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
69 comments
The laminate flooring I purchased as the attached underlayment but on some boards, it’s ripped or falling off. I have cork underlayment that I purchased separately. Rather than installing the laminate with the attached underlayment on top of the cork, could I just remove the attached underlayment and put the bare board on top of the cork? I’m thinking the cork would provide more moisture protection and sound reduction than just the attached underlayment.
Thanks for your question, Dave! That may not be enough cushion for a laminate floor. We would suggest verifying with the manufacturer of your laminate flooring to make sure the specific cork you have can be used with your product and if that will be enough cushion.
Such an informative article and it is beneficial for many people, keep up the good work. Thank you so much for sharing.
Thank you for sharing this topic: “Can I install underlayment under laminate with attached padding?” I had fun reading about Vapor Barriers that you included. I look forward to hearing from you if there is a need for information about recessed aluminum floor doors for your following content.
Reolaced condo carpet in bedroom with Golden Select laminate flooring purchased from Costco. The information was that it has a 2mm foam backer to help with comfort, and create an extra sound barrier so no additional layer was required. It does indicate in the installation manual that, “for additional acoustical properties an additional underlayer of up to 2mm can be installed”. The flooring planks were installed as is without that additional underlayer and the neighbours downstairs are complaining of being woken by our walking. The condo specs are IIC 70 but I can’t see anything anout that impact sound insulation rating anywhere to compare the Golden Select vinyl planks to the standatd requirements. Are you familiar with this product? I’m not sure since the planks already have a 2mm foam backing if that is the same as the 2mm underlayer. I do wish the instructions had indicated the sound barrier underlay might be necessary if installing in a condominium
Hi Helen. We are not particularly familiar with this Costco product. We always recommend reaching out to the manufacturer to see if there is a particular product to help with noise reduction. However, we like to recommend a closed cell foam underlayment to help with the noise reduction. Floor Muffler has the highest ratings that we carry.
On the second level of my home, can I install cement backer boards over an OSB subfloor? If yes, can I still install LVP with the pre-attached underlayment on top of the backer board?
Lastly, I have a concrete slab on my first floor. Do I need a plastic sheet type vapor barrier over the slab before installing LVP with pre-attached underlayment or is the pre-attached underlayment sufficient (it’s a waterproof LVP)?
Thanks!
Hi Marc! Yes, you would be able to use cement backer board over OSB. You would also be able install a LVP with attached underlayment over the backer board without a vapor barrier.