Fiber (FRP) & Steel Doors — Complete Guide
FRP (Fiber Reinforced Plastic / Polyester) doors and steel doors are specialised non-wood doors chosen for their superior security, fire-resistance, durability and weather resistance. They serve specific Indian construction needs — main entrance security, fire exits, industrial / commercial buildings, factory doors, hospital areas, server rooms, and weather-exposed locations.
These doors are governed by IS 4351 (Steel Doors & Windows), IS 3614 (Fire Check Doors & Windows), IS 277 (Galvanised Steel Sheets), IS 4998 (FRP Doors). Top brands: Godrej Security Doors, Tata Pravesh, Crompton Security, Sintex FRP, JK Doors, Welspun Steel Doors, Greenply Doors.
Types of Specialty Doors
| Door Type | Construction | Use |
|---|
| FRP / Fiberglass Door | Polyester resin + glass fibre over PU foam core | Bathroom, exterior, humid areas |
| Steel Security Door | Hot rolled steel frame + GI sheet skin | Main entrance security |
| GI Steel Door | Galvanised steel sheet skin + PU foam | Modern entrance doors |
| Fire Rated Steel Door | Steel skin + fire core (mineral wool / vermiculite) | Fire exits, stairwells |
| Stainless Steel Door | SS 304 / 316 grade | Premium / coastal |
| Aluminium Folding Door | Aluminium frame + panels | Industrial overhead doors |
| Roller Shutter Door | Galvanised steel slats | Garage, shop, factory |
| Industrial Steel Door | Heavy duty steel frame | Factory, warehouse |
| Pressed Steel Door | Pressed sheet steel frame | Commercial / institutional |
| FRP Sandwich Door | FRP skin + foam core + FRP skin | Bathroom, kitchen, exterior |
| Composite (FRP + Steel) | FRP face + steel reinforcement | Security + waterproof |
FRP (Fiber Reinforced Polyester) Doors
What is FRP?
FRP doors are made of polyester resin reinforced with glass fibres, formed in a mould to create a hard composite shell, then filled with polyurethane foam (PUF) for insulation and structural rigidity. The result is a 100% waterproof, termite-proof, lightweight, low-maintenance door perfect for bathrooms, exterior doors, and humid coastal climates.
FRP Door Construction
- FRP Outer Skin (Face): 2–3 mm thick polyester + glass fibre laminate
- Core (Infill): Polyurethane foam (PUF, density 40–60 kg/m³) for insulation + strength
- Internal Reinforcement: Wood / FRP lock block, hinge blocks
- Edge: FRP edge or PVC trim
- Frame: FRP, GI steel, or aluminium frame
FRP Door Properties
| Property | Value |
|---|
| Density | FRP: 1500 kg/m³, with foam core: 400–600 kg/m³ |
| Tensile Strength (FRP) | 80 – 200 MPa |
| Flexural Strength | 120 – 250 MPa |
| Modulus of Elasticity | 8 – 15 GPa |
| Water Absorption | < 0.5% |
| Operating Temperature | −30 to +80 °C |
| Thermal Conductivity | 0.3 – 0.4 W/m.K (with PUF core) |
| Sound Reduction | ~25 dB |
| UV Resistance | Good (gel-coat surface) |
| Lifespan | 20 – 30 years |
| Weight (40 mm) | 20 – 30 kg |
Steel Doors
Types of Steel Doors
| Type | Construction | Use |
|---|
| MS (Mild Steel) Solid Door | Hot-rolled steel frame + plate | Industrial entrance |
| GI Sheet Door | 0.8–1.2 mm GI sheet on steel frame | Modern home entrance, security |
| Pressed Steel Door | Pressed sheet steel | Commercial / institutional |
| Steel Security Door | Reinforced steel + multi-point lock | Premium security |
| Fire Rated Steel Door | Mineral wool / vermiculite core in steel | Fire exits, stairwells |
| Cold Storage Door | Insulated steel | Cold rooms, freezers |
| Acoustic Steel Door | Steel + sound absorbing core | Studios, conference rooms |
| Bullet Resistant Door | Hardened steel + Kevlar | Banks, vaults, embassies |
| Stainless Steel Door | SS 304 / 316 grade | Premium, coastal, food industry |
| Rolling Shutter | Interlocked steel slats | Garage, shops |
| Sliding Steel Door | Track-mounted | Industrial, warehouse |
Steel Door Construction
- Frame: Hot-rolled / cold-rolled steel angle / channel
- Face Skin: 0.8–1.5 mm GI / pre-painted steel sheet
- Core:
- Hollow (no core) — lightweight
- Honeycomb cardboard — basic insulation
- Polyurethane foam (PUF) — thermal insulation
- Mineral wool — fire resistance
- Vermiculite board — fire rated
- Solid steel (security)
- Reinforcements: Lock plate, hinge plate
- Edge Profiles: PVC / aluminium / steel edge
- Surface Finish: Powder coated / painted / pre-painted
- Hardware: Multi-point lock, hinges, viewer, handle
Fire-Rated Doors
Fire-rated doors are designed to resist fire spread for a specified time (30, 60, 90, 120 minutes), providing crucial escape time and compartmentalisation.
