Do You Need Underlayment for Laminate Flooring? Pros, Cons & Real Advice: A Designer’s Guide to Whether You Should Install Underlayment Under Laminate Flooring—Plus Mistakes to Avoid

One of the most common questions for homeowners and DIYers tackling a new flooring project is: do you have to put underlayment under laminate flooring? It might sound like a small detail, but this decision can make or break your floor’s comfort, durability, and even warranty coverage.

From my own experience as a designer working with hundreds of American homes—spanning old Victorians in Boston to contemporary condos in Chicago—the choice of underlayment is rarely an afterthought for a seasoned pro. Let’s break down why.

Choose the Right Tools

Before you even start with underlayment discussions, make sure you have a reliable 2D floor planner or similar tool to accurately measure and map your rooms. This helps you estimate material needs and spot potential problem areas, like slopes or moisture-prone zones.

What Does Underlayment Actually Do?

Underlayment is a thin pad—usually foam, felt, or cork—that sits between your subfloor (plywood, concrete, etc.) and the laminate planks. Here are its main jobs:

1. Moisture Barrier: Prevents moisture from below ruining your laminate.
2. Sound Reduction: Minimizes “click-clack” footsteps on laminate floors (especially in apartments).
3. Smooths Minor Imperfections: Helps create an even surface if your subfloor is slightly uneven.
4. Adds Comfort: Provides a little cushion underfoot for a softer, warmer feel.

Level of Detail & Time

Most laminate manufacturers recommend (or even require) underlayment, especially for floating installations. Skipping it might void your warranty. On average, underlayment adds an extra day to your install—less if you’re handy or working with modular, click-together pads. But this step can prevent major headaches down the road.

Case Studies & Real Examples

I once worked with a family near Portland who wanted to cut costs and skipped the underlayment, installing laminate directly over a lightly uneven plywood subfloor. Within a few months, they noticed creaking sounds, uncomfortable cold spots, and—worse—a musty odor after a rainstorm due to subfloor moisture.

Contrast this with a recent open-plan living room project in New Jersey: we used a moisture-barrier underlayment over concrete, and not only did it solve the echo issue, but the space felt warmer and quieter. The homeowners raved that it felt more like solid hardwood than laminate.

Common Mistakes & Fixes

1. Forgetting vapor barrier over concrete: Always use a vapor barrier layer if the subfloor is concrete or for ground-level installations.
2. Stacking incompatible layers: Some laminates have attached underlayment—don’t double up unless the manufacturer specifically allows it.
3. Neglecting to tape seams: Always tape underlayment seams to prevent shifting and gaps.

Budget & Time Planning

Expect to budget $0.25–$0.75 per square foot for underlayment—an extra $50–$200 for most rooms. Installation typically doesn’t require special skills, making it a common DIY step if you’re using an online DIY room decor planner to visualize layers and materials costs.

FAQ

1. Do all laminate floors require underlayment?
2. Most floating laminate floors do, especially for sound and moisture protection. However, some products have underlayment pre-attached—check your box and the manufacturer’s instructions.
3. Can I skip underlayment if my subfloor is in perfect condition?
4. Even with a flawless subfloor, you risk a harsher sound, colder flooring, and possible moisture issues. It’s rarely worth skipping unless your product explicitly forbids it.
5. Is underlayment needed over old vinyl or tile?
6. In most cases, yes. Underlayment smooths imperfections and acts as a buffer, but check the laminate’s requirements for details.
7. How thick should my underlayment be?
8. Most quality underlayments are 2-3mm thick. Thicker options exist for extra soundproofing, but check if your laminate allows thicker pads.
9. What happens if I double up with two underlayment layers?
10. This usually creates too much flex, causing seams to break. One suitable layer is the norm unless your flooring specs say otherwise.
11. Can I use carpet padding as underlayment?
12. No, carpet padding is too thick and soft, causing laminate joints to fail.
13. Does underlayment add warmth?
14. Yes—a good underlayment makes laminate more comfortable and less chilly, especially in winter climates.
15. Will skipping underlayment void my warranty?
16. Most manufacturers require underlayment for their warranty to be valid—always check their policy.
17. How do I handle transitions between rooms?
18. Use transition strips and run underlayment to the strip. Don’t overlap different underlayments across rooms.
19. Do I need underlayment for a radiant heat system?
20. Use underlayments designed for radiant heat—standard types may trap too much heat and damage your lamiante.
21. How do I choose the right underlayment?
22. Consider your subfloor (wood vs. concrete), sound goals, and local climate. Many pros rely on a home designer workflow to compare product specs before purchasing.
23. Can I install laminate directly over old wood floors?
24. Yes, but underlayment is still recommended for noise and leveling—even if the wood is flat.