Understanding Plasterboard Colour Codes and Standards
Walk onto any construction site in the UK and you’ll see stacks of plasterboard in different colours. These aren’t just for decoration—they’re a visual identification system that tells tradespeople exactly what they’re working with at a glance.
The colour-coding system is universal across British manufacturers like British Gypsum, Knauf, and Siniat. Here’s what each colour means:
| Board Colour | Type | Primary Use | British Standard |
|---|---|---|---|
| Ivory/White | Standard | General interior walls and ceilings | BS EN 520 |
| Green | Moisture-Resistant | Bathrooms, kitchens, utility rooms | BS EN 520 (H2 moisture rating) |
| Pink/Red | Fire-Rated | Fire compartments, escape routes | BS EN 520 (Type F) |
| Blue | Acoustic | Sound insulation between rooms | BS EN 520 + acoustic testing |
Understanding these distinctions isn’t just about passing your NVQ Level 2 Plastering exam—it’s about complying with Building Regulations and ensuring your work stands the test of time. Let’s break down each type in detail.
Standard Plasterboard (White/Ivory): The Workhorse
Standard plasterboard is what most people picture when they think of “drywall.” It’s the most economical option and perfectly adequate for the majority of interior applications where moisture, fire, or sound aren’t critical concerns.
Technical Specifications
Standard plasterboard consists of a gypsum core sandwiched between two layers of heavy paper. The most common thicknesses you’ll encounter are:
- 9.5mm: Walls on 400mm or 450mm centres (residential standard)
- 12.5mm: Walls on 600mm centres, ceilings on 400mm centres
- 15mm: Ceilings on 600mm centres, improved sound insulation
Sheet sizes are standardised at 2400mm x 1200mm for most applications, though you can get 2700mm and 3000mm lengths for high ceilings. Edge types include tapered edge (for jointing compound), square edge (for skim coating), and bevelled edge (for decorative applications).
Where to Use Standard Plasterboard
This is your go-to board for:
- Living rooms, bedrooms, and hallways
- Partition walls in dry environments
- Ceiling applications in rooms without moisture concerns
- Stud walls where fire rating isn’t required by Building Regs
As we explain in our guide on how to skim coat a wall, standard plasterboard provides an excellent substrate for a 2-3mm skim coat of finishing plaster. The paper facing has just the right amount of suction to allow proper adhesion without pulling moisture too quickly from the plaster.
Pricing and Availability
As of 2026, expect to pay approximately:
| Thickness | Price per Sheet (Trade) | Price per m² |
|---|---|---|
| 9.5mm | £6.50–£8.00 | £2.25–£2.75 |
| 12.5mm | £7.50–£9.50 | £2.60–£3.30 |
| 15mm | £10.00–£12.00 | £3.45–£4.15 |
Trade prices from suppliers like Travis Perkins and Jewson typically offer 20-30% discounts over retail pricing at B&Q or Wickes. Collection is cheaper than delivery, but for full-house refurbs, the £40-60 delivery charge is worth avoiding multiple trips.
Moisture-Resistant Plasterboard (Green): Protection for Wet Areas
Green plasterboard—sometimes called MR board or water-resistant plasterboard—is essential for any area exposed to high humidity. The green colour comes from additives in both the paper facing and the gypsum core that provide water resistance.
How Moisture Resistance Works
The key difference isn’t waterproofing (no plasterboard is truly waterproof), but moisture tolerance. MR board uses:
- Wax-impregnated paper facings that repel water droplets
- Silicone additives in the gypsum core to reduce water absorption
- Modified crystal structure that maintains integrity when damp
According to Building Regulations Approved Document C (Site preparation and resistance to contaminants and moisture), moisture-resistant board should be used in any room with a bath, shower, or persistent steam exposure.
