Bitumen / Asphalt Shingles — Complete Guide
Bitumen Shingles (also called Asphalt Shingles or Asphaltic Shingles) are flexible composite roofing tiles made of a fibreglass or organic mat impregnated with asphalt and finished with coloured ceramic-coated granules. They are North America’s most popular residential roofing material (covering 70%+ of US homes) and are rapidly gaining acceptance in India for sloped residential, villa, resort and farmhouse roofs.
Asphalt shingles provide a premium aesthetic look at moderate cost, with 25–50 year warranties, excellent weather protection, and easy installation by trained workers. They conform to ASTM D3462 (Fibreglass Shingles), ASTM D225 (Organic), UL 790, ASTM E108 fire ratings.
What are Bitumen Shingles?
An asphalt shingle is a multi-layer composite roof tile, typically 1000 x 333 mm in size, with this structure (top to bottom):
- Coloured Ceramic Granules — UV protection, fire resistance, colour
- Top Asphalt Coating — weather barrier
- Fibreglass / Organic Mat — reinforcement
- Bottom Asphalt Coating — waterproof barrier
- Self-Sealing Adhesive Strip — activated by sun heat after installation
- Sand / Talc Release Coating — prevents sticking during transport
Once installed, the sun’s heat activates the asphalt adhesive strip, fusing shingles together into a wind-resistant continuous waterproof membrane — rated for wind speeds up to 240 km/h on premium variants.
Types of Bitumen Shingles
| Type | Description | Lifespan |
|---|
| 3-Tab (Strip) Shingle | Single layer, 3 cut-outs per shingle — classic look | 15–25 yr |
| Architectural / Dimensional / Laminated | Multi-layer, 3D wood-shake or slate look | 25–40 yr |
| Luxury / Designer / Premium | Heavier multi-layer, oversized tabs | 40–50 yr |
| Solar Reflective / Cool Roof | Reflective granules, reduces heat gain | 25–40 yr |
| Impact-Resistant (Class IV) | Polymer-modified, hail-resistant | 25–40 yr |
| Algae-Resistant | Copper-granules prevent algae growth | 25–40 yr |
| Fibreglass Mat Shingle | Glass mat reinforcement, common | 20–40 yr |
| Organic / Felt Shingle | Cellulose felt mat, heavier, older type | 15–25 yr |
| SBS-Modified (Rubberised) | Synthetic rubber polymer in asphalt | 30–50 yr |
Standard Sizes
| Type | Size (mm) | Exposure (mm) | Weight (kg/m²) |
|---|
| 3-Tab Shingle | 1000 x 333 | 143 mm | 9 – 10 |
| Architectural / Laminated | 1000 x 333 (often 940 x 343) | 143 mm | 11 – 14 |
| Luxury / Designer | 915 x 457 | 200 mm | 15 – 20 |
| Ridge / Hip Shingle | 305 x 305 | 200 mm | 10 – 14 |
| Starter Strip | 1000 x 165 | NA | 8 – 10 |
Bundle coverage: ~3 m² per bundle (typical) | 1 square (US) = 100 sqft = 9.3 m²
Composition
| Layer | Material | Percentage / Function |
|---|
| Coloured Granules | Crushed ceramic / slate / colour-coated stone | 20%, UV protection, aesthetics |
| Top Asphalt | Air-blown bitumen (modified) | 30%, waterproofing |
| Mat / Carrier | Fibreglass or organic cellulose felt | 15%, reinforcement |
| Filler / Limestone | Powdered mineral filler | 10%, body |
| Bottom Asphalt | Air-blown bitumen | 15%, waterproof barrier |
| Self-Seal Adhesive | Polymer-modified asphalt strip | 5%, wind resistance |
| Release Sand | Quartz sand / talc | 5%, anti-stick |
Physical Properties
| Property | Value |
|---|
| Density | 1100 – 1400 kg/m³ |
| Roof Weight (3-tab) | 9 – 11 kg/m² |
| Roof Weight (Architectural) | 11 – 15 kg/m² |
| Tensile Strength | 200 – 350 N (longitudinal) |
| Tear Strength | 1500 – 2500 N |
| Wind Resistance | 120 – 240 km/h |
| Fire Rating (UL 790) | Class A (highest) for fibreglass |
| Impact Rating | UL 2218 Class 1 – 4 |
| Operating Temperature | −30 to +90 °C |
| UV Resistance | 25 – 50 years (per warranty class) |
| Sound Reduction | ~25 dB |
| Cold Flexibility | −10 °C (passes ASTM D3462) |
Roof Deck & Underlayment Required
| Element | Specification |
|---|
| Roof Pitch | 17° minimum (4:12), preferred 25°–45° |
| Plywood Deck | 12 mm BWP / marine plywood OR 15 mm OSB |
| RCC Deck | Smooth surface, primed with bitumen primer |
| Self-Adhesive Underlayment | Eaves, valleys (Ice & Water Shield) |
| Felt Underlayment | 15 lb / 30 lb roofing felt — entire roof |
| Drip Edge | GI / aluminium at eaves & rakes |
| Ice & Water Barrier | For valleys, eaves (cold climates only) |
| Ridge / Roof Vents | For attic ventilation |
| Flashings | GI / aluminium at penetrations |
| Fasteners | Galvanised roofing nails, 30 mm long, 12 mm head |
Step-by-Step Installation
- Slope Check: Confirm pitch ≥ 17° (4 in 12). For 9°–17°, use double underlayment.
