What Do You Put Under Laminate Flooring?: A Designer’s Guide to Subfloor Prep, Underlayment & Mistake-Free Installation

If you’re getting ready to install laminate flooring, you’ve probably heard about the importance of what goes underneath. Trust me—as a designer and DIY coach, I’ve seen countless projects go sideways from ignoring this step. The secret to a quiet, comfortable, and long-lasting laminate floor isn’t just the boards themselves, but the right foundation beneath them.

Most U.S. homes have concrete slabs or plywood subfloors, but what goes between these and your new laminate is called underlayment—a thin layer that cushions, insulates, and controls moisture. Skipping or skimping on this layer can mean noisy floors, cold feet, or even expensive repairs from mold and warping.

Choose the Right Tools

When I help clients renovate their living room or upgrade a rental unit, I always start with proper assessment. A quick check for uneven spots, moisture, and old glue is critical. You’ll want a quality underlayment—rolled foam is the most common, but there are cork, rubber, and special vapor-barrier options for basements or rooms over crawl spaces. Some newer laminate boards even come with pre-attached underlayment, but you might need extra layers for sound or moisture proofing.

If you’re using a 2D floor planner to visualize your renovation, you’ll quickly see that skipping underlayment affects both the look and feel of your finished room.

Common Mistakes & Fixes

Here’s a story from my recent work: A homeowner installed laminate flooring directly on a concrete slab in Florida—a humid climate. Within months, the boards started buckling. We investigated and found moisture pooling beneath the boards. Fix? Install a proper vapor barrier plus a foam underlayment to prevent future damage. So always match your underlayment to your floor type and climate.

Another classic mistake is failing to clean and level the subfloor. Dirt, staple fragments, or uneven patches can create bumps and squeaks after installation. I recommend vacuuming thoroughly and patching dips before rolling out the underlayment.

Budget & Time Planning

Underlayment usually costs between $0.15 to $0.75 per square foot, depending on material and features. The installation itself is quick—roll out, cut to fit, avoid overlaps. But don’t rush: prepping the subfloor is essential to ensure no surprises down the road. A weekend DIY project becomes much smoother when you lay the right groundwork—literally.

Case Studies & Real Examples

A family in upstate New York tackled a full-floor renovation for their craftsman bungalow. Their subfloor was plywood, and they chose cork underlayment for thermal insulation and sound absorption. The result? Cozy rooms and zero complaints about foot traffic noise. From city condos to country homes, adding a layer like cork or foam transforms living spaces.

If you’re short on time, this table breaks it down:

Underlayment TypeBest ForKey FeaturesFoamGeneral living spacesAffordable, easy to install, basic sound dampeningCorkBedrooms, upper floorsSuperior sound absorption, warmthRubberBasements, high-moistureWaterproof, durable, expensiveVapor BarrierOver concrete slabsPrevents moisture migration, crucial for humid areas

Tips 1:

Always check the laminate manufacturer’s instructions—some brands void warranties if the wrong underlayment is used. Match your choice to your home’s needs: moisture-prone? Prioritize vapor barriers; looking for quiet? Try cork. For visualization and measurement, a free floor plan creator can help you plan your layers before shopping.

FAQ

1. Do I need underlayment for laminate flooring?
2. Yes, underlayment cushions, insulates, and protects your laminate from moisture. Some newer laminate comes with attached underlayment—always check manufacturer guidance.
3. What’s the best type of underlayment for concrete floors?
4. Use a vapor barrier plus foam or rubber underlayment to block moisture and create a comfortable walking surface. For more tips, see our guide to floor plan software visualization.
5. Can I reuse old underlayment when replacing laminate?
6. Unless it’s almost new with no signs of wear or moisture, it’s best to use fresh underlayment for each installation.
7. Is cork underlayment worth it?
8. Cork costs more, but it’s excellent for bedrooms or upper levels thanks to its sound absorption and insulating qualities.
9. Does laminate flooring work in basements?
10. Yes, but choose a waterproof underlayment or rubber—and always install a vapor barrier first.
11. How can I fix squeaky laminate floors?
12. Squeaks usually mean gaps or uneven subfloor. Remove boards, level the area, and reinstall with proper underlayment.
13. How thick should underlayment be?
14. Most types range from 2mm to 3mm. Too thick can affect the connection of boards—stick to manufacturer specs.
15. What tools do I need to install underlayment?
16. A utility knife, tape measure, and straight edge. Level the subfloor, lay the underlayment smoothly, and trim to fit.
17. Can I install laminate directly over tile?
18. Tile is generally okay if it’s stable, level, and clean. Use a foam underlayment for best results.
19. How long does underlayment installation take?
20. Most rooms can be prepped and covered in an hour or two—longer for larger spaces or complex cuts.
21. Should I glue underlayment to the subfloor?
22. No. Most underlayment is loose-laid. Only glue if specified by the manufacturer for specialty products.

Even small updates, like learning how to plan your layout for a seamless installation, make a big difference.

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