Drywall, commonly known as plasterboard in Australia, is a building panel made of a gypsum core sandwiched between thick sheets of paper. It is the standard material used for constructing interior walls and ceilings in both residential and commercial buildings. Plasterboard is lightweight, affordable, quick to install, and available in specialised types including moisture-resistant, fire-rated, and soundproof varieties. In Australia, professional installation typically costs between $30 and $60 per square metre.
Plasterboard has been the dominant wall and ceiling material in Australian construction for decades. It replaced the older and more labour-intensive wet plaster method, offering builders and homeowners a faster, more cost-effective way to finish interior spaces. Whether you are building a new home, renovating, or simply trying to understand what is behind your walls, knowing how plasterboard works helps you make better decisions about construction quality and maintenance.
What Is Drywall?
Drywall, also called plasterboard, gypsum board, or by the brand name Gyprock in Australia, is a panel made of a gypsum plaster core pressed between two thick sheets of paper. It is used to create smooth, flat surfaces for interior walls and ceilings. The material is lightweight but strong enough to handle normal household wear.
Brief History
Drywall was invented in 1916 as a faster and more affordable alternative to traditional wet plaster walls. It gained wide adoption during the housing booms of the mid-20th century, particularly after World War II, when the demand for rapid construction methods was at its peak. Today, plasterboard is a standard part of building practices across Australia and the world.
Drywall vs Plaster
| Drywall (Plasterboard) | Traditional Plaster | |
|---|---|---|
| Material Composition | Gypsum core with paper facing | Lime, cement, or gypsum mixed with water, applied over lath |
| Installation Process | Installed in large sheets, then taped and finished | Applied in multiple layers over wooden lath or metal mesh |
| Drying Time | Quick installation, minimal drying time | Requires multiple coats and extended drying between each |
| Cost | More affordable, lower labour costs | Higher labour and material costs |
| Durability | Good durability, but can be damaged by impact | Extremely durable but prone to cracking over time |
Types of Drywall Panels
Different types of plasterboard are available to suit various construction needs:
- Standard plasterboard: The most common type, used for general wall and ceiling applications in dry areas.
- Moisture-resistant (green board): Designed for bathrooms, kitchens, and laundry rooms where humidity is a concern. Uses a water-resistant core and facing.
- Fire-rated plasterboard: Manufactured with fibreglass and other additives to slow the spread of flames. Commonly used in garages, stairwells, and commercial buildings.
- Soundproof plasterboard: Designed with extra layers or denser cores to reduce noise transmission. Suitable for home theatres, bedrooms, and office spaces.
- Impact-resistant plasterboard: Reinforced for high-traffic areas like hallways, schools, and commercial spaces where walls are more likely to be bumped or hit.
Common Thicknesses and Sizes
In Australia, plasterboard comes in standard thicknesses and sheet sizes:
| Common Use | Notes | |
|---|---|---|
| 10mm | Walls in residential properties | Adequate strength, lightweight |
| 13mm | Ceilings to prevent sagging, particularly in larger spans | Most common ceiling thickness in residential builds |
| 16mm | Commercial applications and areas needing extra fire resistance | Used where higher performance is required |
Standard sheet sizes are 1200mm x 2400mm and 1200mm x 3000mm, though custom sizes can be ordered for specific projects.
The Installation Process
Framing
Secure wooden or metal studs to create the wall or ceiling framework, making sure alignment and support are correct. Stud spacing is typically 450mm or 600mm on centre.
Measuring and cutting
Cut plasterboard panels to fit the required dimensions using a utility knife or saw. Measure twice and cut once to minimise waste.
Securing panels
Attach the panels to the framework using screws or nails, making sure they sit flush and are properly fastened at regular intervals.
Taping and mudding
Apply joint tape and plaster compound (mud) to all seams and screw holes for a smooth, continuous surface.
Sanding and finishing
Sand the dried compound to achieve a smooth surface ready for painting or wallpapering. Multiple coats may be needed for higher finish levels.
Priming and painting
Apply a primer coat before the final paint for a professional, durable finish that adheres properly to the plasterboard surface.
Finishing Levels Explained
Plasterboard finishes are graded by level, with Level 5 being the highest quality:
- Level 1: Basic joint taping for concealed areas like attics and storage spaces.
- Level 2: A thin coat of compound for semi-finished areas like garages, where appearance is secondary.
- Level 3: Additional layers of compound for light texture, suitable for walls that will receive heavy wallpaper.
- Level 4: A smooth finish ready for standard paint or wallpaper, suitable for most residential and commercial applications.
- Level 5: The highest quality finish, ideal for glossy paints and spaces with bright lighting where any imperfection would be visible.
During a pre-purchase or defect inspection, inspectors assess plasterboard finishes for quality issues including visible nail pops, cracking along joints, uneven surfaces, and signs of moisture damage. These are among the most common cosmetic defects found in new builds.
Benefits of Drywall in Construction
- Fire resistance: Fire-rated plasterboard slows the spread of flames, providing additional safety time during a fire event.
- Sound insulation: Soundproof plasterboard reduces noise transmission between rooms, improving comfort in multi-room dwellings.
- Energy efficiency: Plasterboard contributes to thermal insulation, helping maintain indoor temperatures and reduce energy costs.
- Quick installation: Significantly faster than traditional plaster, reducing labour costs and project timelines.
- Cost-effectiveness: Affordable material with lower installation costs compared to alternatives, making it budget-friendly for most projects.