| Rating | Time Holding Back Fire | Use |
|---|
| FD 30 (30 min) | 30 minutes | Apartment entry, hotel rooms |
| FD 60 (60 min) | 60 minutes | Stairwell access, lobby |
| FD 90 (90 min) | 90 minutes | Industrial, public buildings |
| FD 120 (120 min) | 120 minutes | Critical fire compartmentation |
| FD 180 (180 min) | 180 minutes | Very high risk areas |
Fire Door Features
- Steel frame & sheet skin (galvanised)
- Mineral wool / vermiculite / rock wool core
- Intumescent strip (expands with heat, seals gaps)
- Smoke seal (cold smoke seal)
- Self-closing hinges
- Fire-rated locks & hardware
- Glass vision panel (fire-rated glass, with wire mesh or Pyrostop)
- BIS / IS 3614 certification mark
- Door + frame system tested together
Top Indian Brands
| Brand | Products |
|---|
| Godrej Security Solutions | Godrej NXT, Defender, Spacewood Security Door |
| Tata Pravesh | Premium GI steel home doors |
| Sintex Industries | Sintex FRP Doors |
| Tata Steel (Door Division) | Tata Astrum Doors |
| JK Door / JK Iron Industries | JK Security Doors |
| Crompton Greaves Steel Doors | Crompton Doors |
| Welspun Group | Welspun Steel Doors |
| Greenply (Greenpanel) | FRP / Steel composite doors |
| Magnatech | Fire rated doors |
| Sushi Steel | Industrial steel doors |
| Steel Authority of India (SAIL) | Industrial steel doors |
| Action TESA | Action FRP & metal doors |
| Polytec Industries | FRP doors |
| Saint-Gobain (Sharon) | Sharon FRP |
| Asahi Doors | Premium metal / FRP |
FRP vs Steel vs Wood Doors
| Parameter | FRP Door | Steel Door | Wood Door |
|---|
| Material | Polyester + glass fibre | Steel + paint | Hardwood |
| Water Resistance | 100% | Excellent (with coating) | Limited |
| Termite Resistance | Excellent | Excellent | Treated |
| Fire Resistance | Limited (FR variants) | Excellent (mineral wool core) | Limited (FR treated) |
| Security | Moderate | Excellent (multi-point lock) | Moderate |
| Thermal Insulation | Good (PUF core) | Good (with PUF) | Excellent |
| Sound Insulation | ~25 dB | ~30 dB (with core) | ~30 dB |
| Weight | 20 – 30 kg | 30 – 60 kg | 30 – 50 kg |
| Premium Aesthetic | Moderate | Modern | Best (natural) |
| Customisation | Limited | Moderate | Excellent |
| Lifespan | 20 – 30 years | 30 – 50 years | 50 – 100 years (teak) |
| Maintenance | Very Low | Periodic painting | Periodic re-polish |
| Cost (Standard) | Rs 5,000 – 15,000 | Rs 8,000 – 35,000 | Rs 12,000 – 50,000 |
| Best For | Bathroom, exterior humid | Main entrance security | Premium / heritage |
Standard Sizes
| Application | Size (mm) |
|---|
| Main Entrance (Steel Security) | 2134 x 914 / 2438 x 1067 |
| Bedroom (FRP / Steel) | 2032 x 813 / 2134 x 813 |
| Bathroom (FRP) | 1981 x 686 / 1981 x 762 |
| Fire Exit (Steel Fire Rated) | 2032 x 813 / 2134 x 914 |
| Industrial / Garage (Steel) | Up to 6000 x 3000 (roller shutter) |
| Server Room (Steel + Acoustic) | 2032 x 813 |
| Cold Storage (Insulated Steel) | Up to 3000 x 2400 |
Steel Security Door Features (Premium)
- 1.0–1.5 mm GI steel sheet skin (both sides)
- Steel frame channel (50–75 mm)
- 3–5 multi-point lock points (top, middle, bottom)
