What Is Moisture-Resistant Plasterboard?
Moisture-resistant (MR) plasterboard is a gypsum board with a treated core and moisture-resistant paper facing that resists the absorption of water vapour and incidental splashing better than standard plasterboard. It is manufactured to AS/NZS 2588 and is the board type required by NCC 2022 for wet area wall linings in residential and commercial buildings.
MR plasterboard is not waterproof — it does not act as a waterproofing membrane. In wet areas such as shower recesses, AS 3740 (Waterproofing of Domestic Wet Areas) requires a separate waterproofing membrane to be applied over the board and into wall-floor junctions before tiling. MR board provides the correct substrate for the membrane and tile system and resists the ongoing humidity of the space once installed.
Using standard plasterboard in wet area applications is a compliance failure that can result in board deterioration, mould growth, tile failure, and costly remediation. MR board is the only plasterboard approved for wet area use in Australian residential construction.
Where MR Plasterboard Is Required
Bathroom Walls
All wall linings in bathrooms — including walls not directly adjacent to the shower — require MR plasterboard under NCC 2022. Both tiled and painted bathroom walls require MR board as the substrate.
Shower Recesses
Shower recess walls require MR plasterboard plus a waterproofing membrane applied to AS 3740 before tiling. The membrane must extend 1800mm above the floor on shower walls.
Laundry Walls
Laundry wall linings require MR plasterboard in areas subject to splash, steam, and ongoing humidity from washing machines and trough areas.
Kitchen Splashbacks
Kitchen splashback areas behind sinks and cooktops require MR plasterboard where the substrate is to receive tiles or other impervious finishes applied to the board surface.
Commercial Wet Areas
Commercial bathrooms, change rooms, commercial kitchens, and other high-humidity commercial spaces require MR plasterboard for all wall linings per NCC Volume 1.
Balcony and External Soffits
In some external and semi-exposed locations, MR board provides better durability than standard board where the surface will be painted and is exposed to condensation or indirect weather.
Products We Stock
CSR Gyprock Aquachek
CSR Gyprock Aquachek is Australia's most widely used moisture-resistant plasterboard. It features a treated green-tinted gypsum core and moisture-resistant paper facing, providing significantly better resistance to moisture absorption than standard board. Aquachek is CodeMark certified and is the standard MR board for NCC wet area compliance in Queensland residential and commercial projects. Available in 10mm and 13mm thicknesses in standard lengths.
Knauf Moistureshield
Knauf Moistureshield is a high-performance moisture-resistant plasterboard with a green-coloured moisture-resistant core. It meets the requirements of AS/NZS 2588 Class H (high moisture resistance) and is suitable for all NCC wet area applications. Knauf Moistureshield is compatible with all standard waterproofing membranes and tile adhesives and is available in 10mm and 13mm thicknesses.
James Hardie Villaboard
For high-performance wet area applications — shower recesses, around baths, floor-to-wall junctions in commercial bathrooms — James Hardie Villaboard fibre cement lining is an alternative to MR plasterboard. Villaboard is a fibre cement sheet that provides superior moisture resistance and dimensional stability compared to gypsum MR board and is the preferred substrate for shower areas in commercial and high-end residential construction. Ask our team about Villaboard availability and appropriate applications.
MR Plasterboard FAQs
No. MR plasterboard resists moisture absorption and is more durable in humid conditions than standard board, but it is not waterproof. In shower recesses and floor-to-wall junctions, AS 3740 requires a separate waterproofing membrane to be applied over the board before tiling. The membrane waterproofs the space; the MR board provides the correct substrate for the membrane system.
10mm MR board is suitable for bathroom walls on stud framing at 450mm centres. 13mm is recommended for studs at 600mm centres and provides better rigidity and impact resistance. For tiled shower walls, 10mm or 13mm MR board is standard, though James Hardie Villaboard fibre cement is preferred in commercial and high-specification residential shower applications for its superior dimensional stability.
In wet areas (shower recesses), you cannot tile directly over MR board — AS 3740 requires a waterproofing membrane to be applied first. In splash zones outside the shower recess (general bathroom walls, splashbacks), tiles can be applied directly to MR board using an appropriate flexible tile adhesive. Always consult the tile adhesive manufacturer's instructions for substrate preparation requirements.
Moisture-resistant plasterboard is typically green or blue in colour on the face paper, distinguishing it clearly from standard white plasterboard. CSR Gyprock Aquachek has a green face; Knauf Moistureshield has a green core visible on cut edges. Always check the product labelling when taking delivery to confirm the correct board type has been supplied.
NCC 2022 requires MR plasterboard for all wall linings in a wet area room — not just the shower recess. This includes non-tiled walls adjacent to the bath, vanity walls, and the back of bathroom doors where the lining faces into the bathroom. Standard plasterboard is not permitted as the wall lining substrate anywhere within a defined wet area room under the NCC.
MR Plasterboard in Stock Across Brisbane
CSR Gyprock Aquachek and Knauf Moistureshield available from all four Bayside Plasterboard branches.
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