Where Moisture-Resistant Board Is Required
Our experience on hundreds of bathroom renovations shows MR board is non-negotiable in:
- Bathrooms and shower rooms (especially around baths and showers)
- Kitchen splash zones behind sinks and hobs
- Utility rooms with washing machines and tumble dryers
- Swimming pool changing areas
- Any room with underfloor heating (floor slab moisture rises)
For detailed guidance on wet area plastering, see our comprehensive article on bathroom plastering and which plaster to use in wet areas.
Installation Differences
Fitting green board isn’t dramatically different from standard board, but there are some crucial considerations:
- Never skim over MR board in wet areas: Use tile backer board and direct tile instead
- Use moisture-resistant jointing compound: Standard compound can fail in humid conditions
- Leave a 2-3mm gap at floor level: Allows any water pooling to drain rather than wicking up into the board
- Prime with PVA diluted 3:1 or bonding agent: The wax coating can reduce suction, affecting plaster adhesion if you’re skimming walls outside splash zones
Current Pricing (2026)
Green board typically costs 15-25% more than standard board:
| Thickness | Price per Sheet | Premium vs Standard |
|---|---|---|
| 12.5mm | £9.00–£11.50 | +£1.50–£2.00 |
| 15mm | £12.50–£15.00 | +£2.50–£3.00 |
The extra cost is minimal compared to the risk of mould, delamination, or complete board failure requiring expensive remedial work down the line.
Fire-Rated Plasterboard (Pink/Red): Life-Safety Protection
Pink or red plasterboard contains glass fibre reinforcement and additional fire-retardant materials that give it exceptional fire resistance. This isn’t just a nice-to-have—it’s a legal requirement in many situations.
Understanding Fire Ratings
Fire-rated plasterboard is classified by how long it can withstand fire exposure before structural failure. The rating depends on:
- Board thickness
- Number of layers
- Fixing centres (closer studs = better performance)
- Frame construction (steel or timber)
Common fire ratings you’ll encounter:
| Configuration | Fire Rating | Typical Application |
|---|---|---|
| Single layer 12.5mm on steel studs | 30 minutes | Basic fire compartments |
| Single layer 15mm on steel studs | 60 minutes | Escape routes, residential floors |
| Double layer 12.5mm on steel studs | 90 minutes | Commercial compartments |
| Double layer 15mm on steel studs | 120 minutes | High-rise buildings, hospitals |
These ratings come from tested assemblies certified under Building Regulations Approved Document B (Fire safety). Using fire board without following the tested specification voids the certification.
Where Fire-Rated Board Is Mandatory
Building Control will require pink board in:
- Escape routes: Corridors, stairwells, lobbies in flats and HMOs
- Fire compartment walls: Between attached dwellings (semi-detached, terraced houses)
- Separating walls: Between flats in the same building
- Ceiling between floors: In two-storey homes (often requires double-layer)
- Garage-to-house walls: 30-minute minimum, typically 60-minute
- Loft conversions: As detailed in our loft conversion plastering guide, fire protection is critical for means of escape
Installation Considerations
Fire-rated plasterboard is heavier and more rigid than standard board due to the glass fibre content. Key points:
- Weight: 12.5mm fire board weighs approximately 11kg per m² vs 9kg for standard
- Fixing centres: Must not exceed 300mm on edges, 600mm in field (some specs require 400mm)
- Screw type: Use drywall screws minimum 32mm for single layer, 42mm for double layer
- Joint treatment: Some fire-rated systems require specific fire-rated jointing compounds
- Penetrations: Every service penetration (cables, pipes) must be properly fire-stopped with intumescent sealant
Pricing Structure
Fire board is the most expensive standard plasterboard type:
| Thickness | Price per Sheet | Premium vs Standard |
|---|---|---|
| 12.5mm | £11.00–£14.00 | +£3.50–£4.50 |
| 15mm | £14.00–£17.00 | +£4.00–£5.00 |
For a typical party wall between semi-detached houses (say 8m long x 2.4m high = 19.2m²), you’re looking at an extra £67-86 for fire board versus standard. Not using it could invalidate your buildings insurance and breach Building Regulations—making it the cheapest insurance policy you’ll ever buy.
