What is a Flush Door?

Flush door construction:

1. Stile & Rail Frame: Vertical stiles + horizontal rails (top, bottom, intermediate lock rail) of solid hardwood (75–100 mm wide)
2. Core / Infill: Various options (solid block, particle board, plywood strips, hollow honeycomb)
3. Lipping: 4 edges sealed with hardwood lipping (10–25 mm)
4. Face Skin: 3–4 mm thick commercial / BWR / BWP plywood, MDF, or HDF glued both sides
5. Decorative Finish: Laminate, veneer, paint, or membrane applied post-manufacture

Types of Flush Doors

By Core Construction

Type	Core Material	Use
Solid Core Flush Door (Most Common)	Hardwood block / particle board / MDF infill	Bedroom, office, all interior
Hollow Core Flush Door	Cardboard honeycomb / waffle infill	Cheap residential, light use
Particle Board Core Flush Door	Compressed particle board	Budget interior
Block Board Core Flush Door	Wood-strip block board	Stable mid-premium
Lock-Block Flush Door	Hollow core + solid wood block at lock	Budget with lock support
MDF Core Flush Door	Solid MDF (no frame)	Painted doors
Glazed Flush Door	With glass insert	Office partitions, kitchen
Fire Rated Flush Door	Mineral / fire-board core	Fire exits, commercial

By Face Skin / Grade

Grade	Face Skin	Use
MR Grade Flush Door	MR Plywood / MDF facings	Bedroom interior dry
BWR Grade Flush Door	BWR Plywood facings	Internal premium
BWP / Marine Flush Door	BWP Plywood facings	Bathroom, kitchen, wet areas
FR (Fire Rated) Flush Door	Fire-retardant ply + core	Fire safety locations

Solid Core vs Hollow Core

Parameter	Solid Core Flush Door	Hollow Core Flush Door
Core Material	Hardwood / particle board / MDF block infill	Cardboard honeycomb / open framework
Weight (40 mm)	25–35 kg	15–20 kg
Sound Insulation	Good (~30 dB)	Poor (~18–22 dB)
Strength	Excellent	Limited
Hinge / Lock Holding	Excellent (anywhere)	Only at lock-block, frame
Thermal Insulation	Good	Limited
Fire Resistance	Good (30 min)	Poor (10 min)
Security	Better	Easily breached
Premium Feel	Yes (solid sound)	No (hollow sound)
Cost	Higher (Rs 3,500–12,000)	Lower (Rs 1,800–4,500)
Lifespan	20–35 years	10–15 years
Best For	Bedroom, office, premium use	Budget, light traffic, closets

Standard Sizes (IS 2202)

Application	Standard Size (mm)	Imperial (ft)
Single Bath / Toilet	1981 x 686	6.5 x 2.25
Bathroom Standard	1981 x 762	6.5 x 2.5
Bedroom Single	2032 x 813	6.75 x 2.75
Bedroom Standard	2134 x 813	7 x 2.75
Main Door (Single)	2134 x 914 / 2438 x 1067	7 x 3 / 8 x 3.5
Kitchen / Utility	2032 x 762 / 2032 x 813	6.75 x 2.5 / 6.75 x 2.75
Office Cabin	2032 x 813 / 2134 x 914	6.75 x 2.75 / 7 x 3
Wardrobe Shutter	2032 x 457 / 2032 x 610	6.75 x 1.5 / 6.75 x 2

Standard Thicknesses

• 30 mm — Bathroom / very light internal
• 32 mm — Light internal
• 35 mm — Light internal (cheap residential)
• 40 mm — Standard interior (MOST COMMON)
• 45 mm — Heavy interior, kitchen
• 50 mm — Main door, premium
• 55–60 mm — Fire-rated, security doors

Physical Properties (IS 2202)