- Hardened steel deadbolts (Rs 3+ thick)
- Anti-theft hinges (anti-lift pins)
- Wide-angle peephole (180° viewer)
- Polyurethane foam insulation core
- Powder coated finish (anti-rust)
- Optional electronic / biometric lock
- Anti-pry plate at lock area
- Dummy hinges (decoration only)
- Active & passive locking systems
- EN 1627 / RC2 / RC3 / RC4 burglary resistance certification
- Internal panic bar (emergency egress)
- Self-closing mechanism (optional)
Installation Process
FRP Door (Bathroom)
- Frame placement in wall opening
- Plumb & level check
- Fix frame with metal anchors / screws
- Silicone seal at wall junction
- Install FRP shutter on hinges
- Install lock + handle (SS 304)
- Final adjustment + test
Steel Security Door (Main Entrance)
- Receive pre-assembled door + frame
- Inspect for damage (factory tested)
- Wall opening preparation (square, plumb)
- Lift door + frame into opening (heavy — 60–100 kg)
- Level & plumb adjustment
- Anchor fixing (12–16 expansion bolts in concrete)
- Polyurethane foam gap fill
- Plaster patch / cover
- Install hardware (locks, viewer, handle)
- Test multi-point lock engagement
- Apply silicone exterior sealant
- Programme electronic / biometric lock (if applicable)
Fire-Rated Door
- Verify IS 3614 compliance certification
- Install door + frame as a tested system (do not mix manufacturers)
- Use only manufacturer-supplied hinges, locks, closers
- Intumescent strip on frame (must extend full height)
- Smoke seal installation
- Self-closing mechanism (essential for fire rating)
- Verify gap dimensions (3 mm sides, 6–8 mm bottom)
- Mortar / fire sealant gap fill (no PU foam)
- Install fire-rated lock + panic bar
- Inspection by fire department (commercial)
Advantages (FRP)
- 100% waterproof (zero swelling)
- Termite, rot, mould proof
- Lightweight (20–30 kg)
- Corrosion proof
- UV stable (with gel coat)
- Low maintenance (just wipe)
- Wide colour options
- Cost-effective for bathrooms
- Eco-friendly (recyclable)
- Available in wood-grain finish
- Easy to clean
- Long lifespan (20–30 years)
- Custom shapes possible
- Compatible with all hardware
Advantages (Steel)
- Best security (multi-point lock, hard penetration)
- Excellent fire resistance (with mineral wool core)
- Resistance to forced entry (FRP cannot match)
- Bullet resistant variants available
- Long lifespan (30–50 years)
- Anti-tamper hinges
- Heat-treated locks
- 30 / 60 / 90 / 120 min fire rating
- Insurance-approved (security doors)
- Smoke seals (fire safety)
- Cold storage / industrial use
- Bullet resistant available (banks)
- Aesthetic options (wood-grain GI / powder coat)
- Termite, rot proof
- BIS / EN certified
- Acoustic options
Disadvantages
FRP Doors
- Limited security (cannot match steel)
- Lower fire resistance (no mineral core)
- Aesthetic value lower than wood
- Surface damage difficult to repair
- Lower sound insulation than steel / wood
- Not suitable for main entrance security
- UV degradation possible (cheap variants)
- Cannot be sanded / refinished
- Synthetic feel
Steel Doors
- Higher cost than wood / FRP
- Heavy (60–100 kg installed)
- Cold to touch in winter