Acoustic Plasterboard (Blue): Sound Insulation Solutions
Blue plasterboard—acoustic or soundbloc—has a higher density core (typically 950-1200 kg/m³ vs 680 kg/m³ for standard board) that improves sound insulation. While not mandated by Building Regs in most domestic situations, it’s increasingly popular for reducing noise transmission.
Understanding Sound Insulation Ratings
Sound insulation is measured in decibels (dB). Building Regulations Approved Document E (Resistance to the passage of sound) sets minimum requirements:
- Walls between dwellings: 45 dB DnT,w minimum
- Floors between dwellings: 45 dB DnT,w minimum
- New rooms in existing buildings: Generally exempt unless creating new dwelling
Acoustic plasterboard can improve sound insulation by 3-7 dB depending on wall construction. That might not sound like much, but it’s a noticeable reduction—every 10 dB reduction is perceived as approximately “half as loud” by human ears.
Where Acoustic Board Makes Sense
We recommend blue board for:
- Party walls between terraced houses: Even when fire board meets the legal minimum, acoustic board improves neighbour relations
- Media rooms and home cinemas: Reduces sound transmission to other rooms
- Bedrooms above living areas: Improves impact sound insulation when combined with acoustic hangers
- Home offices: Creates privacy for video calls and confidential conversations
- Stud walls between bedrooms: Particularly valued in HMOs and family homes with teenagers
For comprehensive guidance on sound control, see our detailed article on acoustic ceilings and sound control.
Installation Tips for Maximum Performance
Acoustic performance depends heavily on proper installation. Common mistakes that negate acoustic benefits:
- Back-to-back sockets: Sound travels through electrical boxes—stagger them or use acoustic putty pads
- Gaps around edges: Seal all perimeter gaps with acoustic sealant, not standard decorator’s caulk
- Rigid connections: Use acoustic hangers and resilient bars to break sound transmission paths
- Insufficient cavity insulation: Always fill cavities with acoustic mineral wool (not standard loft insulation)
- Poor door seals: The best acoustic wall is compromised by gaps under doors—fit drop seals
Cost vs Benefit Analysis
Acoustic board pricing in 2026:
| Thickness | Price per Sheet | Premium vs Standard |
|---|---|---|
| 12.5mm | £15.00–£19.00 | +£7.50–£9.50 |
| 15mm | £19.00–£24.00 | +£9.00–£12.00 |
For a standard bedroom partition (3m x 2.4m = 7.2m²), the additional cost is about £22-28 per side. Most homeowners who invest in it report it’s money well spent, particularly for master bedroom suites and home offices.
Specialist Plasterboard Types
Beyond the four main types, several specialist boards combine properties or target specific applications:
Duplex Board (Purple/Grey)
Combines fire and moisture resistance in a single board. Essential for:
- Commercial kitchen fire compartment walls
- Bathrooms in flats requiring 30-60 minute fire ratings
- Boiler rooms and plant rooms
Pricing: £17-22 per 12.5mm sheet (2026), making it cheaper than boarding twice with separate specialised sheets.
Impact-Resistant Board (Yellow)
Features a reinforced core that resists damage from knocks and impacts. Used in:
- School corridors and sports halls
- Hospital wards and care homes
- Retail changing rooms
- Domestic applications with young children or wheelchair users
Thermal Plasterboard
Plasterboard with insulation bonded to the back—typically PIR, EPS or phenolic foam. Our guide on insulated plaster board covers these products in depth. Common thicknesses range from 32mm (board + 20mm insulation) to 92mm (board + 75mm insulation).
This is increasingly popular for internal wall insulation to meet Building Regulations Part L (Conservation of fuel and power) without losing too much room space.