- Roof Deck: Install 12 mm BWP plywood deck on rafters / RCC base
- Drip Edge: Fix metal drip edge at eaves and rakes
- Underlayment: Roll-out 30 lb roofing felt or self-adhesive membrane — lap 100 mm
- Ice / Water Shield: Self-adhesive bitumen membrane at valleys & eaves (cold zones)
- Chalk Line: Snap horizontal & vertical chalk lines for shingle alignment
- Starter Strip: Lay along eaves with adhesive facing down toward overhang
- First Course: Full shingles flush with starter
- Second Course: Offset 150 mm from first (random pattern)
- Nailing: 4 nails per 3-tab shingle (6 in high-wind zones), placed along nailing strip
- Valleys: Closed-cut, open metal or woven valley method
- Penetrations: Install pipe boots, chimney flashings with step-flashing
- Ridge Cap: Hip and ridge shingles fold over apex / hip lines
- Cleanup: Remove tarpaulin, debris, leftover nails (magnetic sweep)
- Inspection: Walk roof carefully, check seal-strip alignment
Tests on Bitumen Shingles
- Tensile Strength & Elongation — ASTM D146
- Tear Strength — ASTM D1922 / D4073
- Pliability / Cold Flexibility — ASTM D3462
- Self-Sealing Adhesive Strength — ASTM D6381
- Wind Resistance — ASTM D3161 / D7158
- Fire Resistance — UL 790 / ASTM E108 (Class A / B / C)
- Impact Resistance — UL 2218 (Class 1 to 4)
- Granule Loss / Abrasion — ASTM D4977
- Heat Aging — ASTM D5147
- Algae Resistance — ASTM D3462 (copper-doped)
- UV / Weathering — ASTM G155 / G7141
- Water Penetration — ASTM D898
Bitumen Shingles vs Other Roofing — Comparison
| Parameter | Bitumen Shingles | Mangalore Tile | GI Sheet |
|---|
| Weight | 9 – 15 kg/m² | 60 kg/m² | 4 – 8 kg/m² |
| Lifespan | 25 – 50 years | 40 – 60 years | 15 – 40 years |
| Pitch | 17° – 60° | 22° minimum | 5° minimum |
| Wind Resistance | Up to 240 km/h | ~150 km/h | ~200 km/h |
| Fire Resistance | Class A (highest) | Excellent | Good |
| Insulation | Moderate | Excellent | Poor |
| Maintenance | Low | Periodic cleaning | Moderate |
| Aesthetics | Premium look | Heritage | Industrial |
| Cost (Rs/sqft, all-in) | 200 – 500 | 100 – 180 | 120 – 250 |
| DIY Possible | Yes (trained) | Difficult | Difficult |
Uses of Bitumen Shingles
- Residential homes (villas, bungalows, farmhouses)
- Resorts, hotels, eco-tourism cottages
- Hill-station cottages and chalets
- Garden gazebos, pergolas, gazebos
- Garages, storage sheds
- Heritage restoration / renovation
- Townhouse / row-house roofs
- Cabanas, pool houses, guest cottages
- Doghouses, playhouses, treehouses
- Commercial buildings with sloped roofs
- Replacement for old clay / metal tile roofs
- Renovation of existing low-pitch RCC slabs
Advantages
- Affordable premium look — less than slate or wood shake
- Easy installation — trained roofer can do 50 m²/day
- Many colours, patterns, designer profiles available
- 25–50 year manufacturer warranty
- Excellent fire resistance (Class A)
- High wind resistance (up to 240 km/h)
- Self-sealing — activates with sun heat
- Lightweight — can be installed over existing roof in some cases
- Easy to repair — individual shingles replaceable
- Excellent sound dampening (rain noise reduced vs metal)
- Energy-efficient cool-roof variants reduce AC load
- Hail-resistant Class IV impact rated
- Algae-resistant (copper-granule variants)
- Works on both wood and RCC slab base
Disadvantages
- Cannot be installed on flat or very low pitch (< 17°)
- Higher cost than basic GI sheets
- Asphalt is petroleum-based (less eco-friendly)
- Heat absorption — warmer attics (use ridge ventilation)
