Can I Install Underlayment Under Flooring with Pre-Attached Padding?

Dear Bob and Betsy,
When installing flooring, is it okay to use additional underlayment if the flooring already has attached padding?
-Craig S

Dear Craig,

Flooring with pre-attached padding (also known as underlayment) can be confusing to many DIY installers. You read articles touting the importance of using underlayment for moisture control, noise reduction, and overall support. It’s natural to wonder what you should do to maximize your floors longevity when the underlayment is already attached. When it comes to installing flooring, it is important to consider the type of flooring and the specific installation instructions provided by the manufacturer. In some cases, the flooring may come with attached padding or underlayment, which is designed to provide additional cushioning and insulation for the floor. We have compiled more information for you to help to decide what’s best for your project. Happy remodeling! Bob & Betsy

Avoid excessive padding to prevent potential problems

When installing a floor with pre-attached underlayment, we generally do not recommend adding extra padding.

Underlayment serves the purpose of providing cushioning for your flooring and allowing it to float. It is particularly important for floating floors, like laminate and vinyl, which expand and contract with temperature changes.

Some homeowners may be tempted to add even more underlayment or padding on top of the existing layer, either to further enhance the cushioning or to address issues with uneven subfloors. While adding extra underlayment may seem like a simple solution, it is not always the best idea. Adding too much underlayment can result in an unstable surface, similar to placing a thick sponge under your flooring. This instability can lead to issues such as buckling, separating planks, and permanent damage to the locking system.

Vapor Barrier

There is one exception to this rule – vapor barrier.

If you are installing your flooring with the pre-attached underlayment over a cement subfloor, you will want to use a vapor barrier. This type of underlayment is a moisture resistant film and does not have any additional padding, so it will not pose a risk to your flooring.

We recommend using our Visqueen Vapor Block PE Film. This plastic film will add moisture protection to your floor wherever there is a possibility of moisture coming up from the subfloor.

Installing new flooring involves numerous factors to consider, including the subfloor, underlayment, and type of flooring. Each element must be carefully evaluated to achieve best results. If you have any questions, our team of flooring experts is here to assist you in making your installation process hassle-free.

Learn More:

• Can You Put Down Two Layers of Laminate Flooring Underlayment to Reduce Noise Pollution?
• How to Install Visqueen Vapor Barrier PE Film – An Illustrated Step-by-Step Guide
• All You Need To Know About Laminate Flooring Underlayment