Underlayment is an important step for any laminate flooring installation. There are several factors you will need to consider when choosing an underlayment. Learn more about what you should know before buying a laminate flooring underlayment.
What Is Flooring Underlayment?
It is a thin foam pad, often made of polyethylene or polypropylene, which is laid on the sub-floor before installing the laminate. Most laminate floors on the market today require an underlayment to be installed. While there are manufacturers who offer floors with an underlayment attached, this is a special feature and is not included with all products.
Why is Flooring Underlayment Necessary?
Laminate flooring is not nailed or glued down, so it needs some form of cushion between the subfloor and laminate to allow it to float easily. Think of it like a large jigsaw puzzle, which will be expanding and shifting as the climate changes. To avoid any damage due to friction between the laminate and your sub-floor, the underlayment must be laid first to give the laminate a smooth surface on which to float.
Which Underlayment Should I Use?
While the concept of underlayment seems simple enough, all laminate underlayments are not created equal. Different manufactures offer many different features, which can enhance the feel and performance of your laminate floor. To help you figure out which underlayment will meet your needs, we have put together some more information on the underlayments that we offer. Before reading on, first ask yourself these two very important questions:
1. What Is Your Sub-floor?
If you are installing laminate over a concrete sub-floor, it is very important that a vapor barrier is used to prevent any possible damage due to the moisture released by the concrete. This is simply a sheet of thin plastic material, like Visqueen Vapor Block, that will stop any moisture from being absorbed into the laminate core. Many of the underlayments from Bestlaminate offer 2-in-1 or 3-in-1 underlayments, which include a vapor barrier as well as padding. This saves you the time and money associated with installing a separate vapor barrier.
If you are installing over a wood or existing subfloor, you will not need to worry about a moisture barrier underlayment. Unless you require other properties, such as sound reduction, a standard foam underlayment will work for your project.
2. Is This A Second Floor Installation?
If you are installing your laminate floor in an apartment, condo, or on the second floor of your home, you may want to consider an underlayment that offers noise reduction. Many apartments and condo associations require a minimum sound rating from the underlayment. While laminate flooring is quiet to walk on, noise can easily be transferred to the floor below without the proper underlayment. Choose an underlayment, like Floor Muffler or Roberts Super Felt, that will give you a high sound reduction rating.
Floor Muffler Ultraseal 2mm Underlayment
What If My Laminate Has Pre-Attached Underlayment?
If your laminate flooring already has underlayment attached, you would not use another underlayment. Adding extra padding will put stress on the locking system and could cause your locking systems to break. The underlayment attached is meant to save you time from installing underlayment.
The exception to this rule is if you are installing above a concrete sub-floor. Attached underlayments will generally not have an included vapor barrier. You can install a thin vapor barrier that does not have extra padding to keep moisture from damaging your floor.
If you’re looking for a higher end underlayment with thermal or sound reducing properties, we would recommend finding a floor without attached underlayment and buying a higher quality underlayment for your needs.
Underside of Laminate Flooring Showing Attached Underlayment
Important Underlayment Terms
When reading the specifications of underlayment, you may come across terms like IIC and R-Value. These terms may leave you scratching your head, but don’t worry! Here are the most common underlayment terms explained:
STC & IIC
While looking at underlayment for your laminate floor, you may come across STC/IIC with a number next to them. What exactly are these and what do they mean? Put simply, these are ratings that tell you how well the underlayment will dampen sound. The higher a number is following these letters, the less noise will be transmitted. The effect of this is mostly noticeable in rooms underneath the room in which the underlayment and laminate are installed. This is why many apartment buildings, commercial offices buildings, and condo associations require a minimum rating where sound is concerned.
The Sound Transmission Class (STC) and Impact Isolation Class (IIC) ratings are measured in decibels reduced for certain types of sound. The STC rating pertains to airborne noise, such as voices, radio, television, etc. The IIC rating measures impact sounds, such as footfalls, dropped objects etc. The transmission of these sounds through floor/ceiling assemblies (such as those found in multi-level homes and apartments) will be inhibited by underlayments with higher STC and IIC ratings. The International Building Code (IBC) states that all multi-family buildings must have a minimum sound insulation rating of STC 50 and IIC 50.