- Granule loss possible after 15–20 years
- Wind-blown debris can lift unanchored shingles
- Limited recyclability (special facilities required)
- Quality varies by manufacturer — cheap brands may delaminate
- Skilled installation needed (or warranty void)
- Hot climate softens asphalt (use SBS-modified for Indian climate)
- Algae streaks possible in humid areas (use algae-resistant)
- Visible shingle pattern not preferred by some buyers
- Hailstorm damage above Class IV rating
- Cannot walk on roof in hot sun (damages granules)
Quantity Estimation
| Item | Per m² of roof |
|---|
| 3-tab Shingles | ~7 nos (3 m² / bundle, 21 shingles) |
| Architectural Shingles | ~7 nos (3.1 m² / bundle) |
| Underlayment Felt | 1.1 m² |
| Plywood Deck (12 mm) | 1.05 m² |
| Roofing Nails | ~30 nos |
| Ridge Cap Shingles | 3.5 nos per m run of ridge |
| Wastage allowance | 10 – 15% |
Cost (Approximate, Indian Market)
| Type | Rate |
|---|
| 3-Tab Shingle (basic) | Rs 80 – 150 / sqft |
| Architectural Shingle | Rs 130 – 250 / sqft |
| Designer / Luxury Shingle | Rs 220 – 400 / sqft |
| SBS-Modified Premium | Rs 250 – 500 / sqft |
| Underlayment Felt | Rs 8 – 20 / sqft |
| Ice & Water Shield Membrane | Rs 25 – 60 / sqft |
| Plywood Deck (12 mm BWP) | Rs 60 – 110 / sqft |
| Installation Labour | Rs 40 – 80 / sqft |
| Complete roof (incl. deck + shingles + labour) | Rs 200 – 500 / sqft |
Best Practices
- Use only IS / ASTM certified shingles (GAF, IKO, Owens Corning, CertainTeed, Tegola, Onduvilla)
- Maintain pitch ≥ 17° (4 in 12) for proper water shedding
- Always lay double underlayment in valleys, eaves
- Provide attic ventilation — ridge + soffit vents
- Use 4 nails per shingle (6 in high-wind zones)
- Place nails at specified nailing strip, never on tab
- Install on a hot sunny day for self-seal activation
- Never walk on hot shingles — granules will dislodge
- Use Class IV impact-resistant variant in hailstorm zones
- Use copper-granule algae-resistant variant in humid coastal areas
- Stagger shingle joints (offset 150–200 mm)
- Use proper flashing at all penetrations
- Get manufacturer warranty registration done within 30 days
- Clean gutters and roof annually before monsoon
Applicable Standards
| Standard | Description |
|---|
| ASTM D3462 | Asphalt Shingles Made from Glass Felt and Surfaced with Mineral Granules |
| ASTM D225 | Asphalt Shingles (Organic Felt) Surfaced with Mineral Granules |
| ASTM D7158 | Wind Resistance of Asphalt Shingles (Uplift / Mechanical) |
| ASTM D3161 | Wind Resistance of Asphalt Shingles (Fan-Induced) |
| ASTM E108 / UL 790 | Fire Tests of Roof Coverings |
| UL 2218 | Impact Resistance of Prepared Roof Covering Materials |
| ASTM G7141 | Solar Reflectance Index of Roofing Materials |
| ASTM D6381 | Wind-Lift Resistance of Mechanically Attached Bitumen Shingles |
| FM 4470 / FM 4474 | Factory Mutual Approval Standards |
Conclusion
Bitumen / asphalt shingles offer Indian homeowners a perfect middle path — premium aesthetics like slate or wood shake, durability of 25–50 years, easy DIY-friendly installation, excellent fire and wind resistance, and a wide variety of colours and profiles — all at moderate cost (Rs 200–500 per sqft).
They are ideal for villas, farmhouses, resorts, hill-station cottages and renovation projects where the heavy structural support needed by clay tiles is not available. For long-span industrial sheds, use GI sheets; for flat terrace roofs, use RCC slabs; for daylight skylights, combine with polycarbonate sheets; for energy generation, consider solar roof tiles.