What is Laminate Underlayment?

Jim Williams
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When installing a laminate floor, you may have encountered the term “underlayment”. Laminate underlayment is a material placed between the subfloor, or foundation for a floor, and the laminate floating floor. It serves to cancel out the nuisances, such as noise, stability, or moisture after the floating laminate floor is installed. While the subfloor provides the foundational support for the room, the underlayment is intended to enhance and protect the flooring itself, while offering that extra foundation.

When Should You Use Laminate Underlayment?

Using a laminate underlayment is actually a common practice, and in some situations, is required for floating laminate floors. (Floating floors are not directly glued to the subfloor but glued or locked into each other.)

What Type of Laminate Floors Should You Look For?

Proper selection and installation of underlayment is important because it can affect how your laminate flooring feels and wears over time. The type of underlayment that is chosen for a laminate flooring project should be based on the environment that it is being installed in, the type of floor that has been purchased, and the overall structure of the space. 

There are several types of laminate underlayments that serve a number of purposes, which should be used in the proper situation. If you are planning to install a laminate floating floor and you have no idea what laminate underlayment to use, read on.

Standard Foam Underlayment

The most common type of underlayment is standard foam. There are many brands, thicknesses, and roll sizes, but they all serve the same function - which is to reduce sound, provide for slight cushioning, and provide minor added stability. Also, standard foam does not have any protection against moisture, so it should not be used with a concrete floor that is not on the ground level. Foam can be used on cement slabs as long as there is no chance for moisture, such as on the second floor.

Simple Moisture-Proof Underlayment

A simple moisture-proof underlayment may be used to prevent moisture from getting into and damaging the laminate floating floor. However, simple moisture-proof underlayments do not provide any solution for hollow or loud-sounding floors. For a better result, you can place this below standard foam to get a dual protective effect (both moisture and sound).

Combo Underlayment

Combo underlayment is a standard foam underlayment that has a built-in moisture barrier on one side. This moisture-proof barrier prevents moisture from seeping into the underlayment and the laminate floating floor, thus preventing any serious water damage. The combo underlayments can be used on or below ground levels as well, especially on laminate floating floors above concrete slabs. However, combo underlayments provide little sound reduction, comfort and stability.

Cork Underlayment

Cork underlayment is the most desirable laminate underlayment type. As the name implies, it is made of cork. Cork underlayments will give laminate floating floors almost the same sound and feel as a real hardwood floor. With cork underlayments, not only do you get optimum sound reduction, you will also create the illusion of a real hardwood floor. However, cork underlayments do not usually come with moisture-protective barriers, so you would want to use simple moisture-proof underlayments beneath cork underlayments for protection as well as comfort. Keep in mind that cork underlayments will raise the height of the floor.

Cement Board

Where cork and foam are lighter in weight, a cement board underlayment is a study option for your underlayment. Wonderboard, DuRock, or Hardie Boards are popular brands of cement board. Downfalls is that the board is that is heavy to transport. Proponenets enjoy the durability and strength that the cement board provides.

What Happens When You Don’t Use Underlayment?

Without underlayment, a laminate floating floor may have severe problems, either short- or long-term. There are two major problems that can occur, the first being a problem with loud, hollow sounds that could occur while the second is possible destruction of the laminate floating floor due to moisture from below, especially if installed on concrete. Now that you know what will happen without it, let us browse the four types of underlayment to figure out what will work for you:

Installing Underlayment

  • Time: Weekend (15-20 hours)
  • Price Range: $250 - $500, depending on materials used
  • Difficulty: Moderate

Follow these video tutorials to learn how to install underlayment:

DIY Network: “How to Install Underlayment and Laminate Flooring”

RONAinc: “Laminate Flooring: Installing the Underlayment”