
- Thermoplastic processing: Oxidized bitumen can be heated, applied as a liquid, and cooled to a solid — enabling high-speed in-line manufacturing processes at commercial scale.
- Cost-effectiveness: Bitumen is dramatically less expensive than alternative backing systems (PVC plastisol, polyurethane) — enabling competitive carpet tile pricing while meeting all performance requirements.
Market fact: Bitumen-backed carpet tiles now capture roughly 80% of commercial soft-surface flooring specifications globally, underscoring their total-cost and performance advantages (Mordor Intelligence, 2025).
The Bitumen Carpet Tile Structure – Layer by Layer
A standard bitumen-backed carpet tile consists of five distinct layers, each serving a specific function. Understanding this structure is essential for selecting the right oxidized bitumen grade for each layer.
Layer 1: Face Fiber (Fibrous Wear Surface)
The visible top surface of the carpet tile — typically tufted, loop pile, or cut pile construction in nylon, polypropylene, or wool fibers. This layer provides the aesthetic, comfort, and wear performance of the tile.
Layer 2: Primary Backing
A woven or nonwoven polypropylene or polyester fabric that holds the face fiber tufts in place. The primary backing has a fibrous back surface that is the substrate for the bitumen precoat layers.
Layer 3: First Precoat Layer (Bitumen or Petroleum Resin)
A thin layer of hot melt bitumen or petroleum resin composition applied to the fibrous back surface of the primary backing. This layer:
- Locks the carpet tufts to the primary backing (tuft bind)
- Seals the fibrous back surface for adhesion of subsequent layers
- Provides the initial bond between the carpet material and the backing system
Application rate: Thin coating, typically 200–400 g/m²
Layer 4: Second Precoat Layer (Adhesive Bitumen Composition)
A hot melt bitumen composition containing an adhesive polymer — typically ethylene vinyl acetate (EVA) or similar flexible vinyl resin. This critical layer:
- Provides the adhesive bond between the carpet material and the main backing layer
- Must remain tacky at the lamination temperature to achieve a strong permanent bond
- Contains sufficient polymer content to ensure peel strength at the lamination interface
Layer 5: Main Backing Layer (Heavy Bitumen Compound)
The primary structural and performance layer — a thick application of rubber-modified oxidized bitumen compound applied to a secondary backing sheet. This is the most critical layer, directly determining:
- Dimensional stability and lay-flat performance
- Total tile weight and acoustic mass
- Moisture barrier performance
- Overall tile stiffness and handling properties
Application rate: 40 to 125 oz/yd² (1,350–4,230 g/m²), most typically 75–100 oz/yd² (2,540–3,390 g/m²) per US Patent 4,702,950
Layer 6: Secondary Backing Sheet
A nonwoven synthetic fabric — typically spunbond polyester or fiberglass scrim — laminated to the outside of the main bitumen backing layer. This layer:
- Provides the smooth, stable bottom surface of the finished tile
- Adds tensile strength and prevents tearing during handling and installation
- Controls overall tile dimensions and prevents bitumen bleed-through
Bitumen Carpet Tile Backing Manufacturing Process
Carpet tiles are manufactured using a continuous in-line hot melt process. Understanding the manufacturing process helps material buyers specify the correct oxidized bitumen grade for each production stage.
