Dear Bob and Betsy,
I live in northern Michigan and it can get cold in the winter. Can I use underlayment under vinyl flooring as insulation to keep my house warm? If so, what kind of underlayment is best?
Thanks! Silvia O.
BRRR! Winters in Michigan don’t sound fun! We can understand why you would be concerned with warmth and insulation in any place you can get it. There is some good news and bad news when it comes to underlayment and vinyl flooring. We have compiled more information for you to help to decide what’s best for you. Cheers! Bob & Betsy
Do I Need Underlayment for Vinyl Plank Flooring?
Underlayment is a popular option under many types of floating floors to help with warmth, cushion, sound, and smoothing subfloor irregularities. The rule for vinyl flooring used to be that underlayment should not be used, due to the unstable and flexible structure of LVT, however, you can find engineered core vinyl now that are allowed to have underlayment due to the stability of the planks.
No matter the type of vinyl flooring chosen, it needs to have a sturdy, stable sub-floor with very little cushioning regardless of the installation type. Even today’s engineered vinyl should only have an underlayment of 1mm or less thickness. When choosing a standard LVT, not needing underlayment is both a savings in your pocket and time with installation, however, this means no thermal insulation.
Vinyl Flooring with Attached Underlayment
With today’s technology, you can find many vinyl floors that come with attached underlayment, usually 1mm or less. These floors are typically engineered core vinyl (*insert article about this) with more stability than classic LVTs. These will be referred to WPC, SPC, Engineered Core or Hybrid. If you’re looking for a warmth factor, you will need to look up the manufacturer specifics on the underlayment attached.
R-Value for Warmth
Standard laminate and engineered wood flooring underlayment will have sound and thermal ratings. These are STC, ICC and R-Value. You will want to look for the R-value if you are investigating an attached vinyl underlayment for warmth. This refers to the underlayment’s ability to conduct heat.
The higher an R-value is, the less heat will move through it. Many homeowners prefer an underlayment with a higher R-value to keep their feet warm in the winter months, however, if you have any kind of radiant heat system, a high R-value can inhibit its effectiveness. Learn more about R-Value here.
Type of Subfloor
When it comes to warmth under your foot, a subfloor will also play a role. If you’re installing over a concrete subfloor, the flooring will generally be colder than a wood subfloor. If you’re installing over a concrete subfloor, we’d recommend going with a thicker vinyl that has attached underlayment. If you’re open to another type of floating floor, like laminate, you would be able to get a thicker underlayment with R-Value.
No Thick Underlayment Under Vinyl Flooring
Unfortunately, adding insulating underlayment under vinyl flooring will cause the flooring to be unstable. Because vinyl flooring isn’t made from wood products, it does not have the same structure that laminate flooring does. Vinyl flooring needs to have a sturdy, stable sub-floor with very little cushioning regardless of the installation type: glue-down, click-lock, or loose lay. However, if you are installing vinyl flooring over a concrete sub-floor, you will need a very thin vapor barrier, such as Visqueen Vapor Barrier underlayment to protect your flooring from moisture.
If You’re Set On Having Insulation Under Your Floor…
If you are set on having the warmth and insulation under your flooring, we would suggest switching to laminate flooring. Laminate flooring has to have underlayment in order to float the flooring. There are lots of different underlayment to choose from for your specific needs. If you’re looking for insulation, we recommend Robert’s Super Felt Premium Underlayment. The felt adds lots of insulation and sound dampening properties that will keep you warm and your floors quiet!
Do you still have questions about vinyl flooring or underlayment? Feel free to comment in the space below and we will be happy to help!