- Requires periodic painting (anti-rust)
- Industrial / institutional aesthetic
- Surface dents permanent
- Conducts sound (without core)
- Conducts heat (without core)
- Difficult on-site modification
- Specialised installation
- Salt-air corrosion in coastal areas
- Heavy frame requires strong wall
Where to Use
FRP Doors:
- Bathroom doors (premium)
- Kitchen doors (humid)
- Servant quarters / utility
- Coastal / humid coastal homes
- Marine / boat doors
- Outdoor pool houses
- Industrial sanitary doors
- Hospital wash areas
- Food processing (hygienic)
Steel Security Doors:
- Main entrance (premium homes)
- Apartment main door
- Vault & safe rooms
- Bank / financial institutions
- Jewellery shops
- Server rooms
- Government / defence offices
- Embassies, high-value premises
- Industrial / warehouse main
Fire Rated Doors:
- Apartment main door (most cities require FD30)
- Hotel room doors
- Stairwell access doors
- Hospital corridors
- Industrial buildings
- School / college fire exits
- Mall corridors
- Multi-storey commercial
- Server / electrical rooms
- Boiler rooms, kitchens (commercial)
Cost (Approximate, Indian Market)
FRP Doors
| Type / Size | Cost (Rs) |
|---|
| Basic FRP Bathroom Door | 2,500 – 5,500 |
| Premium FRP Door (Wood Grain) | 4,500 – 9,500 |
| FRP Composite Door (Bedroom) | 6,500 – 14,000 |
| FRP Designer Door (CNC patterns) | 10,000 – 22,000 |
| FRP Frame (Chowkat) | 2,500 – 6,500 |
Steel Doors
| Type / Size | Cost (Rs) |
|---|
| Basic GI Steel Door (no security) | 5,500 – 12,000 |
| Pressed Steel Door (Commercial) | 6,500 – 14,000 |
| Tata Pravesh Standard Steel Door | 15,000 – 28,000 |
| Godrej Security Door (Standard) | 22,000 – 45,000 |
| Godrej / Tata Premium Security Door | 35,000 – 85,000 |
| Bullet Resistant Steel Door | 1,50,000 – 5,00,000+ |
| Stainless Steel Door (SS304) | 25,000 – 70,000 |
| Heavy Industrial Steel Door | 15,000 – 35,000 |
| Roller Shutter (per sqft) | 180 – 450 |
Fire Rated Doors
| Rating / Size | Cost (Rs) |
|---|
| FD 30 (30 min) Steel | 12,000 – 22,000 |
| FD 60 (60 min) Steel | 18,000 – 32,000 |
| FD 90 (90 min) Steel | 25,000 – 45,000 |
| FD 120 (120 min) Steel | 35,000 – 65,000 |
| FD 30/60 Wood Composite | 15,000 – 35,000 |
| Glass Vision Panel (FR glass) | +8,000 – 15,000 |
| Panic Bar Hardware | +4,500 – 12,000 |
| Closer / Self-Closing Mechanism | +2,500 – 8,000 |
Tests on FRP / Steel Doors
- Dimensional Tolerance Test
- Door Strength Test — IS 4020 / EN 1192
- Hinge Pull-Out Test
- Slamming Test (100,000 cycles) — IS 4020 Part 9
- Edge Loading — IS 4020 Part 12
- Impact Resistance (Hard Body)
- Water Tightness (FRP)
- Termite Resistance — IS 4873
- Fire Resistance Test — IS 3614 Part 2 / EN 1634-1 (30/60/90/120 min)
- Smoke Permeability — EN 1634-3
- Burglar Resistance — EN 1627 (RC1 to RC6)
- Bullet Resistance — EN 1063 (BR1 to BR7)
- Salt Spray Test (Steel) — ASTM B117
- Powder Coating Adhesion — ISO 2409
- UV Weathering (FRP) — ASTM G155
- Lock Cycle Test (200,000 cycles)
- Forced Entry Resistance
- Heat Transmission
- Acoustic Performance — EN ISO 717
Best Practices
- For main entrance security, use steel security door (Godrej / Tata Pravesh)