Step 1: Raw Material Preparation
- Oxidized bitumen is loaded into heated compound vessels and melted to 160–180°C
- Mineral fillers (calcium carbonate, barite) and rubber modifiers (SBS, SBR, or EVA) are added in the specified ratios
- The compound is mixed until homogeneous — verified by softening point and penetration testing
- Application temperature maintained at 180–220°C throughout production
Step 2: Secondary Backing Sheet Feed
- Secondary backing material (nonwoven polyester or fiberglass) is fed from a roll onto the production line
- The backing sheet travels continuously through the coating and lamination stations
Step 3: Main Backing Layer Application (Coating Station)
- Hot molten bitumen compound is applied to the secondary backing sheet using a knife-over-roll or slot die coater
- Coat weight is precisely controlled — target: 75–100 oz/yd² (2,540–3,390 g/m²)
- AI-driven line controls (now widely adopted in modern facilities) trim coat-weight standard deviation by up to 25%, saving approximately 1.2 kg of bitumen per 1,000 tiles (Petronaft, 2025)
- The freshly coated backing sheet remains hot and tacky as it enters the lamination station
Step 4: Carpet Material Preparation
- Simultaneously, the carpet material (face fiber + primary backing) is fed from a separate roll
- First precoat layer (thin bitumen or petroleum resin) is applied to the fibrous back surface
- Second precoat layer (adhesive bitumen + EVA) is applied over the first precoat while still hot
Step 5: Lamination
- The carpet material (with hot, tacky second precoat) and the coated secondary backing sheet are brought together and pressed between lamination rolls
- The hot tacky surfaces bond permanently under controlled pressure
- Lamination temperature, pressure, and speed are precisely controlled for consistent bond strength
- Result: a continuous laminated carpet structure with all layers permanently bonded
Step 6: Cooling
- The laminated carpet structure passes through a cooling section (chilled rolls or air cooling)
- Controlled cooling rate is important — too fast causes internal stress; too slow allows sagging
- The bitumen compound solidifies and achieves its final dimensional stability properties
Step 7: Cutting & Finishing
- The cooled laminated carpet is cut into tiles using precision die cutters or guillotine cutters
- Standard sizes: 50×50 cm (European standard), 18×18 inches (45.7×45.7 cm) (US standard), also 60×60 cm and custom sizes
- Tiles are stacked, inspected, and packaged
Step 8: Quality Control
- Dimensional stability: EN 986 test — maximum 0.2% change after heat/humidity cycling
- Lay flat: Tiles must lie flat without edge curl under standard test conditions
- Tuft bind: Force required to pull individual tufts — minimum per EN 1338
- Coat weight: Verified by sample weighing against specification
- Delamination resistance: Peel strength between carpet and backing layers
- Acoustic performance: Impact sound reduction (ΔLw) per ISO 10140
Best Oxidized Bitumen Grades for Carpet Tile Backing
Selecting the correct grade is the most critical material decision in carpet tile production. The grade must provide the right balance of softening point (for heat resistance and dimensional stability), penetration (for flexibility and processing), and compatibility with rubber modifiers.
| Grade | Softening Point | Penetration | Best Use in Carpet Tile |
|---|---|---|---|
| 115/15 | ~115°C | ~15 dmm | Main backing layer — standard global specification. High softening point prevents edge curl and flow under warm subfloors. Most widely used carpet tile grade worldwide |
| 105/35 | ~105°C | ~35 dmm | Main backing layer — slightly more flexible than 115/15. Used where better low-temperature flexibility is required or where higher rubber modifier content is specified |
| 95/25 | ~95°C | ~25 dmm | Precoat layers, adhesive layers, light-duty backing for residential carpet tiles |
| 85/25 | ~85°C | ~25 dmm | First precoat layer, petroleum resin blends, softer backing compositions for residential applications |
Primary carpet tile grade: 115/15
The high softening point (~115°C) is essential for preventing the backing from softening and flowing on warm floors or during storage. Independent research confirms oxidized bitumen grades with softening point ≥ 90°C prevent edge curl even in demanding installation conditions (Centexbel laboratory testing). Grade 115/15 exceeds this requirement with significant margin — making it the industry standard.
Technical Specifications – Oxidized Bitumen 115/15 for Carpet Tile Backing
| Property | Test Method | Unit | Specification |
|---|---|---|---|
| Specific Gravity @25/25°C | ASTM D70 | kg/m³ | 1.05 approx. |
| Penetration @25°C | ASTM D5 | mm/10 | 10–20 |
| Softening Point (R&B) | ASTM D36 | °C | 110–120 |
| Ductility @25°C | ASTM D113 | cm | 1.5 min |
| Loss on Heating | ASTM D6 | wt. % | 0.2 max |
| Flash Point | ASTM D92 | °C | 260 min |
| Solubility in CS₂ | ASTM D4 | wt. % | 99.5 min |
→ Download full TDS: Oxidized Bitumen 115/15 Technical Data Sheet
Bitumen Carpet Tile Backing vs. Alternative Backing Systems
| Backing System | Material Cost | Dimensional Stability | Acoustic Performance | Environmental Profile | Market Share |
|---|---|---|---|---|---|
| Oxidized Bitumen | ⭐ Lowest | ⭐ Excellent | Good | Good (recyclable) | ~50–60% |
| PVC Plastisol | Medium | Good | Good | Poor (chlorine, plasticizers) | ~20–25% |
| Polyurethane | High | Good | ⭐ Excellent | Medium | ~10–15% |
| Rubber (SBR) | Medium-High | Good | ⭐ Excellent | Good | ~5–10% |
LCA studies show bitumen-backed carpet tiles can deliver one-third lower Global Warming Potential than PVC-backed tiles — because bitumen avoids plasticizers and chlorine, enabling safer end-of-life incineration or asphalt paving recycling (Petronaft, 2025).
