Flooring Underlay & Insulation



With a wood floor installation project awaiting you, you may find out that you actually need a flooring underlay. A flooring underlay will not be a part of every wood floor installation service. However, in some cases and situations, a flooring underlay is necessary for the project. In other situations, homeowners just opt for a flooring underlay because of the advantages it offers and the benefits it can ensure. There are a few types of flooring underlay available on the market, each of them having its specific function and offering its specific advantages. So if you need to have a flooring underlay installed before the floorboards, or you simply are interested in what a flooring underlay is and what it will add to the wood floor installation project, here is the information you need.

What Is Flooring Underlay And Why It Is Needed?

What is flooring underlay and why it is needed
What is flooring underlay and why it is needed

A flooring underlay is an additional layer of material that is installed before the wooden or laminate floorboards and remains between the subfloor and the fitted floor. A flooring underlay can be manufactured from different materials to serve a different function and purpose, also comes in varying thicknesses, depending on the material it is made out of. Below we will discuss the different types of flooring underlay. 

Depending on the type of flooring underlay chosen, the flooring underlay will work as a moisture barrier between the subfloor and the floor, protecting the floorboards from water damage, increase the insulation of the floor, add more durability and stability, create a cushioning effect for extra comfort of use, make the floor more solid and hard-wearing, have a sound-proofing effect and reduce the transfer of noise.

Having a flooring underlay installed is not always necessary and it is a matter of choice. However, in certain situations, you are highly recommended to have a flooring underlay installed in order to ensure your floor will last for a long time and ensure its stability, solidness, strength, durability. For example, when it comes to a floating installation that is often used for engineered wood and laminate floors and does not involve the use of adhesive or nails, having a flooring underlayment installed is important.

Installing a flooring underlayment is also highly recommended for cases when the subfloor cannot be levelled or completely dry for some reason - it will block the moisture from affecting the condition of the floorboards. Finally, if you want to have an underfloor heating system installed, you are recommended to also opt for a flooring underlay. 

Roll Flooring Underlay

Roll flooring underlay
Roll flooring underlay

This type of flooring underlay is usually offered on the market with a thickness of 3 mm. This type of flooring underlay tends to compress and has slight absorbent properties. This type of flooring underlay has great acoustic properties and is often chosen for its sound-proofing power. It reduces noise pollution significantly. 

Silver Flooring Underlay

Silver flooring underlay
Silver flooring underlay

Every silver flooring underlay has a built-in vapour barrier. The vapour barrier is also known as a damp-proof membrane and works exactly how you would imagine in it - the flooring underlayment creates a damp-proof membrane that blocks moisture from transferring from the subfloor to the floorboards and damaging them. However, keep in mind that this type of flooring underlayment will be efficient at protecting the floorboards from moisture as long as the relative moisture content of the subfloor does not exceed 75%.

This type of flooring underlay is designed to be used on all ground floors More and more wood flooring professionals are nowadays requiring the installation of a silver flooring underlay with vapour whenever it comes to a wooden floor being installed on the ground floor in order to protect the floorboards from potential moisture damage, in the long run, thanks to the protective power of the flooring underlay. 

No-Vapour Flooring Underlay

No vapour flooring underlay
No vapour flooring underlay

Another popular type of flooring underlay is the no-vapour one. It looks very much like the silver flooring underlay but without the layer in silver or gold, which means it has no vapour. This type of flooring underlay cannot protect the floor from moisture, therefore it is often chosen for floors that are installed above ground level. It is very thin, therefore it also does not have very significant sound-proofing properties, despite the fact it can absorb a bit of noise pollution. This type of flooring underlay is often used for levelling the subfloor, which is a great option whenever the subfloor cannot be uniform or even for some reason, or levelling costs too much. 

White Flooring Underlay

White flooring underlay
White flooring underlay

This type of flooring underlayment is also commonly referred to as white foam underlay. It is a very thin and lightweight type of flooring underlay. It is also the cheapest option for all types of underlayment. It is a budget-friendly option whenever you need to have a flooring underlay installed before the floating installation of an engineered wood or laminate floor. However, this type of underlayment does not have very strong sound-proofing or insulating properties. 

Combi Flooring Underlay

Combi flooring underlay
Combi flooring underlay

This type of underlayment is usually not sold in rolls but in pieces that are folded. Also known as a foam cantilever, it is also around 3 mm thick and comes with a built-in vapour barrier. Therefore, this type of underlayment is often used for ground floors to prevent the floorboards from getting damaged by moisture and has good insulating properties. It is similar to the silver underlayment described above. 

Block Board Flooring Underlay

Block board flooring underlay
Block board flooring underlay

This type of underlayment can be made out of different materials, including fibres, mixed wood composite, plywood, cork or chipboard particles, lightweight polystyrene material, etc. This is a thicker underlayment option with a thickness usually ranging from 5 to 7 mm. This type of underlayment offers excellent levelling properties, which means that if the subfloor has just slight imperfections, this type of underlayment is enough to ensure the floor installed on top of it will be even, sturdy, and durable.

This type of underlayment does not come with a vapour barrier built-in, which means it does not have insulation properties and does not block moisture from affecting the floorboards. When it comes to ground floor installation, you can plan on using this type of underlayment together with a damp-proof membrane. 

What is flooring underlay and why it is needed?
Roll flooring underlay
Silver flooring underlay
No-vapour flooring underlay
White flooring underlay
Combi flooring underlay
Block board flooring underlay