Which type of plasterboard do I need?

Plasterboard variants are largely colour-coded and the choice usually follows from the room rather than from preference — but in some places, particularly garages and loft conversions, it is a Building Regulations requirement rather than a matter of taste.

Step by step

1. Use standard board for ordinary rooms.Grey or ivory faced, and the cheapest by a clear margin. Bedrooms, living rooms, hallways, and ceilings that are not part of a fire-resisting element.
2. Use moisture-resistant board in wet rooms.Usually green faced. Bathrooms, en suites, utility rooms and behind kitchen splashbacks. The core contains water-repellent additives, which slows damage but does not make it waterproof.
3. Do not confuse moisture-resistant with tile backer.Behind a shower or in a wet room, a cement-based or foam tile backer board is the correct substrate. Moisture-resistant plasterboard is for humid rooms, not for surfaces that get direct water.
4. Use fire-resistant board where required.Usually pink. A garage attached to a house, a ceiling under a loft conversion, a wall to an integral garage, and any element with a stated fire rating. This is a regulatory requirement, not an upgrade.
5. Check whether a loft conversion needs it.A loft conversion typically requires a fire-resisting ceiling to the floor below and protection to the escape route. The number of layers and the board type come from the approved design.
6. Use acoustic board where sound matters.Denser board with a higher mass, usually blue faced. It is heavier and more expensive, and it works best combined with insulation in the cavity and resilient bars.
7. Consider impact board for hard-wear areas.A tougher core and a stronger liner for hallways, playrooms and anywhere with heavy traffic. It also holds fixings better.
8. Consider foil-backed board for vapour control.A vapour control layer bonded to the back, used on the warm side of insulation. It is one way to build in a vapour barrier without a separate membrane.
9. Match the board type across the whole element.A fire-resisting ceiling with one standard board in it is not fire resisting. The performance is a property of the assembly, not the individual sheets.
10. Check the colours locally.The colour conventions are near-universal in the UK but not guaranteed. Read the board's edge printing, which states the type.

Tips

• Green board is not waterproof. Behind a shower, use a proper tile backer board.
• Fire-rated board in a garage or a loft conversion is a Building Regulations matter, so check the requirement before ordering.
• Acoustic board on its own does relatively little — mass, insulation and decoupling together are what reduce sound transmission.

Common mistakes

• Using moisture-resistant board as a shower substrate — It resists humidity, not water. Behind tiles in a shower it eventually softens and the tiles come away with it. A cement or foam backer board is the correct product.
• Substituting standard board in a fire-rated ceiling — The fire performance is tested for a specific board type and thickness. A standard board in that position reduces the rating of the whole element, and it will fail a building control inspection.

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