New Zealanders often use GIB® as a generic term for plasterboard, but it is in fact a registered brand manufactured by Winstone Wallboards (a Fletcher Building subsidiary). The product is a sandwich panel: a dense gypsum core encased by heavyweight recycled liner paper. Introduced locally in the late 1920s and re-branded GIB® in the 1940s, it has become the default wall and ceiling lining for residential, commercial and light-industrial buildings nationwide.
GIB® is Winstone Wallboards’ gypsum-core plasterboard lined with 100 % recycled paper. The board’s in-built fire, acoustic and bracing performance – plus nationwide distribution – have given it a 94-95 % share of New Zealand’s wall-lining market. Its specialty variants (Aqualine, Fyreline, Barrierline, X-Block, etc.) meet virtually every New Zealand Building Code lining requirement. Understanding the composition, benefits, fixing and stopping processes and its monopoly context is important for DIYers, arhitects and tradies alike.
Composition & Manufacturing
Gypsum rock is quarried, crushed and calcined to remove part of its chemically bound water. The resulting plaster is blended with starches, foaming agents and, in some boards, glass fibres before being laid as a continuous slurry between two sheets of liner paper.
Both face and back liners are produced from recycled newspapers and card. This paper gives the board tensile strength, impact resistance and an ideal surface for stopping compounds and paint.
For special purpose boards there are additives. For Gib Fyreline® plasterboards glass micro-fibres are added to boost core cohesion and fire endurance. For Gib Aqualine® are added waxes and surfactants to limit water uptake while GIB X-Block® designed for hospitals X-ray suites has added barium sulphate which shields against X-ray or gamma radiation.
Gib® Product Range (and When to Specify Each)
| Variant | Nominal Thickness | Typical Use | Key Extra Ingredients |
|---|---|---|---|
| GIB Standard | 10 & 13 mm | General walls & ceilings | None |
| GIB Aqualine® | 10 mm | Bathrooms, laundries | Silicone & wax |
| GIB Fyreline® | 13 mm | Inter-tenancy & egress | Glass fibres, extra gypsum |
| GIB Barrierline® | 25 mm twin-layer | Terrace/duplex boundary | Staggered joints, higher density |
| GIB Noiseline® | 13 mm | Media rooms | High-mass core |
| GIB X-Block® | 15 mm | Hospital X-ray suites | Barium sulphate |
Each board meets a specific NZ Building Code clause – e.g., Clause C3 Fire, Clause G6 Airborne & Impact Sound, Clause B2 Durability.
GIB® Special Performance Boards
Fire Resistance – GIB Fyreline®
Gypsum contains ~21 % chemically bound water that vaporises at 100 °C, delaying heat transfer until fully calcined. Fyreline boards integrate glass fibres to hold the core intact for 30–120 minutes in furnace tests (AS 1530, ISO 834 curves).
Acoustic Control – Noiseline®
Mass, cavity depth and decoupling determine wall STC ratings. A single 13-mm Noiseline sheet each side of 92-mm studs with 75-mm glasswool and resilient rail hits STC 56 – adequate for home theatres.
Structural Bracing – EzyBrace®
Under NZS 3604:2011, lined timber walls can be treated as bracing elements. GIB® EzyBrace tables assign up to 120 BUs/m for double-sided Fyreline with HandiBrac hold-downs.
Typical Uses in NZ Construction
Residential interiors – standard walls, ceilings, bulkheads.
Wet areas – bathrooms, laundries, SPAs (Aqualine).
Inter-tenancy fire & acoustic walls – apartment and terrace boundaries (Barrierline, Fyreline).
Commercial fit-outs – office partitions, healthcare shielding (X-Block)
Plasterboard can be direct-bonded to masonry, screwed to steel studs or glued & screwed to timber. Proper GIB fixing ensures fastener spacing and adhesive beads meet manufacturer bracing tables.
Frequently Asked Questions
What is GIB board made of?
Calcined gypsum, recycled paper liners and trace starches/binders.
Difference between plasterboard and GIB board?
GIB is a leading NZ-specific brand; composition is similar but GIB carries proprietary fire, acoustic & bracing tests.
Is GIB fire-rated?
Fyreline and Barrierline achieve 30-120 min FRR when installed per system manual.
Can I recycle GIB off-cuts?
Yes, Winstone offers collection points, also gypsum is compostable.
Who invented plasterboard?
Augustine Sackett patented the first gypsum board in 1894.
