12.5mm Plasterboard
(27 Products)12.5mm plasterboard is the industry-standard thickness for drylining applications in both residential and commercial construction. This specific depth is the primary benchmark for internal partitions, providing the necessary structural rigidity and surface area for high-quality finishes while remaining light enough for efficient site handling.
Engineering & Specification Requirements
Specifying 12.5mm plasterboard is a technical requirement for most standard timber and metal stud partitions. This thickness provides the essential cross-sectional strength needed to span 600mm joist or stud centres without the risk of bowing or excessive deflection. Unlike thinner boards, the 12.5mm profile allows for deeper countersinking of drywall screws, ensuring a flush finish without compromising the integrity of the gypsum core.
The utility of 12.5mm boards extends into specific performance zones. It serves as the base thickness for technical boards - including moisture-resistant, sound-dampening, and fire-rated variants. By maintaining a consistent 12.5mm depth across different board types, contractors can transition from a standard bedroom wall to a moisture-prone ensuite or a fire-rated hallway without needing to adjust the framing or trim depths.
Application & Format Selection
- Standard Wall Linings: 12.5mm Wallboard for general-purpose partitions and ceilings in domestic environments.
- Kitchens & Bathrooms: 12.5mm Moisture Boards (Green) containing water-repellent additives to protect against humidity and damp.
- Fire-Rated Enclosures: 12.5mm Fire Boards (Pink) with glass fibre and additives to increase structural integrity under heat.
- Acoustic Partitions: 12.5mm Sound Boards (Blue) with a higher density core to reduce airborne noise transmission between rooms.
- Ceilings: 12.5mm Tapered Edge boards for a seamless, joint-filled finish that resists sagging over standard spans.
Frequently Asked 12.5mm Plasterboard Questions
Is 12.5mm plasterboard thick enough for 600mm joist centres?
Yes, 12.5mm is the industry-standard minimum thickness for 600mm joist or stud centres. Using a thinner 9.5mm board over this span can lead to visible sagging or "pillowing" between the supports once the weight of the plaster skim is applied.
What length of screw do I need for 12.5mm plasterboard?
You should use 38mm drywall screws for a single layer of 12.5mm board. This ensures the required 25mm penetration into the timber studs or joists, providing enough grip to support the weight of the board and any subsequent plaster finish.
How much height will I lose by overboarding with 12.5mm?
Including a standard 2mm-3mm plaster skim, you should account for a total depth reduction of roughly 15mm. If ceiling height is extremely limited, some contractors opt for 9.5mm, but 12.5mm is preferred for better flat-surface integrity and fire safety.
