Why Underlayment Is Not Optional
Many homeowners see underlayment as an unnecessary extra cost. It's not. Laminate flooring installed without proper underlayment feels hollow and cheap underfoot, transmits every footstep sound to the floor below, and wears out faster because there's nothing cushioning the locking joints from subfloor imperfections. Quality underlayment makes the difference between laminate that sounds like a real floor and laminate that sounds like you're walking on a drum.
Key Specs to Compare
IIC Rating (Impact Insulation Class)
Measures how well underlayment reduces impact sound (footsteps, dropped objects). Higher is better. Standard underlayment scores around 50–60 IIC; premium acoustic underlayment reaches 65–73 IIC. Critical if you have rooms below your installation.
STC Rating (Sound Transmission Class)
Measures how well underlayment reduces airborne sound (voices, TV). For multi-story homes or apartments, look for STC 60+.
Thickness
2mm–3mm is standard. Over 3mm can interfere with door clearances and transition strips. Some flooring manufacturers specify maximum underlayment thickness — check your flooring warranty.
Vapor Barrier
Essential for any installation over concrete (basement, slab-on-grade). A built-in vapor barrier prevents moisture from migrating up through the concrete and damaging the laminate. If your underlayment doesn't have one and you're going over concrete, add a separate 6-mil poly vapor barrier.
1. Roberts 70-193A — Best Overall
The Roberts 70-193A is the most popular laminate underlayment on Amazon for good reason. The 3-in-1 design combines underlayment, moisture barrier, and sound reduction in a single product. The built-in tape along one edge makes installation clean and prevents overlap gaps. Works over both wood and concrete subfloors. Covers 200 sq ft per roll.
2. FloorMuffler UltraSeal — Best for Noise Reduction
If noise between floors is your primary concern, FloorMuffler UltraSeal is in a different class than standard underlayment. The dense foam construction achieves an IIC of 67 and STC of 66 — significantly better than most competitors. The self-sealing overlap tape eliminates moisture gaps. Worth the premium price for above-garage rooms, second floors, or any space where footstep noise is an issue.
3. QuietWalk QW100 — Best for Radiant Heat
If your home has radiant floor heating, standard foam underlayment insulates against heat transfer and reduces efficiency. The QuietWalk QW100 is specifically designed for radiant heat systems — it allows heat to pass through while still providing acoustic benefits.
Quick Installation Tips
- Lay underlayment perpendicular to the direction of your flooring planks
- Overlap seams by 2–3 inches and tape with the included tape or foil tape
- Run underlayment 1–2 inches up the wall — trim after flooring is installed
- Do not double up underlayment to add more cushion — too much flex weakens the locking joints