The Ultimate Guide to Hardie Backer Boards: A Must-Have for Tiling Projects

When it comes to tiling, the foundation is just as important as the tiles themselves. That’s where Hardie Backer Board comes in—a high-performance cement backer board that provides a strong, moisture-resistant surface for tile installations. Whether you're a professional tradesperson or a DIY enthusiast, using the right backer board ensures your tiled surfaces remain durable for years to come. 

At Tile Giant, we stock Hardie Backer Board in 6mm and 12mm thicknesses, ideal for use in wet areas such as bathrooms, kitchens, wet rooms, and showers. In this guide, we’ll explore why Hardie Backer Board is the best choice for your tiling projects, when to use it, and best installation practices. 

Hardie Backer Board is a cement-based tile backer board designed to create a solid and water-resistant foundation for tile installations. Unlike traditional plasterboard or plywood, it does not warp, rot, or weaken when exposed to moisture, making it ideal for high-humidity environments. 

1. Water and Mould Resistance 

Hardie Backer Board is engineered to repel moisture, significantly reducing the risk of mold and mildew growth behind tiles in wet environments. 

2. Unrivaled Strength and Durability 

Unlike plasterboard, Hardie Backer Boards won’t crumble or deteriorate over time. They provide a stable, long-lasting base, ensuring tiles stay firmly in place. 

3. Superior Tile Adhesion 

The specially formulated cement composition of Hardie Backer Boards allows for excellent tile bonding, preventing loose or cracked tiles over time. 

4. Fire Resistance 

Hardie Backer Board is non-combustible, making it a safer choice for homes and commercial spaces. 

5. Versatile Application 

Hardie Backer Board is suitable for walls and floors in various areas, including bathrooms, wet rooms, kitchens, and showers. 

Hardie Backer Board 6mm – Ideal for Floors 

• Perfect for bathroom and kitchen floors as an underlayment before tiling. 
• Adds extra durability to floor tiles, preventing cracks and movement. 
• Compatible with underfloor heating systems, allowing even heat distribution. 

Hardie Backer Board 12mm – Ideal for Walls 

• Recommended for wet rooms, showers, and bathroom walls. 
• Provides a sturdy, waterproof backing for tiles, preventing moisture penetration. 
• Stronger than plasterboard, ensuring long-term tile adhesion in high-moisture areas. 

Tools & Materials You’ll Need: 

• Hardie Backer Board (6mm or 12mm) 
• Tile adhesive or thin-set mortar 
• Notched trowel 
• Hardie Backer screws
• Fiberglass mesh tape 
• Utility knife or carbide-tipped scoring tool 
• Drill and screwdriver 
• Measuring tape 

Installation Steps for Walls and Floors 

For Floors (6mm Hardie Backer Board): 

1. Prepare the Subfloor – Ensure the floor is clean, dry, and level. 
2. Apply Thin-Set Mortar – Spread a layer of adhesive onto the floor using a notched trowel. 
3. Lay the Backer Board – Position the boards in a staggered pattern, leaving a small gap between sheets. 
4. Secure with Screws – Use Hardie Backer screws every 200mm (8 inches) to prevent movement. 
5. Tape and Seal Joints – Apply fiberglass mesh tape over the joints and cover with thin-set mortar. 
6. Let it Cure – Allow time for the mortar to set before tiling. 

For Walls (12mm Hardie Backer Board): 

1. Prepare the Surface – Remove any existing wall coverings and ensure the surface is dry and dust-free. 
2. Measure and Cut Boards – Score with a utility knife and snap to size. 
3. Fix to Studs or Solid Walls – Secure the board with Hardie Backer screws every 200mm (8 inches) into timber or metal studs. 
4. Tape and Seal Joints – Use fiberglass mesh tape over the seams and apply a thin layer of tile adhesive. 
5. Ready for Tiling – Once the adhesive sets, your wall is ready for tile installation. 

At Tile Giant, we supply premium Hardie Backer Board 6mm and 12mm, ensuring you get the best foundation for your tiling projects. Whether you're a professional tiler or a DIY enthusiast, investing in quality backer board is the key to long-lasting, moisture-resistant tiled surfaces. 

Browse our full range of tile accessories online or visit your nearest Tile Giant store to get expert advice and supplies for your next tiling project.