Do I Need Underlayment for Laminate Flooring on Plywood?: Expert Advice on Installing Laminate Over Plywood: Is Underlayment Necessary?

Let’s get one thing straight: laminate flooring can seriously upgrade the look of any room, but the trick to making it look and feel like the real deal is all in the prep—specifically, the underlayment. If you’re putting laminate over a plywood subfloor, you’re probably wondering: do you need underlayment, or can you skip it?

As a designer who’s tackled floors in everything from Boston brownstones to sunny California bungalows, I want to break down the facts as well as some real-life experience.

Short answer: Nearly always, yes—you do need underlayment beneath laminate flooring even if your subfloor is plywood. Let’s talk about the why, how, and what to consider in your own project.

Project Planning: Why Underlayment Matters

Underlayment isn’t just a manufacturer’s suggestion—it’s a crucial layer for three core reasons:

1. Moisture Barrier: Protects your floor from minor moisture that can creep up from below (yes, even plywood can transfer vapor, especially in older homes or above crawl spaces).
2. Cushioning: Levels out minor subfloor imperfections, reducing the risk of noise and even cracking over time.
3. Acoustic Control: Dampens footsteps, so your floors don’t sound hollow or clicky—makes a huge difference, especially in bedrooms or upper floors.

From my own projects, skipping underlayment always leads to regrets—usually in the form of echoing footfalls and chilly toes. The added comfort and noise reduction are worth every penny.

Level of Detail: Choosing the Right Underlayment

Not all underlayment is created equal. Here’s what you need to consider:

1. If your laminate already comes with attached underlayment, you usually don’t need (or want) an extra layer—double layers can actually cause shifting.
2. For most DIY jobs on plywood, a standard foam underlayment is perfect. If you need extra moisture protection (like above a crawl space), look for a product with a built-in vapor barrier.

Want the essentials? Check this cheat sheet.

Scenario Underlayment Needed? Notes Laying laminate over basic plywood (dry area) Yes Foam underlayment works Plywood over humid/crawlspace areas Yes Moisture barrier underlayment Laminates with built-in pad Usually no Double layer not recommended Common Mistakes & Fixes

I’ve walked into more than one DIY rescue where the homeowner thought “plywood is smooth enough—why bother with an extra layer?” Trust me, after a New York project where tiny subfloor gaps led to loud creaks within a month, I always advise:

1. Don’t assume plywood means you can skip underlayment.
2. Avoid double-layering if your laminate already has an integrated pad.
3. Use transition strips between rooms with different flooring thicknesses.

There’s also an unexpected bonus: underlayment helps with room planning for future projects—you can change out laminate with minimal fuss, without damaging the subfloor.

Budget & Time Planning

Underlayment is one of the most cost-effective upgrades you can make in your floor project. According to Statista’s 2025 homeowner survey, about 65% of laminate installs in the US use underlayment to boost performance and lifespan.

The good news: installing underlayment is quick and extremely DIY-friendly. It rolls out easily and doesn’t usually require adhesives or nails when going over plywood. For a 250 sq. ft. room, you’ll spend about $40–$80, and an hour to install. That’s a small investment for major comfort and results.

If you’re mapping out the entire installation, using a Floor Plan Creator first can help you estimate your underlayment needs precisely.

Case Study: West Coast DIY Success

A client in Portland reached out after feeling frustrated with cold, noisy laminate in her bedrooms (directly over plywood). We installed a cork-backed underlayment and the difference was immediate—no more echo, and the rooms felt warmer. Plus, her energy bills dropped a bit, likely from improved insulation. She later became a full-blown AI design enthusiast, planning every room virtually ahead of upgrades!

FAQ

1. 1. Can I install laminate flooring directly on plywood without underlayment?
2. Technically, you can, but you’ll lose sound dampening, comfort, and risk potential moisture issues. Most manufacturers require underlayment for warranty.
3. 2. Is a vapor barrier necessary over plywood?
4. If your subfloor is above a conditioned, dry area (like an upstairs bedroom), a regular foam underlayment without a vapor barrier is fine. For ground-level rooms or those over crawlspaces, use underlayment with a moisture barrier.
5. 3. Will underlayment make my floors quieter?
6. Absolutely—it significantly reduces hollow or clicking sounds, especially important for multi-story homes.
7. 4. What’s the best underlayment for plywood subfloors?
8. For most dry, interior areas, basic 2–3mm foam underlayment is ideal. For added insulation and soundproofing, cork is an excellent (though pricier) upgrade.
9. 5. Can underlayment help with uneven plywood?
10. Underlayment can mask subtle imperfections, but for major dips or warps, you’ll need to patch or sand the subfloor before installing laminate.
11. 6. Is it ever okay to double up on underlayment?
12. No—it can cause laminate to shift too much underfoot, shortening its life.
13. 7. Does underlayment add insulation?
14. Yes! You’ll notice warmer floors in winter, especially with cork or specialty insulative pads.
15. 8. How can I estimate how much underlayment to buy?
16. Measure the square footage of your installation area. Online tools like a 2D floor planner can help you get exact measurements, including closets or odd angles.
17. 9. Does adding underlayment slow down installation?
18. Not at all—in fact, it can make laminate installation easier overall by smoothing over minor gaps or staple heads in plywood.
19. 10. What happens if I skip underlayment?
20. You’ll likely hear more noise, feel colder floors, and potentially void your flooring warranty. Plus, you may see more visible wear over time.
21. 11. Are there eco-friendly underlayment options?
22. Yes, underlayment made from recycled felt, cork, or natural fibers is available and ideal if you’re focused on sustainability.
23. 12. Can I use leftover carpet padding as underlayment?
24. No, carpet padding is too thick and soft, which can cause laminate joints to break.