- For bathroom, FRP is excellent (waterproof, termite-proof)
- For apartments, FD30 fire rated steel door is mandatory in many cities
- For fire exits, use only certified IS 3614 doors
- Door + frame must be tested as a system
- For coastal areas, use SS hardware or salt-treated steel
- Use multi-point lock minimum (3 lock points)
- Install peephole at 1500–1600 mm height
- Use anti-burglary hinges (anti-lift, mushroom heads)
- For server / electrical rooms, use FD60 minimum
- Fire door must have self-closing mechanism
- Fire door requires intumescent strip + cold smoke seal
- Use only certified hardware with fire doors (do not mix)
- Do not modify fire doors on site (voids certification)
- Inspect / test multi-point lock annually
- Lubricate hinges and locks twice yearly
- Repaint steel doors every 5–7 years (exterior)
- FRP doors: simple wipe-down maintenance
- Steel doors: SS hardware essential in coastal
- Get BIS / IS 3614 / EN 1634 certificates from supplier
Applicable Standards
| Standard | Description |
|---|
| IS 4351 | Steel Doors for Buildings — Specification |
| IS 1038 | Steel Doors, Windows & Ventilators — Specification |
| IS 277 | Galvanized Steel Sheets (Plain & Corrugated) |
| IS 3614 (Part 1) | Fire Check Doors — Plate, Metal Covered Doors |
| IS 3614 (Part 2) | Fire Check Doors — Fire Resistance Test |
| IS 4998 | FRP Doors — Specification (related) |
| IS 4020 | Methods of Test for Wooden Flush Doors (applied to FRP) |
| IS 4873 | Termite Resistance Test for Doors |
| EN 1634-1 | Fire Resistance Tests for Door Assemblies |
| EN 1634-3 | Smoke Control Tests for Doors |
| EN 1627 / 1628 / 1629 / 1630 | Burglar Resistance Classes (RC1 to RC6) |
| EN 1063 | Bullet Resistance Classes (BR1 to BR7) |
| EN 1192 | Doors — Strength Requirements |
| EN 14351-2 | Internal Pedestrian Doorsets — CE Marking |
| UL 10C | Fire Tests of Door Assemblies (USA) |
| NFPA 80 / 252 | USA Fire Door Standards |
| NBC 2016 | National Building Code — Fire Safety |
Conclusion
FRP and steel doors serve specialised but critical roles in modern Indian construction. While wooden flush doors dominate interior bedrooms, FRP rules waterproof bathroom applications and steel dominates security & fire safety requirements.
Recommendations:
- Bathroom / Wet area: FRP door with FRP / SS frame (Rs 2,500–5,500) — or WPC door
- Main entrance (security): Steel security door (Godrej / Tata Pravesh, Rs 22,000–85,000)
- Apartment main door: FD30 fire rated steel door (Rs 12,000–25,000)
- Apartment building fire exit: FD60 / FD90 steel (Rs 18,000–45,000)
- Industrial main: Heavy duty steel door (Rs 15,000–35,000)
- Garage / Workshop: Roller shutter (Rs 180–450/sqft)
- Bank / Vault / Embassy: Bullet resistant steel (Rs 1.5–5+ lakh)
- Hospital / Clean room: Steel hygienic / FRP sanitary
- Cold storage: Insulated steel door
- Premium home aesthetic: Solid teak wood + steel security ahead
- Coastal / humid: FRP or SS 316 steel
For internal doors, see flush doors or WPC / PVC doors; for premium wooden doors, see teak / sheesham wood; for windows, see UPVC or aluminium sliding.