Wooden Flooring Installation Methods
There are 3 main methods of fixing down wooden flooring; glue-down, secret nailing or floating. Which is the best?
Floating wooden floors
A floating floor is where the boards are lightly glued together with PVA wood glue along the tongue joint and laid onto a foam matting or underlay over the existing floor. They are called ‘floating’ floors because of their tendency to move if there are any peaks or hollows in the floor underneath, the sub-floor. There is no physical adhesion between the new wood floor and the old floor and, as a result, some floating floors may flex, squeak or sound ‘hollow’ when walked on, especially if the sub-floor has not been prepared correctly. This is a cost effective way of laying wooden flooring but the end result is often disappointing due to the movement. You can only float engineered wood flooring as solid boards have a tendency to twist if laid in this way.
Nailed wooden floors
Traditionally, secret nailing through the tongue of the board was the preferred fixing method when laying wooden flooring. The installer uses either a manual or a pneumatic nail gun and fires special wood fixing nails or cleats through the tongue, which is then hidden when the corresponding groove abuts the board. Solid or engineered wood flooring can be laid to timber battens laid on the floor or direct to timber floor joists. In some cases the timber joists can be stuffed with insulation and overlaid with membrane to reduce cold spots in older houses. Alternatively, nailed floors can be used on concrete sub-floors by fitting a 16-18mm layer of plywood or OSB to the concrete first. The resulting nailed floor will feel solid and substantial during use. That said, nailed installation is a specialist skill and should is not recommended for the amateur DIY’er!
Glued down wooden floors
Glued down installation is probably the most common wood floor fixing method used these days. Here the new floor is laid using a full coverage flexible wood adhesive to the sub-floor; which could either be a concrete screed, existing floor boards or a plywood/OSB board. Modern silane adhesives are applied to the sub-floor using a trowel, a little like tile cement, and the boards are placed directly on top. These new wood adhesives are very strong, odour free, water based and have a good ‘open’ time allowing ample time to complete large areas of flooring using an open tub. A glued down wood floor will feel as solid underfoot as a nailed floor and, because the glue is flexible, natural seasonal expansion and contraction can occur without stressing the floor.