Thermal Ratings
In addition to the STC and IIC ratings, some underlayments may also have a thermal rating, or R-value. 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.
R-values are measured in ft2*°F*hr./BTU, where °F is equal to the difference in temperature (in degrees Fahrenheit) between one side of a material and the other. An underlayment which has a value of 3 ft²*°F*hr./BTU will typically be represented as R-3. To put this in perspective, the typical R-value of a bat hitting fiberglass insulation is R-3 to R-5. Many polyethylene foam products have an R-value of 2-3, such as laminate flooring underlayments.
The Different Types Of Underlayments
Basic Underlayments
First up is our series of basic underlayments. These are the most simple, cost effective underlayments we offer at Bestlaminate. All three of our basic underlayments are suitable for most installations, though they do not offer many features. These are the most popular choices with contractors, due to their low price and effectiveness in allowing the laminate floor to float.
Standard Underlayment
The most basic option will be the standard underlayment. This is a great option for installing over plywood, oriented strand board (OSB) or existing sub-floors, where a moisture barrier is not required. The Standard Underlayment will absorb minor imperfections in the sub-floor, giving your laminate floor a smooth, even surface on which to float.
Standard Underlayment
2-in-1 Vapor Underlayment
Bestlaminate’s 2-in-1 Vapor Underlayment is another great option for basic installations. Made from the same low-density 3mm polyethylene as our standard underlayment, the 2-in-1 has the added protection of an attached moisture barrier film. This makes it a safe choice for installing your laminate floor over concrete sub-floors. Like the Standard Underlayment, this material will fill minor imperfections in the sub-floor, giving your laminate floor a smooth, even surface on which to float.
2in1 Vapor Barrier Underlayment
3-in-1 Vapor Underlayment
The third option in Bestlaminate’s series of basic underlayments is the 3-in-1 Vapor Underlayment. Another polyethylene foam, this one is only 2mm thick, making it better to use under thinner planks. Unlike the Standard Underlayment and the Vapor 2-in-1, the 3-in-1 comes in pre-packaged rolls of 100 ft². This underlayment has an attached vapor barrier and the added feature of an adhesive strip.
Vapor 3-in-1 Blue Underlayment
All of these underlayments are low density polyethylene. While none of them have been subjected to sound or thermal testing, they do offer some sound reduction, and are suitable to use over radiant heating. The Standard Underlayment and 2-in-1 Vapor Underlayment do not come in pre-packaged rolls, and can be cut for custom orders, making them a great choice for anyone who does not want to purchase an extra roll to get that few extra feet2.
Silent Collection
Next up is our series of silent underlayment. These are the next tier in underlayment that we offer at Bestlaminate. All five of these silent underlayment are suitable for most installations where sound dampening is key. Some of these underlayment also have vapor barriers attached, so be sure to look for these as you will get more bang for your buck if you’re installing over concrete subfloors. These are the most popular choices for people living in multi-family homes or apartments, or those who don’t want to hear their children playing around upstairs.
3-in-1 Silent Vapor Barrier Underlayment
If you’re looking for something that will help to muffle sound, but won’t break the bank, the 3in1 Silent Vapor Underlayment by Feather Step™ is a great option. This incredibly durable underlayment is a 2mm, cross-linked polypropylene, giving it a higher density than the open-cell polyethylene foam underlayment. Because of this, the Feather Step™ Vapor 3-in-1 absorbs sound and offers enhanced moisture protection. The attached foil moisture barrier works in conjunction with the foam itself to ensure that your floor is protected from any vapor given off by the sub-floor. This underlayment includes an adhesive strip for easy installation.
Feather Step 3-in-1 Vapor Barrier Silver Underlayment
ProVent Silent Vapor Barrier Underlayment by Kronoswiss®
ProVent Silent Vapor Barrier Underlayment is one of the best values where laminate flooring underlayment is concerned. This polyethylene foam is 3mm thick and comes in pre-packaged rolls of 215 ft2. An attached vapor barrier protects against moisture, but it doesn’t stop there! ProVent underlayment is specially designed with micro ridges that, when walked on, actually pump moisture out to the sides of the room to vent out moisture. This underlayment is a great choice for any job, including basements, first or second floor, apartments or condos. The Kronoswiss® ProVent can be installed over any type of sub-floor, and will absorb minor flaws, giving your laminate the proper surface to float.