Choosing the Right Plasterboard: Decision Framework
With multiple board types available, here’s a practical decision tree based on 20+ years of professional experience:
Step 1: Check Legal Requirements
Start with Building Regulations—these are non-negotiable:
- Is this a fire compartment wall? → Fire-rated board required
- Is this a wet area per Document C? → Moisture-resistant board required
- Is this between separate dwellings? → Check Document E for acoustic requirements
Step 2: Assess Environmental Conditions
Even if not legally required, consider practical needs:
- Will this room have consistent high humidity? → Consider MR board
- Is the existing structure prone to moisture issues? → See our guide on rising damp signs and causes before boarding
Step 3: Consider Lifestyle Factors
Quality of life improvements worth paying for:
- Do you value peace and quiet? → Acoustic board for bedroom walls and home office partitions
- Do you have young children or pets? → Impact-resistant board in high-traffic areas
- Are you concerned about heating bills? → Thermal board for external walls
Step 4: Budget Reality Check
If budget is tight, prioritise in this order:
- Building Regs compliance (fire, moisture where required)
- Wet areas (always use MR board in bathrooms)
- Party walls (acoustic board improves neighbour relations)
- Everything else (standard board is perfectly adequate)
Installation Best Practices Across All Board Types
Regardless of which plasterboard type you choose, professional installation follows these universal principles:
Storage and Handling
- Store flat: Stack on level bearers at 400mm centres maximum
- Keep dry: Even MR board shouldn’t be stored in the rain—cover with tarpaulin
- Acclimatise: Bring boards into temperature-controlled spaces 24 hours before fixing
- Handle carefully: Damaged corners and edges compromise fire ratings
Fixing Standards
- Stud centres: 400mm for walls, 450mm for ceilings on 12.5mm board
- Screw spacing: 300mm on edges, 600mm in field (tighter for fire board)
- Screw depth: 0.5-1mm below surface—countersunk but not breaking paper
- Edge support: Every board edge must land on a stud—use noggings where needed
Jointing and Finishing
For detailed techniques on achieving a perfect finish, see our comprehensive guide on how to skim coat a wall. Key points:
- Use tapered-edge boards with jointing compound for a flush finish without skimming
- Use square-edge boards if skim coating the entire surface
- Apply scrim tape to all joints before first coat of compound
- Internal corners require paper tape, external corners need metal or plastic beading
Common Mistakes and How to Avoid Them
After hundreds of remedial jobs, these are the errors we see most frequently:
Using Standard Board in Wet Areas
The Problem: Standard board in bathrooms leads to paper delamination, mould growth, and eventual structural failure within 2-5 years.
The Fix: Always use green board in bathrooms, even areas not directly exposed to shower spray. Humidity affects the entire room.
Ignoring Fire Rating Requirements
The Problem: Building Control fails the inspection, requiring expensive rework. Worse, insurance may be invalid if there’s ever a fire.
The Fix: Confirm requirements in writing from Building Control before starting. Keep documentation of products used and installation photos.
Poor Acoustic Detailing
The Problem: Spending £200+ on acoustic board then leaving gaps, using rigid fixings, or installing back-to-back sockets that negate the benefits.
The Fix: Acoustic performance is a system, not a single product. Follow manufacturer’s full specifications including sealants, resilient bars, and cavity insulation.
Mixing Board Types Without Purpose
The Problem: Using whatever’s on the van, creating patchy performance and potential warranty issues.
The Fix: Plan the entire job before ordering materials. Many suppliers offer quantity discounts—ordering the right boards for the whole project often costs less than multiple partial deliveries.
Where to Buy Plasterboard in 2026
Trade suppliers typically offer better pricing and expert advice:
Trade Merchants
- Travis Perkins: Excellent trade accounts, good stock of all types
- Jewson: Strong on British Gypsum products, helpful technical support
- Selco: Trade-only, cash-and-carry prices, limited range but good basics
- Covers: Regional coverage, competitive pricing on bulk orders
Retail Options
- Wickes: 10% trade discount available, convenient locations, limited specialist boards
- B&Q: Good for DIYers, higher prices, reliable stock of standard and MR boards
- Screwfix: Limited plasterboard range but excellent for fixings and jointing materials
Environmental Considerations and Sustainability
With growing focus on sustainable construction, plasterboard manufacturing has evolved significantly. Modern boards from UK manufacturers typically contain:
- 95%+ recycled paper facings from post-consumer waste
- Synthetic gypsum from flue-gas desulphurisation in power stations
- Reduced transport emissions through regional manufacturing
British Gypsum operates a recycling scheme for offcuts and waste board—check their website for participating merchants. Knauf also offers take-back programmes for clean, uncontaminated board waste.
