When you’re picking out new flooring, it’s easy to get caught up in the wood grain, the color, or the texture of the boards. But there is an invisible hero beneath your feet that determines how your floor feels, sounds, and lasts: the underlay.
At LKV Flooring, we explain the world of underlays to clients every single week. It can be confusing, but getting it right is the difference between a floor that feels solid and quiet, and one that feels bouncy or bothers the neighbors.
Here is everything you need to know about choosing the right underlay for your project.
1. The Price Spectrum: From Basic Foam to Professional Acoustic
Underlay pricing is usually calculated per square meter. The general rule of thumb? The thicker and denser the underlay, the higher the cost.
- The “Budget” Foam ($1–$3/sqm): You’ll find 1mm–2mm basic foam at big-box hardware stores. At LKV, we generally don’t use the 1mm version because it lacks professional quality. A slightly better 2mm foam with a moisture barrier is a starting point for basic residential floating floors.
- The “Quiet Step” ($5–$7/sqm): These are 3mm high-density underlays. They aren’t as soft as basic foam, which provides better support for your floor joints.
- Professional Acoustic Rubber/Cork ($15–$20/sqm): These are specifically designed for apartments and high-end homes. They are much denser and provide superior sound dampening.
- Top-of-the-Range “Dimple” Underlay ($30–$40+/sqm): These are 6mm thick with specialized “dimples” for maximum acoustic performance. They are heavy and more difficult to install, but they provide the best results for strict body corporate requirements.
2. Match the Underlay to Your Floor Type
Not every underlay works with every floor. Using the wrong one can actually damage your flooring over time.
Laminate Flooring
Laminate is almost always installed as a “floating floor.” It pairs well with more affordable foam or “Quiet Step” underlays. Because laminate boards are generally stable, these softer underlays provide a nice cushion.
Hybrid Flooring
Important: Most hybrid floors come with an underlay already attached to the back of the board.
- Houses: Usually, you don’t need any extra underlay.
- Apartments: You might need an additional layer to meet acoustic ratings. Crucially, you cannot use soft foam underlay for hybrid floors. Because hybrid has its own backing, adding another soft layer makes the floor too “bouncy,” which can break the clicking system. You must use a very dense rubber or cork underlay instead.
Timber Flooring
Timber gives you two main installation options:
- Floating: You can use 2mm or 3mm foam, but we recommend upgrading to a better acoustic underlay for first-floor rooms to reduce vibration.
- Glue-Down: This is what we specialize in at LKV. You cannot use foam for this. Instead, we use a “double-bond” method: the underlay is glued to the subfloor, and the timber is then glued to the underlay. This creates the most solid, high-quality feel.
3. The Apartment Challenge (Acoustic Ratings)
If you live in an apartment, your “Body Corporate” will likely have strict rules about noise. They usually require a specific acoustic rating to ensure you don’t disturb the neighbors below.
Professional acoustic underlays work “both ways”—they reduce the noise of your footsteps for you, and they stop the sound from traveling through the slab to the unit below. Always check your building’s paperwork before buying materials; we often have to match the underlay specifically to those requirements to avoid complaints.
Final Thoughts
Choosing an underlay isn’t just about price; it’s about the technical requirements of your subfloor and your building.
- Laminate? Go for a 2-3mm foam or quiet step.
- Hybrid? Stick with the attached backing or use a dense rubber/cork if needed.
- Apartment? Check your acoustic ratings first!
Still confused? Come visit us in the showroom! We’re happy to show you these samples in person and help you find the perfect match for your home.