Test	Requirement
Dimensional Tolerance (Length)	± 5 mm
Dimensional Tolerance (Width)	± 2 mm
Thickness Tolerance	± 1 mm
Squareness (Diagonal)	± 1 mm
Local Planeness Tolerance	± 0.5 mm in 300 mm
General Flatness Tolerance	± 6 mm in 2 m
End Immersion Test (BWP)	No delamination after 72 hr boil
Knife Test (Surface Soundness)	No splitting / loose facing
Glue Adhesion (Face to Core)	> 1 N/mm (BWR/BWP)
Screw Withdrawal (Face)	> 1500 N
Screw Withdrawal (Edge)	> 1000 N
Edge Loading	1 kN over 200 mm length (no failure)
Shock Resistance Test	Drop 5 kg ball from 250 mm height (no damage)
Buckling Test	Max bow 1% of length
Slamming Test	100,000 cycles (no damage)
Hinge Pull Out	> 1200 N
Fire Resistance (FR variant)	30 / 60 / 90 / 120 min (IS 3614)

Top Indian Brands & Products

Brand	Top Products
Centuryply	Sainik Flush Door, ArchitectPly Flush, Club Prime Flush
Greenply Industries	Green Flush, Green Doors
Greenpanel	Green Flush Doors
Duroply	Duro Forever Flush, Duro Aqua Flush
Sharon Plywood (Saint-Gobain)	Sharon Sentinel Flush, Sharon Premier Flush
Kitply	Kitply Marine Flush, Kitply Premier Flush
Action TESA	Action TESA Flush Door
Mahalaxmi Plywood	Mahalaxmi Flush Door
Archid Plywood	Archid Gold Flush, Archid Silver
Sarda Plywood	Sarda Star Flush, Sarda Premier Flush
Mayur Ply	Mayur Flush Doors
National Plywood	National Flush
National Door (Premium)	National Designer Doors

Surface Finishes & Customisation

Plain Flush Door

Unfinished commercial plywood face. Requires laminate, paint, or veneer.

Pre-Laminated Flush Door

Decorative laminate (0.7–1 mm) pre-glued at factory. 1000+ colours and wood-grain finishes. Rs 1,500–3,500 premium over plain.

Veneered Flush Door

Natural wood veneer (0.5–3 mm) face. Polishable. Premium aesthetic.

Painted Flush Door

PU lacquer / melamine paint applied. Solid colours or wood-stain effect.

Membrane Door

PVC membrane vacuum-formed over MDF face. Replicates panelled door look.

CNC Routed Designer Door

CNC patterns cut into MDF face. Modern designer look.

Glazed Flush Door

Cut-out for glass insert. Common in kitchen / office cabin doors.

Sliding / Pocket Flush Door

Mounted on top rail for sliding action. Space-saving.

Where to Use Flush Doors

Best For:

• Bedrooms (most popular use, BWR grade)
• Office cabins, conference rooms
• Hotel rooms (premium grade)
• Schools, colleges, hostels
• Hospitals, clinics (FR grade for safety)
• Internal partitions
• Apartment internal doors
• Cinema, auditorium (acoustic with FR)
• Library, study rooms
• Kitchen doors (BWP grade only)
• Wardrobe shutters (cheaper hollow core OK)
• Storage rooms, wardrobes

Avoid For:

• Bathroom doors (use WPC doors instead)
• Main entrance / security doors (use solid wood / steel)
• External / weather exposed (use steel / FRP)
• Heritage / luxury homes (use solid teak)

