Best Carpet Underlay – Expert Guide

Carpets are considered to be one of the most comfortable floors on the market. For many homeowners, that’s usually enough. They don’t think, or maybe don’t even realise, how a simple underlayment can radically transform the look, feel and properties of a carpet. Underlayments provide a range of benefits, including enhanced comfort, warming insulation, noise reduction and cushioning.

But with so many high-quality carpet underlayments, each with its strengths, who is to say which is the best one? QA Flooring has made this guide to ensure that our customers make an informed decision on the wide range of underlayments available. The areas we will cover are as follows: 

    • What Carpet Underlays Are

    • Types of Carpet Underlays

    • Key Factors to Consider When Choosing a Carpet Underlay

    • Best Carpet Underlays for Different Needs

    • Carpet and Underlay Compatibility Issues

We plan to cover every aspect possible in this guide. That being said, we have a Traffilay system, which is a simple, easy-to-follow interactive guide to narrow down the best options for you. 

So without further ado, let's get started. 

What are Carpet Underlays? 

A carpet underlay is a layer of material installed between a carpet floor and the subfloor, to enhance the experience of the carpet itself. The materials they are made from differ between underlayments, but they are usually made of PU foam, rubber and felt, or some combination of the three. 

Types of Carpet Underlays 

Carpet underlays come with different materials, and you are looking to take advantage of the different properties the materials bring to complement your floor. 

    • Polyurethane (PU) Foam Underlay is the most popular and cost-effective choice due to its comfort, insulation, and compression recovery capabilities. Its versatility allows it to complement carpets of many different types, materials and uses - such as from general domestic to luxury. It is lightweight, meaning it’s easy to move and install. PU Foam Underlays differ in terms of thicknesses and densities, allowing you to tailor the level of cushioning to what you need or prefer. 

    • Rubber Underlay - Rubber is a material known for its density and durability. The support that they give to the carpet comes in the form of being able to resist the wear and tear that often comes with high-traffic areas. On top of this, they provide excellent sound cushioning, meaning that they absorb a lot of the sound that would come from movement across the floor. 

    • Felt Underlay - Felt underlays are made from fibres that have been recycled, meaning they are a nice eco-option. 

    • Combination Underlay - Combination underlays are, as the name implies, made up of different types of materials to create a hybrid that has the benefits of all. This of course makes them ideal for use with specific carpet types such as Axminster - ensuring that you get a nice level of comfort and durability at a price that reflects the value you have invested in your carpet.

What is QA Flooring’s best underlay per need?

The following section will answer which of the following underlays are best from our range of top-tier products. 

Best Carpet Underlay for Underfloor Heating

The best carpet underlay for underfloor heating is the Heatwave. This boasts the highest TOG rating which is a low 1.2. It even has the added benefit of being flame retardant. As a bonus, this underlay has an 8mm thickness, making it very comfortable underfoot. 

Best Carpet Underlay for the Environment

Breathe is a completely natural alternative to PU foam underlays and is made from wood fibre. It has a unique ability to improve the air quality in your home and is completely recyclable at the end of its life.  Another contender to consider would be CombiFelt Acoustic, made from recycled rubber and felt.

Best Carpet Underlay for Comfort 

QA’s Pure range is unsurpassed in terms of comfort with Pure UHD 11mm and Pure SHD 11mm being very high-density underlays suitable for luxury domestic use in heavy traffic areas. The Pure range uses the purest, highest-grade PU foam for superior cushioning and compression recovery.

Best Carpet Underlay for Durability 

When it comes to durability, two of the range of underlays from QA stand out. Pure UHD 9mm is an ultra high-density underlay ideal for compression recovery, and heart insulation and is suitably hard-wearing enough for luxury domestic use in heavy traffic areas.  PowerWalk Silver, again excels in being hard-wearing due to its 130kg density and compression recovery. Both perform under pressure and are ideal for reducing wear and tear on your carpet.

Best Carpet Underlay for Insulation 

Are you trying to improve the energy efficiency of your home, and save money whilst you do? One of the best underlays in our arsenal that combats heat transfer is Pure SHD 11 with a Tog rating of 3.04. This is amongst the highest levels of insulation seen amongst underlays.  A choice would be PowerWalk Gold. This highly comfortable and hard-wearing underlay has a 2.92 Tog.

Best Carpet Underlay for Noise Reduction

Our Pure SHD 11mm is rated with a very impressive 44dB for impact sound reduction, as well as being hard wearing and delivering on cushioning, and compression recovery.  PowerWalk Gold is another strong contender, again with a 44dB rating but with a slightly lower insulation value.

