How To Install Underlayment For Laminate Flooring On Concrete

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Last updated on October 21st, 2022 at 01:34 pm

How To Install The Moisture Barrier For Laminate Flooring Over Concrete

Ready to install underlayment for laminate flooring on your concrete floors and want to make sure you do it right? I’ve got you!

We installed laminate flooring through 80% of our home (which has an old, uneven concrete subfloor). So let me walk you through the steps we took to prepare our concrete floor for underlayment.

To install underlayment for laminate flooring on concrete, you need to:

Level the floor with self-leveling underlayment
Roll out the underlayment along the longest wall of the room
Cut the roll along the end wall
Roll out the next row and tape it to the first row
Cut around any obstacles
Roll out and tape the rest of the rows

I’ll further explain the steps below and add some pictures or videos to help you better understand the process. Soon, you’ll have gorgeous new laminate floors as well! How exciting!

Let’s dive in!

What Is The Best Underlayment For Laminate Flooring Over Concrete?

Before we start, let’s briefly discuss the type of underlayment you’re going to install.

Underlayment is extremely important for laminate flooring over concrete for a variety of reasons including acting as a moisture barrier, sound barrier, and cushion support.

Because it’s important to get an underlayment that has all of these qualities, I wrote a full article on what you should look for when choosing underlayment (and which is the best one specifically for laying laminate on concrete).

You can check out my helpful guide here.

Alright, let’s get into the actual installation.

Quick Navigation: Preparing A Concrete Floor For Laminate

Level The Floor With Self-Leveling Underlayment
Roll Out The Underlayment Along One Wall Of The Room
Roll Out & Tape The Next Row
Other FAQs About Laying Underlayment For Laminate Flooring
Final Thoughts
Related Laminate Flooring Articles

Level Of Difficulty	Time To Complete
Easy	1-2 Hours

Material List	Tool List
QuietWalk Underlayment	Utility knife and extra blades
Underlayment tape

Step One: Level The Floor With Self-Leveling Underlayment

The first step to installing underlayment for laminate flooring on concrete is to level the floor with self-leveling underlayment (concrete).

This step is probably the most important because if your floor isn’t level, then your laminate flooring is going to creak or break down over time.

To do this right, you need to lay a 4-foot level out across your floor and see where there are any valleys or peaks across your floor.

If the level rocks then that means there’s a high point in your floor, and if there’s a gap under the level then that means there’s a low point in your floor.

Either way, you need to mix this self-leveling underlayment found at Lowes until it is a pancake consistency and pour it across the uneven concrete subfloor. (This self-leveling underlayment is awesome because it doesn’t require a primer and can be poured directly onto green concrete. Definitely a huge time saver!)

It’s self-leveling, so it will naturally fill in the low areas and level out, but you might need to use a trowel to push it around to make sure it finds all of the low spots.

Here is a fantastic video that helps you see what I’m talking about.

Once your floor is level, it’s time to use the roll of underlayment!

Step Two: Roll Out The Underlayment Along One Wall Of The Room

The next step to installing underlayment for laminate flooring on concrete is to roll out the underlayment along the longest wall in the room.

To do this, put the flap against the wall and have the sticky side opposite the wall. (You can cut off the flap with a sharp utility knife on the first row if it keeps getting in your way.)

how to install underlayment laminate flooring concrete - start on one wall — The key to doing this fast is having a sharp utility knife with extra blades. Concrete dulls the blades quickly which makes cutting underlayment significantly harder. Just swap the blade out when it gets dull and keep moving!

Roll it out until you reach the opposite wall, then cut it off with a sharp utility knife so that it is flush with the wall.

(If you don’t have enough in a roll to reach the opposite wall, thats fine. Just roll it out as fas as you can, and start the next roll where the last one stopped.)

how to install underlayment laminate flooring concrete - cut with utility knife — When we couldn’t reach a wall to end on, we’d use tape to connect the two separate pieces together and keep them secured.

That’s it for the first row! Now, let’s move onto the next row.

Step Three: Roll Out & Tape The Next Row

The next step to installing underlayment for laminate flooring on concrete is to roll out and tape the next row.

Repeat the same process from step 2 where you roll out the row with the flap toward the sticky side of the first row and cut it off against the opposite wall.

Then, go back to the first row and peel off the protective coating over the sticky part, and lay the flap from row 2 onto the sticky part of row 1 to hold the two pieces together.

how to install underlayment laminate flooring concrete - tape the seams together — Starting with the flap against the wall makes the taping process so much easier.

Do you tape down underlayment?

Underlayment should be taped down to prevent bunching underneath laminate planks over time and to create a sealed moisture barrier between the laminate flooring and the subfloor.

If there isn’t a flap and sticky side to seal two pieces together (such as if you ran out of a roll before reaching the opposite wall and needed to start another roll), then use underlayment tape or duct tape to seal the underlayment together and create a moisture barrier.

The underlayment does not need to be glued, taped, or stapled to the concrete subfloor, however.

It can be free-floating, and as long as the individual pieces are taped together, it will protect the laminate flooring from moisture, create a sound barrier, and add extra cushion and support while you walk on it.

You will continue this process until the entire floor is covered!

How To Install Underlayment If Your Room Is Not Square

If you run into a half wall or a corner of the room that sticks out, then just use your utility knife to cut around the obstacle.

The goal is to get the underlayment flush with all of the walls. Otherwise, a gap in the underlayment can create an uneven floor and again, make your laminate flooring creak or break down over time.

Keep repeating the process until the entire concrete subfloor is covered with underlayment and all of the underlayment pieces are taped together!

how to install underlayment laminate flooring concrete - before and after — This was a big space to do, and we still knocked it out within an hour or two!

Other FAQs About Laying Underlayment For Laminate Flooring On Concrete

Here are some other frequently asked questions about laying underlayment for laminate flooring on concrete. These answers will help you install your underlayment fast and efficiently!

Can Duct Tape Be Used For Underlayment?

Duct tape can be used to seal the seams of underlayment. Sealing the seams of underlayment for laminate flooring helps create a moisture barrier and prevents the underlayment from bunching underneath the laminate flooring as it is walked on over time.

For most of our underlayment installation, we used underlayment tape, but there were a few spots where we ran out of underlayment tape and just used the duct tape we had on hand.

Final Thoughts On Preparing A Concrete Floor For Laminate

There you have it! The most important part of installing underlayment for laminate flooring is ensuring that the concrete subfloor is level first.

After that, installing the actual rolls of underlayment is a breeze!

Catch you in my next post!