How to lay laminate flooring on concrete floor
To lay laminate flooring on concrete, prepare the subfloor by ensuring it’s clean, dry, and level. Install a moisture barrier and underlayment. Then, click the laminate planks together according to the manufacturer’s instructions, leaving expansion gaps around the perimeter.
Laying laminate flooring over a concrete subfloor is a common and achievable DIY project. Concrete is a stable base, but it requires careful preparation to ensure your new floor lasts. The key steps involve ensuring the concrete is level, dry, and free from contaminants, followed by installing a moisture barrier and underlayment before clicking the laminate planks into place.
Before you begin, gather your tools and materials. You’ll need laminate flooring planks, underlayment, a moisture barrier (if required by your laminate manufacturer or if the concrete is below grade), a measuring tape, a utility knife, a tapping block, a pull bar, a rubber mallet, a pencil, a chalk line or straight edge, safety glasses, gloves, and a miter saw or jigsaw for cutting planks. Ensure you have enough planks for your square footage, plus an extra 10% for cuts and mistakes.
Prepare the concrete subfloor
The concrete subfloor must be perfectly clean, dry, and level. Sweep or vacuum up all dust, debris, and loose particles. If there are any old adhesives, paint, or sealers, remove them using a scraper or by grinding the concrete. Small cracks or chips can be filled with a concrete patching compound, allowing it to cure fully according to the product instructions. For significant unevenness, you may need to use a self-leveling compound. Check for moisture issues. You can perform a simple test by taping a 2ft x 2ft piece of plastic sheeting tightly to the concrete for 24 hours. If you find condensation on the underside of the plastic or the concrete appears dark, you have a moisture problem that needs to be addressed before installing laminate.
Install the moisture barrier
A moisture barrier is crucial, especially if your concrete is on or below grade, or if your laminate manufacturer requires it. Lay the plastic sheeting (typically 6-mil poly) over the entire subfloor, overlapping the seams by at least 6 inches and taping them with moisture-resistant tape. Run the barrier up the walls about 4-6 inches, as this will be trimmed later. This barrier prevents moisture from migrating from the concrete into the laminate, which can cause swelling, warping, or mold growth.
Install the underlayment
Over the moisture barrier, install the laminate underlayment. This usually comes in rolls or pre-cut pads. The underlayment provides cushioning, sound dampening, and helps to smooth out minor imperfections in the subfloor. Follow the manufacturer’s instructions for laying the underlayment, typically rolling it out and butting the edges together, or overlapping and taping as specified. Some underlayments have an integrated moisture barrier, which may allow you to skip the separate plastic sheeting if it meets the requirements for your installation.
Acclimate the laminate flooring
Laminate flooring needs to acclimate to the temperature and humidity of the room where it will be installed. Store the unopened boxes flat on the subfloor in the installation area for at least 48-72 hours, or as recommended by the manufacturer. This prevents the planks from expanding or contracting excessively after installation, which can lead to gaps or buckling.
Lay the laminate planks
Start laying the planks in a corner of the room, typically the left corner. The tongue side of the first plank should face the wall. You’ll need to cut off the tongue on the side and end of the first row of planks that will face the walls. Place the first plank with its back (the side without the groove) about 1/4 inch to 1/2 inch away from the wall to allow for expansion. Use spacers or shims to maintain this gap along all walls and fixed objects.
Connect the second plank to the first by angling its tongue into the groove of the first plank and lowering it. Continue this process for the entire first row. For subsequent rows, you’ll typically angle the long edge of the plank into the groove of the plank in the previous row, then gently tap it down with a rubber mallet and tapping block to ensure a tight fit. Some systems require you to connect the short ends first, then the long edges. Always refer to your specific laminate flooring’s installation guide.
When you reach the end of a row, you will likely need to cut a plank to fit. Measure the remaining space, subtract the expansion gap, and cut the plank. Use the cut-off piece to start the next row, provided it is at least 6-8 inches long to create a staggered or offset pattern. This staggering adds strength and visual appeal to the floor. Aim for offset joints of at least 6 inches between planks in adjacent rows. Continue laying rows, ensuring each plank is securely locked into the previous one, until the entire floor is covered.
Finishing touches and trim
Once all planks are laid, remove the spacers. Install baseboards and quarter-round molding around the perimeter of the room to cover the expansion gaps. The baseboards should be nailed to the walls, not the laminate floor, to allow for movement. Install transition strips in doorways or where the laminate meets other flooring types. Finally, cut and fit any remaining pieces around obstacles, ensuring expansion gaps are maintained. Clean the floor according to the manufacturer’s recommendations.
Common Mistakes When Laying Laminate on Concrete
| Step | Typical Mistake | Consequence |
|---|---|---|
| Subfloor Preparation | Not cleaning or leveling the concrete | Warping, squeaking, uneven surface, premature wear |
| Moisture Barrier | Skipping or improperly installing | Moisture damage, mold, mildew, buckling planks |
| Acclimation | Not allowing planks to acclimate | Gapping, buckling, or lifting planks after installation |
| Expansion Gaps | Not leaving adequate gaps around the perimeter | Buckling or lifting of flooring as temperature/humidity changes |
| Cutting | Incorrectly measuring or cutting planks | Poor fit, difficulty locking planks, wasted material |
FAQ
How to lay laminate flooring on concrete
Start by ensuring your concrete floor is clean, dry, and level. Install a 6-mil poly moisture barrier and then the recommended underlayment. Acclimate the laminate planks according to manufacturer instructions. Lay the planks, clicking them together and maintaining a 1/4 to 1/2 inch expansion gap around the perimeter.
How to lay laminate flooring over concrete
Prepare the concrete by cleaning, leveling, and checking for moisture. Lay down a moisture barrier, followed by the underlayment. Ensure the laminate planks have acclimated to the room’s environment. Begin installation in a corner, working your way across the room while maintaining expansion gaps against walls and obstacles.
How do I lay laminate flooring on concrete
You lay laminate flooring on concrete by first thoroughly preparing the subfloor. This includes cleaning, repairing any damage, and confirming it’s dry and level. Then, install a moisture barrier and underlayment before clicking the laminate planks together, always remembering to leave expansion gaps.