Why do I need to use an underlay for laminate flooring?


Prior to laminate flooring installation, it is essential that a good quality underlay is laid over the sub-floor. For those who have little or no knowledge at all, the underlay is this soft layer of cushioning, which is placed between the sub-floor and the laminate flooring and it is usually made of foam, sponge rubber or felt.

Apart from the fact that an underlay for laminate flooring will improve its final look and quality, there are many other reasons why you can't avoid having one. As every sub-floor has some minor imperfections, an underlay will help your laminate floor to float and expand without abrasion on uneven surfaces, by creating a perfect level surface. In addition to that, it will:

  • protect your laminate flooring from moisture when fitting over a cement sub-floor
  • provide your floor with extra thermal insulation and improve warmth
  • absorb noises when walking on the floor

Add to these benefits, the feeling of softness you will get when you walk on the flooring and you really start to realize how important it is to use an underlay with laminate flooring. But since there are many different types and thicknesses of underlays in the market, how will you know which one is the most appropriate for you?

Factors to be considered when choosing an underlay for laminate flooring:


Generally, most types of underlay are suitable with laminate flooring, due to the fact that laminate flooring is fitted as a floating floor, with no need to be fixed with nails, glues or staples. Two major factors though, will help you to decide which one is ideal for you.

The two most important factors you need to consider when choosing an underlay for laminate flooring, is the type of sub-floor you have in the room, on which the floor will be fitted and the kind of insulation you want to provide to it. Usually the sub-floor consists of either concrete or a wooden floor base. Depending on these two factors, there are different available options to suit your needs.

Underlayment over concrete sub-floor:

If your sub-floor is made of concrete, then it is necessary that you use a moisture resistant underlay (Vapour barrier). A “Damp proof underlay” will be the best option on this occasion, as it will provide a supreme protection against moisture coming up from your concrete sub-floor on to your laminate flooring. This type of underlay will ensure your planks will not swell and get damaged from moulds, once the moisture evaporates and you can even use it in basement projects.

Alternatively, you could use a Polyfoam underlay, but then a Damp proof membrane will need to be added. This can either be in the form of sheets, or a 2 part damp proof membrane, which is a liquid resin that sets to seal the concrete sub-floor.

Image courtesy by: safeguardeurope.com Image courtesy by: safeguardeurope.com

Note: These options are suitable for areas with high moisture levels such as bathrooms or basements.

Underlayment over plywood/wooden sub-floors:

If your sub-floor is made of wood, then there is a big range of underlays to choose from and your final selection should be based on a few factors that are described below.

If you want to create a quite environment in to the room you are fitting your laminate flooring (an office for example), or you live in a flat or apartment, the best option would be to invest in a sound resistant underlay. A rubber underlay will not only provide you with an outstanding impact sound and in-room noise insulation, but will also protect your laminate flooring against moisture migration from the sub-floor. In addition to that, it provides thermal and shock insulation.


In case you hate cold and want to protect from it as much as possible, while keeping your gas/electricity bills low, the best option would be to invest in a thermal insulation underlay. Such underlay will not only provide the room with thermal insulation, but will also reduce the noise and make walking on the laminate floor a pleasant experience.

Finally, for those having an underfloor heating, there is a suitable flooring underlay to choose. As you understand, it is really important that you don't choose the wrong flooring underlay on this instance, as it can reduce its performance and cause the system to overheat. There are flooring underlays specifically designed to be used with underfloor heating.

If you have further questions or concerns regarding how to choose underlay for your laminate flooring, leave me a message and I will reply to you as soon as possible.