When putting in new flooring, most people only think about the surface — whether it’s laminate, vinyl, wood, or carpet. But what’s underneath is just as important: the underlay. Flooring underlay is a thin layer of material that’s fitted between the subfloor and your floor covering of choice. It may not be seen, but it’s responsible for comfort, durability, insulation, and even soundproofing.
Whether you’re installing flooring for your living room, kitchen, or hallway, knowing the importance of underlay can end up saving you money, avoiding future problems, and improving the performance of your flooring. So, do you actually need it? Let’s find out.
What Is Flooring Underlay, Exactly?
Flooring underlayment is a shock-absorbing material composed of foam, rubber, felt, cork, or other man-made materials. It’s usually sold in rolls or sheets and has different thicknesses and densities based on the type of flooring and condition of the subfloor.
Underlay performs a variety of purposes. It smoothes out small defects in the subfloor, acts as a moisture barrier (particularly over concrete), enhances insulation, helps dampen impact noise, and creates comfort when walked upon. For certain flooring such as laminate or engineered wood, it’s virtually always required.
Various Types of Underlay Explained
Every type of flooring has an appropriate underlay that corresponds with its material characteristics and with the particular demands of the space. Here is a division of basic forms of underlay:
| Underlay Type | Best For | Features |
|---|---|---|
| Foam Underlay | Laminate Flooring | Lightweight, budget-friendly, basic insulation |
| Rubber Underlay | Vinyl or High-Traffic Areas | Durable, moisture-resistant, acoustic support |
| Felt Underlay | Carpets | Excellent comfort, warmth, and durability |
| Cork Underlay | Eco-conscious Flooring | Natural insulation, hypoallergenic, mould resistant |
Why You Need Underlay for Laminate Flooring
Laminate flooring is a floating floor system, i.e., it is not glued or nailed down to the subfloor. Due to this, an underlay is necessary to maintain the laminate stable and operational. It serves to cushion the hard surface, absorb footfall sound, and guard against moisture — particularly in areas such as kitchens or utility rooms.
Additionally, underlay can greatly increase the life of laminate flooring by stopping the boards from coming into direct contact with the subfloor, which may lead to wear or movement over time.
Underlay for Vinyl Flooring: Is It Always Necessary?
Vinyl flooring has gone a long way – from sheets to luxury vinyl planks (LVP) and tiles (LVT). Some of the modern vinyl floors come with a built-in underlay, specifically in click-lock installations. Yet, if yours doesn’t have it, you might have to put one in on its own for extra cushioning, soundproofing, and water protection.
The decision to employ vinyl underlay also relies on your subfloor. Concrete subfloors appreciate underlays that contain built-in damp-proof membranes (DPM), whereas wooden subfloors may only require minimal cushioning to avoid squeaks and increase comfort.
Carpet Underlay: Not Optional
For carpets, underlay is not an extravagance — it’s a requirement. Quality carpet underlay adds extra comfort to walk on, improves thermal insulation, lessens noise, and prolongs the life of the carpet by soaking up the shock of footfall.
Forgetting carpet underlay will wear out the carpet prematurely, make it less comfortable, and prevent it from insulating the room. In colder UK homes, the thermal gain alone makes it worthwhile.
When You Might Get Away With Omitting Underlay
Underlay is greatly recommended for many types of flooring, but in a couple of situations, you might be able to skip it. A couple of products have preattached underlay for some vinyl and laminate flooring. If your subfloor is ideally flat, dry, and even, and your floor has a built-in layer of underlay, you can avoid adding extra.
However, even in those cases, double-checking the manufacturer’s installation guide is essential — as over-insulating or improper layering can void warranties or cause flooring to fail.
Subfloor Considerations Before Choosing Underlay
Before installing any underlay, it’s important to evaluate your existing subfloor. Is it concrete, plywood, chipboard, or existing tiles? Does it slope, dip, or have any moisture issues?
For concrete, an underlay that is resistant to moisture with a DPM is essential to avoid water vapour from harming the flooring above. For wooden subfloors, a flexible and breathable underlay is best to allow for natural movement. Always fix cracks or gaps in your subfloor prior to laying anything on top of it.
Acoustic and Thermal Benefits
Perhaps the most underrated advantage of underlay is sound reduction. In flat, hallway, or upstairs room settings, soundproofing is a significant consideration. Acoustic underlays work to dampen footfall noise, soften echoes, and make the home a more serene space.
From a thermal insulation perspective, good quality underlays minimize heat loss, especially on ground floors. Not only does this enhance comfort, but it can also lead to reduced energy bills — and that makes it a good long-term investment.
DIY vs Professional Underlay Installation
Installing underlay can be a DIY project if you’re comfortable with measuring, cutting, and securing materials accurately. However, getting it wrong — by overlapping or misaligning — can lead to problems with your finished flooring.
For optimum performance, particularly in high-traffic or high-value rooms, it’s advisable to engage professional fitters who have the knack of the correct combination of underlay, subfloor, and flooring type. At Q Flooring, our professionals take every effort to ensure each layer is positioned exactly, maximizing the lifespan and quality of your floor.
Final Thoughts: Is Flooring Underlay Worth It?
Yes. Flooring underlay is not an unnecessary step — it’s a fundamental component of any successful flooring project. Whether to provide comfort, moisture protection, noise reduction, or durability, the proper underlay guarantees your new floors get the best from themselves and also last longer.
So, tempting as it might be to avoid it for the sake of the budget, underlay is actually a budget-friendly upgrade that justifies itself in several ways.
