Laminate flooring is durable and affordable and can renew the floor of your home because it is easy to install over many materials, including concrete. However, there are some considerations, so it can be useful to truly know how to install laminate floors on concrete before beginning the project.
To install laminate flooring on concrete, you will first prepare the subfloor making sure the concrete is clean and even, using a concrete grinder and leveling compound when needed. Finally, install the underlayment and then the laminate flooring on top, leaving a ¼ inch expansion gap.
In this article, you will learn how to install laminate flooring over concrete and how to deal with some factors that you may come across like uneven concrete and whether you should use underlayment. You will also discover the best types of flooring to use for this purpose.
Can You Put Laminate Flooring Directly on Concrete?
You can put laminate flooring directly on concrete, but it is better to include an underlayment first. The main reason for underlayment is that concrete is porous and can hold a significant amount of moisture that can infiltrate the laminate. This can warp the floorboards or contribute to mold and mildew.
The underlayment can also help moderate between slight, seemingly insignificant cracks and crevices and the underside of the floorboards. The floor will be more durable and longer-lasting because it will be more even and uniform.
Another less significant issue with putting flooring directly on concrete without underlayment or dividing material is temperature and comfort. Concrete can get cold and make the flooring on top of it cold. Some underlayments and flooring types will not do much, if anything, for this problem, but some can take the temperature up a little.
So, you can’t just slap the laminate together on top of the concrete to avoid issues like these. It is important that you know what you are doing to ensure a long-lasting, attractive, and durable floor.
How to Install Laminate Flooring on Concrete
The main steps to install laminate floor over concrete are to acclimate the laminate floorboards to the room, prepare the area and concrete surface, install the underlayment, and then install the laminate flooring planks. Before looking at how to install the flooring over concrete step by step, it is good to have some knowledge about preparing the concrete floor.
Preparing Concrete Floor for Laminate
While laminate flooring works well on top of concrete, you do have to prepare it so that it will do well. There are several concerns to keep in mind before starting that you will want to consider before moving on to the step-by-step guide.
First is moisture, which is always a factor with concrete subfloors. Too much moisture could be detrimental to your laminate flooring project. You will want to test the moisture content before starting and ensure it is not higher than 4.5%.
Concrete can hold moisture for a long time because of the porous properties of the material. This is typically only a concern for around 60 days after installing the concrete. However, we still recommend getting an accurate reading using a standard moisture meter or Calcium Chloride Test even if the concrete is older than that because there could be areas that contain unusual amounts of moisture.
The second concern is whether the concrete is level enough to install flooring on top of it. Laminate is a floating floor, so any significant, or even insignificant, peaks and crevices can impede the locking mechanisms and destroy the stability of the flooring system. Therefore, the concrete subfloor should not have any substantial gaps or cracks.
If the concrete does have those types of imperfections, that is okay, but you will have to repair them before beginning the laminate installation process. You can lower peaks and level the flooring itself using a concrete grinder. You can also use a leveling compound to even out other spots and fill in crevices and other irregularities.
You want to make sure that any variations within a 10-foot radius are no larger than 3/16 inches. Anything over that variation one way or the other within 10 feet can be too rough and cause problems during or after the installation of laminate. You can use a long level to measure the variance accurately enough.
Many homeowners want to know if you need to seal a concrete floor before laying laminate and the answer is no. We highly recommend avoiding doing so because the sealer can make it harder for leveling concrete to bond with concrete.
Now that you know the intricacies of preparing concrete floors for a laminate installation, you can proceed to the steps for doing the project yourself.
What you need:
- Long Level
- Moisture Meter
- Concrete Grinder
- Self-Leveling Compound
- Laminate Flooring
- Underlayment Seam Tape
- Flooring Spacers
- Rubber Mallet
- Tapping Block
The first step is the easiest because it only involves acclimating the laminate plains to the room. Just store them in the room for 48 to 72 hours before continuing the installation. This allows them to adjust properly to the humidity and temperature conditions of the room.
As mentioned earlier, you have to prepare the concrete subfloor before continuing. The first part of this step is to make sure that the concrete is completely clean. Sweep away all the dirt and then use a shop vac to get the remainder of debris, dust, etc.
Then, you can go ahead and check the moisture content and use a long level to make sure that the subfloor is not too uneven according to the specifications listed in the section above (which we recommend you read before proceeding). The next step will detail how to make the floor even enough to move forward with the project.
To level concrete, you want to use a scraper first to get rid of any easily removable imperfections. Then sweep them up completely before moving on to the concrete grinding or leveling compound stages.
Leveling compound is best used for minor crevices, cracks, and gaps. Use a self-leveling compound and pour it over the areas where it is needed. To make it uniform, you can also apply ½ inches over the rest of the area. Then, spread it evenly over the floor with a squeegee.
For larger imperfections, you will want to use a concrete grinder. Just make sure you keep in mind that it will take off around 1/16 inches with each pass. This works well for concrete surfaces that are rough or have inclines.
The next step is to install the underlayment to prevent moisture seepage that can ruin the floor. Several types include foam barriers, vinyl-backed underlayment, and cork underlayment. We generally recommend a foam underlayment for these purposes, but you can read more about the best option for installing laminate on concrete later in the article.
Once you have your underlayment product, trim off the end of overlap and roll it in one direction. It is best to roll it in the same direction that you plan on aligning the laminate floorboards. When you reach a wall, you want to keep 2 inches excess that goes up the edge of the wall. This will be trimmed later.