ProVent Silent Vapor 3-in-1 Underlayment
Roberts® First Step ™
The First Step™ underlayment from Roberts® is one of the most popular choices in the laminate industry. Another great option for muffling sound, the Roberts First Step has an air flow layer which is similar to the Kronoswiss® Pro Vent. Polystyrene beads are substituted for a foam pad, allowing air to move freely through the underlayment to vent- preventing harmful mold and mildew build-up. This patented design also allows heat to be easily conducted, making this an excellent choice for sub-floors with radiant heat systems.
Roberts Silent 3 in 1 Vapor Underlayment
Floor Muffler® Ultra Seal
The Floor Muffler underlayment is the top of the line for sound reduction, with the highest STC/IIC ratings on the market. This makes it the number one choice for multi-family buildings around the globe. Similar to the Feather Step™ vapor 3-in-1 underlayment, the Floor Muffler® is made of a cross-linked polypropylene to give it more density. This directly contributes to its ability to cut down on unwanted noise. This also helps to block moisture, though it does not have a vapor barrier attached. The density of the Floor Muffler® underlayment keeps out any vapor released by your sub-floor, making it a safe choice to install over concrete subfloors.
Floor Muffler Ultraseal 2mm Underlayment
Roberts Super Felt Premium Underlayment
Roberts Super Felt Premium Underlayment provides you with superior sound dampening, insulation and a vapor barrier. This is a superior choice for installation of laminate and engineered wood flooring. This underlayment is available in convenient rolls containing 100 sq. ft. or 360 sq. ft. each. Durable and easy to install, this underlayment comes with a tape strip to easily seal the rows of underlayment together.
Other Products
Visqueen – Vapor Block PE Film
Visqeen PE Vapor Block PE Film is not an underlayment, but simply a vapor barrier sheet that may be used as on concrete sub-floors. This is the perfect option if you are laying a floor which has a pre-attached underlayment on a concrete slab or any other stone floor where there is potential for moisture.
Visqueen 6Mil PE Vapor Barrier
Along with the underlayment listed above, we have many more options for your laminate flooring underlayment. You can view all of our underlayment here.
How To Select Laminate Flooring Underlayment
Installing Underlayment
Each underlayment is a little different and has their own manufacturer instructions. You must read the instructions to fully get an understanding on how to properly install. We’ve prepared a variety of installation tutorials that will give you graphical step-by-step guides on how to install your underlayment.
View them here: Flooring Underlayment Tutorials
Do you have more questions? Simply post it in our comments area. We will be happy to answer them all!
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Learn More:
- How Much Underlayment Do I Need to Buy?
- Installing Underlayment With Laminate Flooring on Stairs
- Can You Put Down Two Layers of Laminate Flooring Underlayment to Reduce Noise Pollution?
156 comments
I am having a laminate floor install on concrete … here in Las Vegas, NV. What are your thoughts about Roberts AirGuard 5-in-1, QuickWalk and QuickWalk Plus? Which do your think is best for my application?
Thank you for your question, Larry. We would suggest using a 3-in-1 underlayment with an attached vapor barrier. Here is a good choice.
W have a really old frame house on pier & beam, and have replaced the bathroom floor with two layers of standard 3/4″ plywood. We want to install vinyl laminate. I know we have to use underlayment, but my concern is – do we need to install some type of vapor barrier under the underlayment – between the wood floor and the underlayment? I am concerned that without it, water could seep between the edges of the vinyl laminate pieces, through the underlayment and damage the plywood subfloor. Can a 6 mil layer of visqueen be used? Or what else can we do?
Thanks for your question, Hershel. Unfortunately, we are unsure of the product you are using making it tough to give you advice. Vinyl and laminate are two different products; vinyl is 100% waterproof and laminate is water resistant- not waterproof. We always recommend using vinyl in bathrooms as opposed to laminate for the waterproof qualities vinyl has. If you are using a vinyl with attached underlayment, you can use Visqueen over the subfloor for a vapor barrier. Moisture will not seep between planks that are locked properly.