Installation Process

1. Frame (Chowkat) Check: Frame fixed in wall opening, plumb, level, square
2. Door Acclimatisation: Allow 24 hr in installation environment
3. Trim to Size: Plane / cut to fit frame opening (3 mm gap on sides, 8 mm bottom)
4. Edge Sealing: Apply sealer / primer to all cut edges (especially BWP)
5. Mark Hinge Positions: Top hinge 150 mm from top, bottom 250 mm from bottom, middle at centre
6. Mortise Hinge Recesses: Rout / chisel matching recesses on door & frame
7. Hinge Fitting: Fix 4″ SS / brass hinges with appropriate screws (25 mm long, 8 # gauge)
8. Hang Door: Mount, verify smooth swing 0°–180°
9. Mark Lock Position: Standard 950–1000 mm from floor
10. Lock Cutout: Use lock template for mortise + face plate cuts
11. Lock Installation: Mount lock body, latch plate, strike plate
12. Door Stopper: Wall / floor mounted stopper to prevent damage
13. Final Adjustment: Verify gap uniformity, lock alignment, hinge tightness
14. Door Handle: Install handle / pulls
15. Sealant: Silicone at frame-wall junction
16. Architrave: Install decorative trim (optional)
17. Finishing: Polish, paint, or laminate (if not pre-finished)

Quality Check & Buying Guide

Check	What to Look For
ISI Mark	BIS-licensed brand stamp with IS 2202
Brand Hologram	Tamper-proof hologram
Edge Stamp	Brand name printed on edge
Weight Test	Solid core: 25–35 kg, Hollow: 15–20 kg (40 mm bedroom door)
Sound Test	Tap on door — solid sound = solid core, hollow = hollow core
Surface Inspection	Smooth, no dents, no peeling laminate
Edge Inspection	Lipping clean, no gaps, no splits
Squareness	Diagonal lengths should match (± 2 mm)
Flatness	No visible bow or warp
Grade Specification	MR / BWR / BWP printed clearly
Warranty	10–25 years (BWP top brands)
Burn Test (Sample)	BWP / BWR — black phenolic smoke; MR — white smoke

Advantages

• Smooth flat surface (perfect for laminate / paint)
• Stable dimensions (less warp than panel doors)
• Modern minimalist aesthetic
• Wide finish options (laminate / veneer / paint / membrane)
• Available in many grades (MR to BWP)
• Standard sizes (mass-produced, affordable)
• Fire-retardant variants for safety
• Sound-dampening (solid core)
• Termite-treated wood frame
• 20–35 year lifespan (BWP grade)
• Compatible with all door hardware
• Easier to repair than wood / glass panel doors
• Better insulation than hollow PVC
• Premium look at moderate cost (Rs 4,000–12,000)
• BIS / ISO certified manufacturing

Disadvantages

• Hollow core has poor sound insulation
• Inferior brands warp / delaminate
• Damage to face skin difficult to repair
• Cheap MR grade swells in moisture
• Counterfeit / fake ISI doors common
• Less character than solid wood / panel doors
• Cannot be easily customised (sized)
• Internal block damage detection difficult
• Lock-block area in hollow doors limited
• Glue adhesive can fail over decades
• Less aesthetic than premium solid wood / panel
• BWP grade adds significant cost
• Formaldehyde emission (cheap MR grade UF)

Cost (Approximate, Indian Market — 40 mm Standard)

Door Type / Grade	Cost (Rs)
Hollow Core Flush Door (MR, 32 mm bathroom)	1,800 – 3,200
Solid Core Flush Door (MR, 40 mm bedroom)	3,500 – 5,500
Solid Core Flush Door (BWR, 40 mm)	4,500 – 7,500
Solid Core Flush Door (BWP / Marine, 40 mm)	6,500 – 11,000
Pre-Laminated Flush Door (BWR, 40 mm)	6,000 – 9,500
Pre-Laminated Flush Door (BWP, 40 mm)	8,500 – 14,000
Veneered Flush Door (BWR, with polish)	9,500 – 16,000
Veneered Flush Door (BWP, premium)	13,000 – 22,000
Membrane Door (Designer)	5,500 – 11,000
CNC Designer Flush Door	11,000 – 22,000
Fire Rated Flush Door (30 min)	9,000 – 18,000
Fire Rated Flush Door (60 / 90 min)	15,000 – 35,000
Glazed Flush Door	7,500 – 16,000
Hardware Set (Hinges + Lock + Handle)	1,200 – 4,500
Installation Labour	800 – 1,500 per door
Door Frame (Chowkat, hardwood)	2,500 – 6,500
Complete Bedroom Door (40 mm BWR)	Rs 8,000 – 15,000 all in

