Floating floors in buildings

A floating floor is a floor that is not fixed to the layer beneath it.

Floating floors may be constructed from materials such as timber planks or boards, engineered timber, laminate flooring and some types of tiles. These materials can be glued, snapped or otherwise fixed to one another, but are not fixed to the substrate layer beneath (which may be, for example, the structural floor, an underlay, an underfloor heating construction or acoustic or thermal insulation).

A floating floor is not the same as a raised floor (sometimes referred to as an access floor or raised access floor), which is a floor created above a solid floor slab, but with an open void between the two within which building services may be distributed.

Floating floors are particularly common in refurbishment works, and can be used to help improve the thermal or acoustic insulation of a floor construction.

Floating floors can be easier, faster and less expensive to install than fixed flooring, and may be easier to remove, for example, if access is needed to the floor structure itself or to a floor void or ceiling where services might be installed. They can be less deep than other types of flooring and cause less damage to the substrate below.

They can generally accommodate some movement between the flooring and the substrate, for example where the humidity of a room changes. This requires that a gap is left around the perimeter of the flooring, between it and the wall or skirting. These gaps may be filled with a flexible filler or concealed beneath an edge trim or skirting.

Floating floors are held in place as a result of their own weight, the boundaries of the room in which they are laid, the fixings between the elements of the floating floor, and friction between the floating floor and the substrate.

However, as they are not fixed down, they can move under loading, for example when walked on, in particular at the edges. This can lead to delamination, or cracking or separation of joints, as can differential movement between the flooring and the substrate. Where there is substantial movement, for example if the flooring becomes wet and expands, floating floors can be prone to buckling or bowing.

Floating floors can be noisy, sometimes creaking under loading, and they can give a hollow sound when walked on compared to the more solid sound experienced when walking on a fixed floor.

Many of these potential problems can be mitigated by the installation of a good quality underlay.

Approved document E: Resistance to the passage of sound, 2003 edition incorporating 2004, 2010, 2013 and 2015 amendments, states: ‘A floating floor consists of a floating layer and resilient layer.” Where a floating layer is: ‘A surface layer that rests on a resilient layer and is therefore isolated from the base floor and the surrounding walls.” And a resilient layer is: ‘A layer that isolates a floating layer from a base floor and surrounding walls.”

NB: Sprung floors, designed to give specific properties of shock absorption and energy return suitable for dance and sport, are generally floating floors.

[edit] Related articles on Designing Buildings

• Beam and block.
• Click and lock flooring.
• Concrete floor.
• Floor definition.
• Floor plenum airtightness.
• Flooring.
• Flooring defects.
• Floor slab.
• Laminate flooring.
• Plenum.
• Raised floor.
• Separating floor.
• Slab.
• Sprung floor.
• Suspended ceiling.
• Suspended timber floor.
• Types of floor.
• Types of skirting board.
• Underfloor air distribution.
• Underlay.
• Wall types.