When it comes to underlayment products, you probably have a lot of questions, which is why we created this underlayment guide! What kind do I need? How much do I need? Is it mandatory to install underlayment with your flooring? What if you have special floors, such as those with radiant heat or in wet environments?
At BestLaminate, we hear questions like these all the time. Floor underlayments can make a huge difference in your installation, so it is important to know which flooring underlayment is best for your needs.
When preparing for your flooring installation, you will need to consider what type of characteristics and protection you need in a flooring underlayment. Although it might seem overwhelming at first, as you get to know more about various types of flooring underlayments, the decision will become easier.
Why is Flooring Underlayment Needed?
Think of flooring underlayments as the protective barrier between your floating flooring and subfloor. This is the layer that keeps moisture away from your floating floor, reduces noise pollution when walking on your new floors, provides a soft cushioned step, and can help smooth out some subfloor inconsistencies.
It is a necessary component of any laminate flooring or floating engineered hardwood installation.
Flooring underlayment works as a thin foam pad to protect your flooring. Laminate flooring floats above your subfloor. It is not glued or nailed down, making installation and repairs easy. When you install laminate flooring, you put it together like a puzzle. That way, when the flooring expands and contracts from changes in the temperature and moisture, your flooring moves together as one unit. The foam underlayment provides a barrier from friction and other damaging threats when it shifts.
Underlayment Needs Per Floor
- Laminate – Laminate flooring ALWAYS needs foam underlayment. Options range from standard padding to noise and moisture reducing options.
- Pre-Attached Laminate – Some laminate flooring comes with foam underlayment attached. In this circumstance, you do not need additional underlayment. If you are installing over a concrete subfloor, you can add a vapor barrier film.
- Click-Lock Vinyl – Vinyl flooring does not need flooring underlayment. Most vinyl warranties will be voided if an underlayment is used. If you’re worried about moisture from your subfloor, you can install a vapor barrier film, or look for a specific vinyl flooring underlayment that is thinner than a standard laminate foam underlayment.
- Engineered Hardwood – Engineered Hardwoods can be floated, glued, stapled or glued. When installing a floating floor, you will need a foam underlayment. When gluing your engineered flooring, you will need a hardwood adhesive.
- Hardwood – Hardwood floors are nail or stapled down to the subfloor. Hardwoods can use an asphalt underlayment, floor muffler or just a vapor barrier.
Types of Underlayment
There are a variety of underlayment products to choose from, which surprises many people. The basic types of floor underlayments include:
- Standard Foam Underlayment – This is the most basic type of underlayment available. It is best used on plywood or OSB subfloors where moisture is not a factor. Use this if there are few imperfections to your subfloor.
- 2 in 1 Vapor Underlayment – This is ideal for basic installations. It is made up of 3mm polyethylene underlayment. The combination includes a standard layer and a moisture barrier. It is ideal for basic installations.
- 3 in 1 Vapor Underlayment – This is a 2mm thick underlayment, which is ideal for thin floors. With the 3-in-1 vapor underlayment you get protection against moisture, some sound, and minor subfloor leveling.
- 3 in 1 Silent Vapor Barrier Underlayment – The silent collection of underlayment includes protective layers that dampen the sound when walking on the floors. There are many brands and varieties to choose from in this category.
- Vapor Block Film – This is used to block moisture. It is only suitable for flooring where underlayment is pre-attached, under a vinyl or hardwood floor. You can also use this in conjunction with another underlayment if you would like.
- LVT Underlayment – A vinyl underlayment solution is thinner than a typical wood floor underlayment, generally under 2mm. These can have sound and cushioning properties. Always check your vinyl manufacturer flooring instructions to determine if an underlayment is advised or not.
- Cork Underlayment – This is a natural, hypoallergenic underlayment that is suitable for WPC vinyl, laminate and click-lock engineered hardwood. It prevents moisture, mold, mildew, offers thermal properties and cushion.
- Asphalt Underlayment – This is a commercial and residential grade underlayment suitable for hardwood and tile floors. It is the most effective underlayment for moisture prevention with these types of floors.
With so many varieties to choose from, you might not be sure which one is right for your new floors. Continue reading on how to select the right underlayment for your flooring project.
How to Choose Flooring Underlayment
There are a few factors to consider when you’re shopping for a foam underlayment for your flooring, whether it’s a laminate or engineered hardwood. Here are a few important factors to take into consideration.
Type of Subfloor
The type of subfloor makes a difference in your flooring underlayment.
- Plywood: A plywood subfloor will not need as thick or sturdy of underlayment as concrete. You generally will not need to worry about a vapor barrier with this subfloor.
- Concrete: A concrete subfloor is porous and can hold moisture. It is recommended to use a vapor barrier underlayment with concrete subfloors to prevent any moisture coming up from the subfloor.
Location, location, location
If you are installing your floors in a condo or apartment, sound is a big concern. This is especially true if your apartment or condo is above the ground level. To reduce noise pollution for the neighbors below you, opt for a 3-in-1 underlayment and look for the Sound Transmission or Impact Isolation ratings. You may also be required by your HOA or lease agreement to have a foam underlayment with a particular sound rating.
Sound Transmission Class (STC) ratings and Impact Isolation Class (IIC) ratings are used to determine how many decibels and types of sound the foam underlayment can help reduce. STC ratings determine airborne noises and IIC ratings measure the impactful sounds, such as footsteps and drops. Consider these sound ratings for commercial or apartment buildings.
Your underlayment might also have a thermal rating. This is also known as an R-value. The R-value or thermal rating determines how well a flooring underlayment can conduct heat. The higher the value, the less heat will run through it. This is important for homeowners with a radiant heat system.
Step By Step Guide to Choosing Flooring Underlayment
Buying Your Underlayment
Finding the right type of flooring underlayment might seem confusing at first. By considering location, subfloor, sound, and heat levels, you can find the perfect underlayment for your needs.
Questions about flooring underlayments? Still not sure which one is right for you? Contact one of our flooring experts. for more help in making your decision.
NOTE: The tips provided here are only intended to guide your installation. You should ALWAYS follow the instructions provided by the manufacturer.
Depending on which foam underlayment you purchased, there will be slightly different installation instructions per manufacturer. By properly installing your flooring underlayment, you will protect your floors for years to come. Save money and install it yourself!
Some companies even warranty their flooring underlayments for your peace of mind! Below, we have listed the detailed manufacturer warranties for selected underlayment. Some warranties are also listed in the description on our product pages. Be sure to read your warranty carefully so your foam underlayment will be protected for years to come!