Wood Floor Underlays, Insulation & Sound Proofing

An important part of the wood floor fitting process is the installation of appropriate sound and damp insulation underneath. This is essential for both concrete and wooden subfloors to ensure that once installed the new wooden floors will be well protected from draft and moisture. Unless this is properly done at the beginning of the fitting process during the preparation of the subfloors, and unless it utilises the most appropriate insulation materials, it will be difficult to rectify at a later stage.

Proper floor insulation is essential to guarantee the quality of floorworks and the overall customer’s experience of their new floors. Various issues such as squeaking noise, wrapping or other deformation of the floors may appear if the floor insulation has not been done well. In addition, many properties with multiple occupants, such as blocks of flats have their specific requirements for the type of insulation that needs to be put in place before any floor works to ensure the comfort of surrounding residents.

Types of Wood Floor Underlays

The most appropriate type of insulation would normally depend on the type of the flooring to be installed and more importantly on the type of the subfloor.

One of the most common reasons for the need to install insulation is damp proofing. This can be done with the use of liquid damp proof membrane in case the subfloor is concrete. This is extremely important for hardwood floor fittingbecause when solid wood is laid over concrete subfloors it is in a direct contact with it and can be very vulnerable to any changes in humidity levels. As a natural product, hardwood flooring tends to contract and expand in a response to humidity and temperature variation. However, if the subfloor is wooden floorboards, then plastic film or an underlay would be the applicable solution. Most of the wood floor underlays on the market today come with incorporated damp proof membrane, which increase their efficiency.

Insulation is also important to ensure draft prevention, which can significantly improve the energy efficiency of any home or office. This is particularly the case where the subfloor consists of the original pine floorboards, which may have experienced a great deal of deformation over the years, causing the appearance of gaps and hence allowing significant draft into the property. In addition, this is often accompanied by a poor noise insulation making it uncomfortable for the occupants. Therefore, insulation with the use of Rockwool is often required to help resolve these issues. Rockwoll is placed between the joists to fill in the space, which will significantly reduce the transmission of noise and draft. Where the installation of Rockwool is the preferred method of insulation, this often required the supply and replacement of some of the floorboards as it is inevitable that some of them will be damaged in the process. FloorWorks and supply and fit reclaimed pine floor boards matching the size and the age of your pine floorboards to ensure a match as close as possible.

It is sometimes also recommended that fibreboard or plywood is installed on top of the floorboards, particularly for laminate floor installation and engineered wood fitting to ensure that the subfloor is flat and even. This will further increase the sound and thermal insulation. Plywood and chipboard are also often used to completely replace old subfloors. They are very effective as they provide good level of insulation as well as perfectly smooth and even level, which makes the floor installation process much easier and more efficient. For these reasons, installation of playwood or chipboards often goes with the subfloor preparation for parquet flooring fitting.

In case engineered wood flooring or laminate floor installation over concrete subfloors, the most common solution for sound and moisture insulation is the laying of underlay. Most underlays provide sound-proofing of air-borne sound of up to 18-24 dB. However, there are products on the market today, such as “Timbertech2 Contract HD 5” offering a sound-proofing rate of 28 dB.

In any case, insulation is a very important thing to do while having new floors installed. Once you miss the opportunity to do this before the installation of new floors, it will be years until you have the chance to do it again.

The table below provides a comparison of some of the most common types of insulation products available on the market today.