When you go to the next row of underlayment, you will use the overlap to secure it. While many options have a peel and stick edge, if yours doesn’t, you will need to use seam tape. This goes for any seams and rips around the entire room. Seam tape is necessary because it also acts as a barrier to moisture.
Finally, you can install your new laminate flooring. We suggest starting the installation in the farthest corner of the room and moving away. Make sure that you leave a ¼ inch gap around the edge of the room (you can use flooring spacers) to allow room for expansion of the flooring.
With the first row, make sure you put the tongue side facing the wall. You will align the tongue into the groove with each piece and press the board down to snap it into place. They should lay down easily after doing so as long as your floor and underlayment are even enough.
When you get to the end of the first row, you will probably have to cut the plank at the expansion gap. You can cut pieces as needed using a jigsaw. It can be easier to measure and cut on the side without the tongue and groove.
Make sure you finish each row all the way to the expansion gap before moving on to the next row. Many people find the floor looks better if the planks are staggered, so you can start on the opposite side if you cut the last piece of the first row.
To lock the mechanisms and ensure a tight-fitting floor, you can also use a mallet and tapping block. While many floors do not require this, some do and as long as you are careful, it won’t hurt any of them and can ensure a tighter seal because it will help you engage the groove and tongue components.
The last row is often the most difficult because you may have to cut every piece to fit. However, it is the same as the other rows as far as actual installation is concerned. Once you complete the entire room, remove the spacers, cut excess underlayment, and put the baseboards back. Congratulations on your new floor!
Can You Install Laminate Flooring on Uneven Concrete?
You should not install laminate flooring on uneven concrete because it can cause the laminate floorboards to become damaged or degraded. The uneven concrete can cause the flooring to shift excessively and dips on the concrete will create a pocket of air under the planks, making them creak and echo. This can gradually damage the interlocking mechanisms, leading to gaps for separation and moisture instruction.
The uneven concrete can also warp the boards themselves, which causes some planks to lift over time. This can wear them away and force you to get a new floor before you get enough use out of the old one. It can also cause a tripping hazard if the boards raise too much.
So, unevenness isn’t good, but how smooth should the concrete be before installing laminate on top? In any 10 foot radius, you should not have any variation of greater than 3/16 inches. You can use a long level to measure the variance. If there are larger bumps and dips in a section, then just make sure that you grind those areas down or fill crevices using a leveling compound. It is not too hard to ensure the concrete is even enough and doing so will increase the lifespan and durability of your laminate floor.
Do You Need Underlay for Laminate Flooring on Concrete?
You need an underlay before laying the laminate flooring on top of concrete to avoid the risk of moisture penetration from the concrete. Moisture can damage the floor and cause warping in the planks and other issues like potential mildew and mold.
Some laminate flooring products will require underlayment for the warranty to be intact. If you do not want to void the warranty, then it is certainly something to check before considering installing the floor without underlay. It may also help reduce the harm caused by small bumps or cracks in the concrete floor.
Best Laminate Flooring for Concrete Slab
There are several types of laminate flooring to choose from, but they are not all as effective for use on concrete. Too thin laminate floors are not recommended for use with concrete because of the texture and potential for uneven areas, even if you substantially smooth the subfloor surface.
We usually recommend plastic laminate flooring over engineered wood laminate flooring for several reasons. While engineered wood can work great too and is often desired for its attractiveness, it can be more vulnerable to moisture penetration from the porous concrete.
Plastic laminate has several layers, one called the backer. This is the bottom layer that serves as a moisture barrier, so combined with the underlayment should completely prevent any moisture from infiltrating the flooring itself.
Furthermore, the middle layers are constructed using high-density fiberboard that can resist slight uneven portions of the concrete subfloor. This makes it more likely to be flexible even if you have variations nearing the maximum allowable before installing the laminate.
What is the Best Underlayment for Laminate Flooring on Concrete?
The best underlayment for laminate flooring on concrete is a foam rollout sheet made from polyethylene or polypropylene that serves as a moisture barrier. The rollout sheets are easy to install and effective for preventing seeping liquid from concrete to the layers of laminate.
Other types can work as well, but you always want to make sure that you get underlayment designed to be a moisture barrier since that is the primary concern when laying laminate flooring on concrete.
Combination foam underlayment that consists of standard foam and a vapor barrier layer is a little more expensive than standard foam. Still, it is very good for concrete, especially if the area is prone to moisture like a basement or bathroom.
Another thing to consider is the R-value, which represents the heat transfer of the flooring material. Concrete can get cold and make the room uncomfortable. Underlayment options with a high R-value will keep the flooring feeling warmer and may even reduce energy usage in the room.
Noise can also be an issue with laminate on concrete, but some underlayment options can reduce the transmission of noise. However, cork underlayment options are typically utilized for noise reduction over foam options and can be much more expensive.
One underlayment option we like for laminate flooring on top of the concrete is MP Global Products Flooring Underlayment with Attached Vapor Barrier because it is made to support the locking mechanisms and offers great moisture protection using recycled fibers. It is also quite easy to install.
Can You Glue Down Laminate Flooring on Concrete?
You cannot glue down laminate flooring to concrete because laminate is made as a floating floor that allows it to expand and contract. If it is glued down, it cannot do this properly, leading to deterioration and damage. Also, you cannot glue laminate to the underlayment and will likely run into some issues if you attempt to do so.
Laminate flooring is a fantastic choice for concrete subfloors as long as you know what you are doing. If the concrete is uneven, you will want to smooth it out before installing laminate on top and you will also need underlayment to prevent moisture from getting into the flooring planks. If you do it correctly, though, the laminate flooring should be durable and have a long lifespan.