Tests on Flush Doors (IS 4020)

• Dimensional Tolerance — IS 4020 Part 2
• Squareness Test
• General Planeness — IS 4020 Part 4
• Local Planeness
• End Immersion Test (Water 72 hr) — IS 4020 Part 7
• Knife Test (Surface Soundness) — IS 4020 Part 11
• Glue Adhesion Test — IS 4020 Part 13
• Slamming Test (100,000 cycles) — IS 4020 Part 9
• Buckling Test — IS 4020 Part 10
• Edge Loading Test — IS 4020 Part 12
• Impact Indentation Test — IS 4020 Part 8
• Screw Withdrawal — IS 4020 Part 18
• Hinge Pull Out
• Loading / Soft Body Impact Test
• Fire Resistance — IS 3614 / EN 1634-1
• Formaldehyde Emission — EN 717

Best Practices

• For bedrooms / dry interior, BWR grade is sufficient
• For kitchens / semi-wet areas, use BWP grade flush door
• For bathrooms, use WPC doors instead (not flush)
• Choose solid core (not hollow) for bedrooms
• Insist on ISI-marked, IS 2202 compliant doors
• Buy from authorised dealers of top brands
• Use 4″ SS hinges (3 per door minimum)
• Maintain 3 mm side gap, 8 mm floor gap
• Apply edge sealant on all 4 sides
• Use door stopper to prevent wall damage
• Acclimatise door 24 hr in installation room
• For premium aesthetic, choose veneer + polish
• For modular budget, choose pre-laminated
• For high-fire-risk areas, choose FR-rated doors
• Match frame grade with shutter grade
• Use mortise locks (not surface-mounted)
• Polish / paint within 30 days of installation
• Keep manufacturer warranty card
• Avoid cheap MR grade for any door > bedroom use

Applicable Standards

Standard	Description
IS 2202 (Part 1)	Wooden Flush Door Shutters (Solid Core) — Specification
IS 2202 (Part 2)	Wooden Flush Door Shutters (Hollow Core) — Specification
IS 4020 (Parts 1–18)	Methods of Tests for Wooden Flush Doors
IS 303	Plywood (used for door face)
IS 710	Marine Plywood (BWP face for wet area doors)
IS 4990	Plywood for Concrete Shuttering
IS 1659	Block Boards (for block board core)
IS 3097	Veneered Decorative Plywood
IS 5509	Fire Retardant Plywood
IS 3614 (Part 2)	Fire Tests for Doors
EN 1634-1	Fire Resistance Tests for Doors
EN 1192	Doors — Strength Requirements
EN 1530	Door Leaves — Flatness
EN 12219	Climatic Influences on Doors
EN 717	Formaldehyde Emission

Conclusion

Flush doors are the modern standard for interior doors in Indian construction. With solid core BWR / BWP grades, they offer 20–35 year lifespan, stability, sound insulation and wide finish options at Rs 4,500–15,000 per door — far below custom solid wood (Rs 12,000–35,000).

Recommendations:

• Bedroom door: BWR Grade, Solid Core, 40 mm, Pre-Laminated or Veneered
• Kitchen door: BWP Grade, Solid Core, 40 mm
• Bathroom door: Use WPC doors (not flush)
• Office cabin: BWR Grade, Veneered or Glazed
• Main entrance: Solid teak / sheesham wood, or FRP / steel door
• Fire exit / commercial: FR Grade flush door (30/60/90 min)
• Wardrobe shutter: Hollow core or pre-laminated MDF
• Hostel / school: BWR solid core, simple laminate

Always verify ISI mark, brand authenticity, and choose grade appropriate to the room. For windows, see UPVC windows or aluminium sliding windows; for the base panel materials, see plywood and MDF / HDF.