When demolishing, separate plasterboard from other waste. Clean board (no paint, no nails) can be recycled back into new board, reducing landfill impact and manufacturing energy.
Frequently Asked Questions
Can I use moisture-resistant plasterboard throughout my entire house?
You can, but it’s unnecessary and increases costs by 15-25% without meaningful benefits. Standard board performs perfectly well in dry environments like bedrooms and living rooms. The moisture resistance only matters where humidity is consistently elevated. That said, some builders use green board throughout ground floors as cheap insurance against rising damp issues—it’s not required, but provides peace of mind.
Do I need fire-rated plasterboard on my garage ceiling?
Yes, if your garage is attached to or underneath living spaces. Building Regulations Part B requires 30-minute fire resistance minimum between garages and habitable rooms, typically achieved with 15mm fire-rated plasterboard on the garage ceiling. This protects escape routes if vehicle fire occurs. Detached garages with no connection to the dwelling don’t require fire boarding.
Will acoustic plasterboard really make a noticeable difference to sound insulation?
On its own, acoustic board improves sound insulation by approximately 3-7 dB—a measurable improvement but not dramatic. The real benefits come when it’s part of a comprehensive acoustic system including: resilient bars or acoustic hangers to break vibration transmission, acoustic mineral wool in the cavity, proper sealing of all gaps, and mass (double-layer boarding). A properly designed system can achieve 15-20 dB improvement over basic stud partition construction, making a very significant difference to perceived noise.
Can you skim over moisture-resistant or fire-rated plasterboard?
Yes, but with caveats. Fire-rated board skims exactly like standard board—no special preparation needed. Moisture-resistant board requires priming because the water-repellent additives reduce suction, potentially causing the skim coat to dry too quickly or not bond properly. Apply diluted PVA (3 parts water to 1 part PVA) or a proprietary bonding agent like Thistle Bond-It 24 hours before skimming. In direct splash zones (shower areas), don’t skim at all—use tile backer board and direct tile instead.
How long do different plasterboard types last before needing replacement?
Properly installed plasterboard should last the lifetime of the building—50+ years. Standard board in dry environments rarely degrades unless the building develops moisture problems. Moisture-resistant board in bathrooms typically outlasts the fixtures—you’ll refit the bathroom 2-3 times before the boarding fails. Fire-rated board maintains its rating indefinitely as long as it’s not damaged or wet. The limiting factor is usually cosmetic (outdated decor) or functional (remodelling layouts) rather than board failure.
What’s the difference between British Gypsum and Knauf plasterboard?
Both manufacture to the same British Standards, so performance is comparable. British Gypsum (Gyproc brand) has larger UK market share and more comprehensive technical support—their “White Book” technical manual is the industry bible. Knauf (German-owned but UK-manufactured) often has competitive pricing and some plasterers prefer their boards for ease of cutting and slightly lighter weight at equivalent thickness. For standard applications, choose based on price and availability. For complex fire-rated or acoustic specifications, use whichever manufacturer’s tested system the project specifies—you can’t mix-and-match components from different systems and maintain certification.
Understanding plasterboard types is fundamental to professional plastering work. Whether you’re a DIY enthusiast tackling a single room or a contractor managing complex builds, choosing the right board ensures regulatory compliance, long-term performance, and happy clients. For expert advice on your specific project, or for professional plastering services across Kent, contact Kent Plasterers for a no-obligation consultation and quote.