Maintenance and Repair
Proper maintenance extends the life of plasterboard and prevents costly repairs:
- Use moisture-resistant plasterboard in wet areas and address any leaks immediately
- Fill small holes with spackle or filler compound, sand smooth, and repaint
- For larger holes, cut out the damaged section and patch with a new piece of plasterboard
- Repair cracks along joints with joint compound and reinforcing tape
- Watch for signs of mould on plasterboard surfaces, particularly in bathrooms and kitchens, as this may indicate a moisture problem behind the wall
For more on identifying moisture-related issues, see our guide to mould inspection techniques.
Cost Considerations
| Material Cost (per sheet) | Installation Cost (per sqm) | |
|---|---|---|
| Standard Plasterboard | $10 to $20 | $30 to $60 |
| Moisture-Resistant | $15 to $30 | $35 to $65 |
| Fire-Rated | $20 to $40 | $40 to $70 |
| Soundproof | $25 to $50 | $45 to $80 |
Costs vary based on project size, location, finish level, and whether the installation includes removal of existing wall or ceiling materials.
Key Takeaways
- Drywall (plasterboard) is a gypsum-based panel used for interior walls and ceilings in Australian residential and commercial construction.
- Specialised types include moisture-resistant, fire-rated, soundproof, and impact-resistant plasterboard for different applications.
- Standard thicknesses in Australia are 10mm for walls, 13mm for ceilings, and 16mm for commercial or high-performance applications.
- Installation involves framing, cutting, securing panels, taping joints, sanding, and painting, with five finish levels from basic to premium.
- Professional installation in Australia typically costs between $30 and $60 per square metre for standard plasterboard.
- Common plasterboard defects include nail pops, joint cracking, uneven surfaces, and moisture damage, all of which are checked during building inspections.
- Proper maintenance including prompt leak repair and using moisture-resistant board in wet areas extends plasterboard lifespan significantly.
Frequently Asked Questions
QWhat is the difference between drywall and plasterboard?
Drywall and plasterboard are the same product. "Drywall" is the term commonly used in North America, while "plasterboard" is the standard term in Australia and the UK. Both refer to a building panel made of a gypsum core between paper facings, used for interior walls and ceilings.
QWhat types of plasterboard are available in Australia?
The main types available in Australia are standard plasterboard for general use, moisture-resistant (green board) for wet areas, fire-rated plasterboard with enhanced fire resistance, soundproof plasterboard for noise reduction, and impact-resistant plasterboard for high-traffic areas. Each type is designed for specific applications and conditions.
QHow much does plasterboard installation cost in Australia?
Professional plasterboard installation in Australia typically costs between $30 and $60 per square metre for standard board. Specialised types like fire-rated or soundproof plasterboard cost more, ranging from $40 to $80 per square metre installed. The total cost depends on the project size, complexity, finish level, and location.
QWhich plasterboard thickness should I use for walls and ceilings?
In Australia, 10mm plasterboard is the standard choice for residential walls. For ceilings, 13mm is recommended to prevent sagging, especially across larger spans. For commercial applications or areas requiring additional fire resistance or soundproofing, 16mm plasterboard is commonly used.
QCan I install plasterboard myself or do I need a professional?
Basic plasterboard installation can be done as a DIY project for straightforward wall or ceiling applications. However, achieving a high-quality finish, particularly at Level 4 or Level 5, requires skill and experience with taping, mudding, and sanding. For the best results, especially in new builds or major renovations, professional installation is recommended.
QIs plasterboard fire-resistant?
Standard plasterboard offers some fire resistance due to the gypsum core, which contains water that is released as steam when exposed to heat, slowing the spread of fire. Fire-rated plasterboard is specifically manufactured with fibreglass and other additives to provide significantly enhanced fire resistance. It is required by the NCC in certain locations such as garages, stairwells, and shared walls.
QHow do I repair a hole in plasterboard?
For small holes, apply filler compound, let it dry, sand smooth, and repaint. For larger holes, cut out the damaged area in a square or rectangular shape, fit a new piece of plasterboard, secure it with backing support, apply joint tape and compound over the seams, sand smooth, and repaint. Patch kits are available at most hardware stores for simple repairs.
QWhat causes cracks in plasterboard walls and ceilings?
Common causes of plasterboard cracking include normal building settlement, movement in the timber frame due to moisture changes, poor joint taping during installation, impact damage, and structural movement. Cracks along joints are usually cosmetic and can be repaired with compound and tape. Cracks that are wide, recurring, or appear in unusual patterns may indicate a structural issue that should be assessed by a building inspector.
QShould I use moisture-resistant plasterboard in my bathroom?
Yes. Australian building standards require moisture-resistant plasterboard in wet areas including bathrooms, laundries, and kitchens. Standard plasterboard absorbs moisture, which can lead to swelling, mould growth, and structural deterioration over time. Moisture-resistant board has a treated core and water-resistant facing that performs significantly better in humid conditions.
QWhat plasterboard defects do building inspectors look for?
Building inspectors check for nail pops (fasteners pushing through the surface), joint cracking or bubbling tape, uneven surfaces, poor finish quality, signs of moisture damage or mould, and incorrect use of plasterboard types (for example, standard board used in a wet area instead of moisture-resistant board). These are common findings during pre-purchase and defect inspections.
References and Resources
- Australian Building Codes Board (ABCB) - National Construction Code requirements for wall and ceiling construction
- Standards Australia - AS/NZS 2588 Gypsum Plasterboard - Australian standard for gypsum plasterboard products
- CSIRO - Building Materials - Research on building materials and performance in Australian conditions
- Victorian Building Authority (VBA) - Building standards and compliance information
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Building or renovating and want to make sure your plasterboard work meets Australian standards? Owner Inspections provides independent construction stage inspections and defect investigations across NSW, Victoria, and Queensland. Book your inspection today or call us on 1300 471 805.