Timber Flooring Installation Recommendations

Solid Timber Flooring Consideration

Installing hardwood timber flooring can transform the aesthetics and feel of your space, providing a durable and timeless flooring option. Whether you opt for solid timber or engineered boards, proper installation of timber flooring is important for the longevity and performance of your new floors. Here’s a detailed look at the installation process for solid timber flooring and the considerations in line with industry standards.

Installation Methods

Hardwood timber flooring can be installed using various methods, each suited to different substrates and preferences. Traditionally, Australian Standards mandate face-fixing for boards over 85mm wide. However, advancements in manufacturing have introduced wider boards that can be securely fixed without visible fasteners (secret fix). Additionally, instead of timber flooring (19mm +) installed with joists and battens, adhesives can offer direct-stick options with a substrate, reducing sound transmission to the home.

Installing Over Existing Timber & Plywood on Joists

What it involves

Solid overlay timber flooring can be installed over existing timber flooring or a plywood or particleboard substrate on joists.

Before proceeding with this installation, the following should be followed;

• Assess existing floor; replace defective boards or replace structural flooring if required
• Rough sand existing flooring
• Clean floors and check the moisture content of the existing floor prior to the installation of new boards
• Full trowel adhesive bed (the adhesive should be applied evenly using a 6mm V-notch trowel)
• Secret or top (face) nail fixing timber flooring to plywood or existing substrate, depending on the boards used
• Leave a recommended expansion gap of 10mm along all wall perimeters to accommodate natural timber expansion and contraction due to seasonal humidity changes
• Floor areas over 6m across the width require an additional 10mm expansion gap in the floor.

Note: Standard profile boards are manufactured for top/ face nail fixing. Secret nail profiles are designed to hide fixing; however, they can also be top/ face fixed if required. Solid 19mm thick flooring over 130mm width must be top nailed.

Direct Stick to Plywood on Concrete Slab

What it involves

Direct stick for hardwood timber overlay flooring over a concrete slab requires plywood sheeting and a polyethylene vapour barrier fixed through to the concrete slab. The polyethylene vapour barrier offers added protection against moisture from the slab.

Before proceeding with direct stick installation, the following should be followed;

• Slab flatness should not be more than 3 mm below a 3.0m straight edge. (achieving a level substrate ensures a stable and long-lasting timber floor. Self-levelling compounds can fill voids, while grinding high points ensures a smooth surface for adhesive application)
• Install 0.2 mm polyethylene vapour barrier
• Polyethylene should be lapped by 200 mm taped at the joints and brought up the wall to be covered by the skirting
• Fix plywood sheets through the membrane and into the slab, referred to as ‘spike’ fixed
• Full trowel adhesive bed (the adhesive should be applied evenly using a 6mm V-notch trowel)
• Secret or top (face) nail fixing timber flooring to plywood over slab
• Similar to timber substrate, leave a recommended expansion gap of 10mm along all wall perimeters to accommodate natural timber expansion and contraction due to seasonal humidity changes
• Floor areas over 6m across the width require an additional 10mm expansion gap in the floor.

Bowens Hardwood Timber Flooring Range

For a wide range of hardwood timber flooring species, including Blackbutt flooring, Tasmanian Oak, American Oak flooring and more, explore the Bowens website. Alternatively, visit our Circa Studio for flooring samples, advice and technical information.

Interested in installing engineered timber flooring? Check out our blog, “Engineered Timber Flooring Installation: Which Method Should You Use,” for advice.