Performance Benefits of Bitumen Carpet Tile Backing
1. Acoustic Comfort
Bitumen carpet tile backing significantly reduces impact sound transmission (footsteps, chair movement) and absorbs airborne noise in commercial spaces. The combination of bitumen mass and the carpet face fiber creates a highly effective acoustic system — reducing impact sound by typically 20–35 dB compared to hard floor surfaces. This is a primary specification driver in offices, hotels, and educational facilities.
2. Air Quality & Indoor Environment
Bitumen carpet tiles trap airborne particles (dust, allergens) in the pile, reducing their circulation in the room air. Regular vacuuming removes these particles effectively. The bitumen backing itself is chemically stable and does not off-gas volatile organic compounds (VOCs) under normal service conditions — an important consideration for LEED and BREEAM building certifications.
3. Walking Comfort & Ergonomics
The cushioning effect of the carpet pile combined with the firm, stable bitumen backing provides better underfoot comfort than hard flooring — reducing fatigue for standing and walking occupants. This is a documented benefit in retail, healthcare, and industrial environments.
4. Easy Installation & Replacement
Individual tiles can be replaced when damaged or worn — without disrupting the entire floor installation. The dimensional stability of the bitumen backing ensures replacement tiles fit precisely with existing tiles.
5. Safety
Carpet tiles provide better slip resistance than hard flooring — particularly important in wet-prone areas and high-traffic commercial spaces. The bitumen backing contributes to overall tile stability on the floor.
Applications – Where Bitumen-Backed Carpet Tiles Are Used
Commercial Offices
The largest single market for bitumen-backed carpet tiles. Open-plan offices, meeting rooms, and reception areas specify carpet tiles for acoustic performance, design flexibility, and ease of maintenance under raised access floors. Commercial applications account for over 70% of total modular carpet tile demand globally (Market Growth Reports, 2025).
Hospitality (Hotels & Restaurants)
Hotel corridors, guest rooms, and function rooms are major consumers of bitumen-backed carpet tiles. The combination of acoustic performance, durability, and design flexibility makes them the preferred flooring for premium hospitality projects worldwide.
Healthcare Facilities
Hospitals, clinics, and care homes specify bitumen-backed carpet tiles for their acoustic comfort, reduced fatigue for staff, and ability to replace individual damaged tiles. Healthcare facilities represent a key growth segment — lifecycle cost analysis demonstrates modular carpet tiles provide superior financial value over 50-year service periods (Mordor Intelligence, 2025).
Educational Institutions
Schools, universities, and libraries benefit from the acoustic performance and comfort of bitumen-backed carpet tiles. Interface reported 13% global billing growth in the education segment in 2024 as deferred renovation projects materialized.
Retail Spaces
Retail stores and shopping centers use bitumen-backed carpet tiles for their combination of aesthetic flexibility, durability under heavy foot traffic, and easy replacement of damaged tiles in high-wear areas.
Industrial & Transportation
Exhibition halls, airport lounges, and large-scale event venues use bitumen-backed carpet tiles for their cost-effectiveness in covering large areas and ability to be easily removed and replaced after events.
Why Source Oxidized Bitumen for Carpet Tile Backing from RAHA Bitumen?
RAHA Bitumen (RABIT) supplies oxidized bitumen for carpet tile backing to manufacturers in over 100 countries. Our carpet tile-grade materials offer:
- Consistent softening point and penetration — critical for stable production line performance and consistent tile dimensional stability batch-to-batch
- Low volatile content — reduced odor and VOC emissions in finished tiles — important for indoor air quality specifications (LEED, BREEAM, GREENGUARD)
- Excellent polymer compatibility — blends uniformly with SBS, SBR, EVA, and other rubber modifiers used in carpet tile formulations
- Full documentation: TDS, MSDS, COA for every shipment
- Third-party testing: SGS and Bureau Veritas inspection available
- Multiple packaging: 25kg meltable polyamide bags (most convenient for production), kraft bags, 200L drums, bulk tanker
- Primary carpet tile grade: 115/15 — available ex-stock for fast delivery
- Also available: 85/25, 95/25, 105/35 for precoat and specialized applications
- Fast global delivery from Isfahan, Iran via Dubai, UAE hub
📞 Contact our carpet tile specialist team:
Dubai Office: +971 56 281 7292 (WhatsApp)
Email: info@rahabitumen.com
Frequently Asked Questions
What grade of bitumen is used for carpet tile backing?
