Wallboard Standard Plasterboard

What is Wallboard? 

Wallboard is a flat panel made of a gypsum plaster core pressed between two thick sheets of paper. It's used to quickly create smooth interior walls and ceilings, ready for painting or wallpapering. 

Instead of applying wet plaster directly onto brick or block walls (which is a more traditional and time-consuming method), wallboard can quickly and easily be fixed to:

• Timber stud frames (the wooden skeleton of an internal wall)
• Metal stud frames
• Directly onto existing masonry walls (using an adhesive or a timber batten system - this method is often called "dot and dab" when using adhesive).

Once the plasterboard is up, the joints between the boards are taped and filled with a jointing compound (or the whole surface can be skimmed with a thin coat of plaster) to create a uniform surface, ready for decoration.

Composition

• The Core - Gypsum Plaster: Gypsum is a soft, naturally occurring sulphate mineral (calcium sulphate dihydrate). For plasterboard, gypsum is processed into a fine powder, mixed with water and other additives (like starch for bonding, foaming agents to reduce density, and sometimes fibres for strength) to form a slurry. This slurry is then fed between the paper liners.
• The Liners - Durable Paper: Two layers of heavy-duty paper encase the gypsum core. The face paper (typically ivory or white) is smooth and provides an ideal surface for direct decoration (painting or wallpapering) or for a thin skim coat of finish plaster. The backer paper (often grey) provides support and can have specific properties in specialised boards.
• Manufacturing: The gypsum slurry sets and hardens between the paper liners as it moves along a production line. The continuous board is then cut into standard sheet sizes and kiln-dried to remove excess moisture, resulting in a strong, rigid, yet relatively lightweight panel.

The key characteristics of standard plasterboard are its flat, smooth surface (on the face side), consistent thickness, and its readiness for finishing once installed.

Applications

• Internal Walls: Creating stud partitions using timber or metal framing, providing the wall surfaces on both sides.
• Ceilings: Fixed to ceiling joists or metal framing systems to create flat or sloped ceilings.
• Lining Existing Masonry Walls: Applied directly to solid brick or block walls using the "dot and dab" method (adhesive dabs) or fixed to timber battens (creating a service void) to provide a smooth, dry surface for decoration. This is known as dry lining.
• Shaft Walls & Encased Steelwork: Specialised plasterboard systems are used to create fire-rated enclosures around service shafts, lift shafts, and to protect structural steelwork.
• Part of Thermal or Acoustic Systems: Used in conjunction with insulation materials (e.g., mineral wool between studs, or as insulated plasterboard) to enhance thermal efficiency or sound insulation.

Benefits

• Speed of Installation: Significantly faster than traditional wet plastering methods (applying multiple coats of plaster to masonry or lath), reducing construction times.
• Smooth Finish for Decoration: Provides a consistently flat and smooth surface that is ideal for painting directly (after jointing) or for receiving a thin skim coat of finish plaster for a more traditional plastered look.
• Cost-Effectiveness: Relatively inexpensive material, both in terms of purchase price and the labour costs associated with its installation compared to traditional methods.
• Versatility: Can be used for walls, ceilings, partitions, and linings, and comes in various types tailored to specific performance requirements.
• Ease of Repair: Minor damage to plasterboard surfaces can often be easily repaired with filler and repainting.
• Dry Construction: Minimises the amount of water introduced into a building during construction (compared to wet plastering), leading to faster drying times for the overall project and less moisture for the building structure to absorb.

Common Sizes, Thicknesses, and Edge Types

Plasterboard is available in a range of standard sizes and thicknesses:

• Thicknesses:
  • 9.5mm: Sometimes used for ceilings or creating curved surfaces due to its greater flexibility, but less common for walls due to lower rigidity and impact resistance.
  • 12.5mm: The most common and versatile thickness for general wall and ceiling applications, offering a good balance of strength, manageability, and performance.
  • 15mm: Offers increased robustness, improved fire resistance, and better acoustic performance compared to 12.5mm. Often specified for party walls, ceilings requiring enhanced fire ratings, or where a more solid feel is desired.
• Sheet Sizes (Width x Length):
  • 1200mm x 2400mm (approx. 4' x 8'): This is the most standard sheet size. Some manufacturers use 1220mm x 2440mm which is the true imperial equivalent.
  • Other lengths are available, such as 1800mm, 2700mm, 3000mm.
  • Common widths are 1200mm or 900mm.
• Edge Types:
  • Tapered Edge (TE): The long edges of the board are slightly tapered. This allows for joint tape and jointing compound to be applied within the taper, creating a flush, seamless surface ready for direct decoration after sanding. This is the most common edge type for walls and ceilings where a flat, monolithic finish is desired.
  • Square Edge (SE): The edges are cut square. These boards are typically used when the entire surface is going to be skimmed with a thin coat of finish plaster, or for applications where visible joints are acceptable or will be covered by trim.

Finishing and Decorating

• Sealing/Priming: Newly jointed or skimmed plasterboard is porous and should be sealed or primed before painting or wallpapering. A "mist coat" (diluted matt emulsion) is often used on new plaster/joint compound, followed by standard primer or undercoat. 
• Painting: Accepts most types of interior paint (emulsion, acrylic, etc.) once properly primed.
• Wallpapering: A sealed/primed surface is essential for good adhesion and to allow for easier removal of wallpaper in the future.