In our laminate flooring installation guide we give clear information on the tools and techniques you’ll need to get the job done. Of course there are specific instances where you will need to take further factors into account and installing laminate on concrete is one of those situations.
Laying laminate flooring over concrete can look great and last for many years when installation factors involving the characteristics of concrete are addressed.
The Challenges of Laying Laminate on Concrete
For long-term performance your laminate wood floor needs to be dry, level and clean. These are the challenges. Let’s start with the moisture problem.
Protecting Laminate Flooring from Moisture
Concrete is extremely hard, so homeowners might mistakenly believe it is impenetrable. The fact is that moisture vapor passes through a concrete slab rather easily. Here is how to keep it from penetrating into your laminate flooring to cause warping and declamation.
Allow new concrete to cure for 30 days minimum: Whether it’s a basement slab, self-leveling concrete containing radiant floor heating or other concrete installation, the material must be allowed adequate time to give off excess moisture.
Check the humidity level of basement slab concrete: Once the concrete has had time to cure, check humidity with a moisture meter, and if it is 4.5% or higher, the slab might be unsuitable for laminate, even with a vapor barrier. Check the specifications on the flooring you’ve selected for moisture tolerance.
If you don’t have a moisture meter, cut a 2’x2’ square of plastic, and tape it to the floor being careful to seal all four sides. If moisture accumulates beneath the plastic in 2-3 days, it’s not a good environment for laminate flooring. We should note too that if your basement is prone to flooding, laminate is on the list of poor flooring choices that includes carpeting, solid hardwood and engineered hardwood and we don’t recommend that you attempt to install it over concrete.
For excellent flooring choices for moist/wet areas, see Waterproof Basement Flooring – Best Options,
Installation and Cost
Install a plastic vapor barrier: If your concrete passes the moisture test, then plastic sheeting at least 6 mils thick will prevent moisture from getting into your laminate flooring. Where plastic sheets must be joined, overlap the sheets by several inches, and use strong vinyl tape to secure them. The vapor barrier will also prevent radon gas from penetrating the slab, an added benefit.
Vapor barrier material costs: The cost of 6 mil plastic sheeting ideal for use as a vapor barrier costs just $0.08 to $0.12 (8 to 12 cents) per square foot. The cost of strong vinyl tape for securing plastic at the edges and for taping sheeting together is about $0.20 (20 cents) per linear foot.
Providing an Even Surface for Laminate
Dips or bumps beneath laminate flooring will cause the flooring to squeak or to quickly come apart, so they must be eliminated.
Fill low spots with patch or self-leveling concrete: Cracks more than ¼” wide, gouges and large chips should be filled with patch. Dips, such as where the slab has cracked and settled unevenly in a corner, should be corrected with self-leveling concrete.
Both products are inexpensive ($15/gallon for patch; $40/50lb bag for leveling concrete) and easy to use. Pick some up at your local home improvement store, and follow directions carefully. Patches and small sections of self-leveling concrete need just a few days to cure.
Sand down bumps: Concrete bumps from poor flatwork finishing, adhesive from old flooring and other raised imperfections must be removed. A hammer and chisel can be useful for small bumps; a grinder is the best tool for larger high spots. A power sander or hand sander is ideal for removing non-concrete materials.
If the concrete slab is in very poor condition, the best practice is to use a grinder or buffer with a concrete scraper over the entire surface before covering it with a layer of self-leveling concrete.
Clean the Floor for Glue-down Installation
Using a glue-down floor is an option in above-grade installation only since installation below grade requires a plastic barrier on top of the concrete.
For the floor adhesive to properly stick, the floor must be clean. Use a quality cleaner like Zep Professional Concrete and Masonry Floor Cleaner ($27 per gallon; 500-750 square feet of coverage).
Add Padding for Comfort
Concrete is very hard, and laminate isn’t much softer. Adding a layer of laminate padding on top of the moisture barrier will make a noticeable difference in how comfortable the floor is to walk on. The laminate floor padding cost is $0.12 to $0.15 (12 to 15 cents) per square foot. Padding can be used with most floating laminate floor installation.
Installing Laminate Flooring on Concrete Steps
If you’ve got concrete stairs to cover, the laminate must be glued down using high-quality construction glue. A floating installation is not secure enough for stairs, and flooring coming loose might lead to falls. No vapor barrier or padding should be used. Practice the tips given here to prepare the concrete.
Use Standard Installation Practices for Laminate
Once the concrete is prepped, proceed with installing the laminate on top as you would over any other type of subfloor. As well as our laminate installation guide you may also want to read our guide on how to cut laminate flooring if you plan to do the work yourself. If you decide to leave installation to a professional, we can help you receive written estimates from three of the top flooring installers where you live. The service is free and convenient, and there is no obligation.