Oxidized bitumen 115/15 is the standard grade used for the main backing layer of carpet tiles globally. Its softening point of ~115°C is essential for preventing edge curl and flow on warm floors or during storage. For precoat layers, softer grades (85/25, 95/25) are commonly used. Grade 105/35 is used where greater flexibility is required in the main backing compound.
How much bitumen is used per carpet tile?
The main backing layer is applied at 75–100 oz/yd² (2,540–3,390 g/m²) — the most critical coat weight specification in carpet tile production. A standard 50×50 cm carpet tile (0.25 m²) therefore contains approximately 630–850 grams of bitumen compound in the main backing layer alone, plus additional bitumen in the precoat layers.
Why is oxidized bitumen better than PVC for carpet tile backing?
Oxidized bitumen offers several advantages over PVC plastisol: significantly lower material cost, better dimensional stability at elevated temperatures, absence of plasticizers and chlorine (better environmental profile), compatibility with asphalt recycling at end-of-life, and lower Global Warming Potential. LCA studies show bitumen-backed carpet tiles can deliver one-third lower Global Warming Potential than PVC-backed alternatives.
What is the standard size of a bitumen-backed carpet tile?
The most common standard sizes are 50×50 cm (European and international standard) and 18×18 inches (45.7×45.7 cm) (US standard). Sizes of 60×60 cm are also widely produced. Custom sizes are available from most manufacturers. Standard tile thickness ranges from 6–10mm depending on pile height and backing weight.
How is dimensional stability achieved in bitumen carpet tiles?
Dimensional stability is achieved through the combination of: the high softening point of the oxidized bitumen compound (≥ 90°C, typically 110–120°C for grade 115/15), a fiberglass scrim or nonwoven polyester secondary backing that prevents thermal expansion, precise coat weight control during manufacturing, and controlled cooling during production. These factors together ensure compliance with EN 986 ≤ 0.2% dimensional change specification.
Can bitumen carpet tiles be recycled?
Yes. Bitumen-backed carpet tiles can be recycled at end of life through: face fiber separation and recycling (nylon, polypropylene), bitumen backing recycled as asphalt pavement modifier, or whole-tile incineration for energy recovery. The absence of chlorine and heavy-metal plasticizers (unlike PVC) makes bitumen-backed tiles a more environmentally acceptable end-of-life option. Several major carpet tile manufacturers now operate take-back and recycling programs for bitumen-backed products.
Summary – Bitumen Carpet Tile Backing at a Glance
| Primary Grade | Oxidized Bitumen 115/15 |
| Softening Point Required | ≥ 90°C (115°C for grade 115/15) |
| Main Backing Coat Weight | 75–100 oz/yd² (2,540–3,390 g/m²) |
| Standard Tile Size | 50×50 cm (EU), 18×18 inches (USA) |
| Key Performance | Dimensional stability ≤ 0.2% (EN 986), lay flat, acoustic mass |
| Market Size (2025) | USD 4.53 billion → USD 8.75 billion by 2035 |
| Commercial Share | >65% of total carpet tile demand |
| Bitumen Market Share | ~80% of commercial soft-surface flooring specifications |
| Standards | EN 986, ASTM D312, BS 4692 |
| Available From | RAHA Bitumen – Global Supplier |
Related Products & Pages:
→ Oxidized Bitumen 115/15 — primary carpet tile backing grade
→ Oxidized Bitumen 105/35 — flexible backing grade
→ Oxidized Bitumen 95/25 — precoat layer grade
→ Oxidized Bitumen 85/25 — first precoat layer
→ Oxidized Bitumen Sound Dampening Felt
→ Oxidized Bitumen for Roofing
→ Oxidized Bitumen for Waterproofing
→ All Oxidized Bitumen Grades
Page last updated: May 2025 | Published by RAHA Bitumen Co. (RABIT) | Dubai, UAE & Turkey Ankara