Underlay and Carpet Compatibility 

As we mentioned briefly before, some underlays are not compatible with certain carpets. In this section, we will detail what these types of carpets are, and what does and doesn’t work with them. 

    • Loop Pile Carpets - Also known as Berber carpets, these are made with a yarn that forms loops on the surface. The result is a durable and resistant carpet with high durability for areas of high traffic. The underlays you want for these are typically medium-firm ones, as they can provide good support for the unique looping structure and avoid stretching the carpet. However, using soft or thick underlays could lead to over-compression, and damage the carpet as a result. 

    • Twist Carpets - These carpets are known for, and named after, the twisting fibres that are set deep within the backing. The textured surface resists wear and tear, making it a fairly durable carpet. It’s a comfortable enough carpet as standard but can be made even more so with a soft underlay. But ensure it’s not too dense and hard. This could reduce the plushness of the carpet and make it overly hard. 

    • Velvet Pile Carpets - These carpets have a short, dense pile that gives a smooth luxurious feeling. Soft plush underlays can further enhance the feel without causing any damage. These carpets are very warm, so underlays that provide insulation will further enhance the comfort and heat retention within your room.

    • Saxony Carpets - These carpets are dense, and have long plush fibres. An underlay with good cushioning is recommended for these, as they can enhance the comfort by complimenting its softness, whilst you should steer clear of harder underlays that would detract from it. 

    • Woven Carpets - These carpets are woven through a loom, and are therefore quite hard and durable. They are, however, high quality, and pair well with firm underlays that can support their weight. Softer underlays may make the carpet feel softer but provide inadequate support. 

    • Natural Fibre Carpets - These carpets are made from natural materials and can have a rough texture. Again, a firm underlay is recommended for this, as it can match the toughness of the carpet. 

Best Carpet Underlay Conclusion

We hope this guide has been helpful, and that you can move forward with the information you need to make an informed decision. If you still have issues deciding, feel free to consult with QA’s expert flooring installers or use the aforementioned Traffilay system. 

Best Carpet Underlay - Expert Guide - FAQs

  • Why should I get an Underlay?

    Underlayments give a bunch of benefits to the floor above it. Here are some of these benefits. 


    Carpets are already some of the most comfortable flooring options on the market, but an underlayment can add another dimension to this facet. With an underlayment, you can expect a sharp rise in the definition of the softness and springiness of your steps. This is done through shock absorption and compression recovery, meaning the underlayment’s materials can take and spread out the weight of your steps across its material and easily bounce back into shape. By taking the pressure off the carpet itself, the fabric will feel a lot more soft and comfortable. 


    Since the underlayment absorbs the shock, it also absorbs the wear and tear that would otherwise be inflicted on your carpet. As a result, your carpet will remain in pristine condition for much longer, as well as increasing its life span. You will not only save money but enjoy a fresher-looking carpet. 


    This is one of the more impressive elements of underlayments. An underlayment’s insulation benefits not only make your home more comfortable in terms of temperature but also prevent the escape of heat through your floor. This means that not only will your home remain at consistent warmth, but you will spend less on heating due to not losing the heat you generate. The great thing about this is that, over time, your underlayment could well end up paying for itself in saved costs. 

    Noise Reduction

    Whilst carpets are not necessarily a noisy flooring option, the subfloor beneath it can still make noise against your walk. The noise can be absorbed with an underlayment, leading to a much more peaceful house. This can be particularly useful on the second floor of your home, ensuring that you’re not disturbed by noise transmission between rooms or floors. With this, underlayments contribute to a more peaceful, comfortable home. 

  • How do I choose the right underlay for me? 

    The right underlay for you is almost certainly the underlay offering the benefits that you prioritise the most. Things such as:

    • Thickness - Your Underlay’s thickness will generally determine how comforting your underlay is. Underlays typically range between 6mm to 12mm in terms of thickness, with the thicker side providing a greater level of comfort and cushioning. That being said, understand that they may not be compatible with all types of carpets. It’s possible that adding an underlay to an already thick carpet, such as those with a low pile or dense weave, could make a carpet feel too soft, to the point of feeling unstable. 
    • Density - Density is different from thickness. Density refers to exactly how much material, on a kg per cubic metre basis, is packed into the space in question. So, underlay A can be thicker than underlay B, but underlay B can be stronger, due to density. Meaning, of course, that high-density underlays provide better support, and can determine how long underlays will last. 
    • Tog Rating - A Tog Rating measures the thermal resistance of an underlay, which of course is the process of being able to retain heat and stop it from escaping. High insulation underlays can contribute to reducing energy bills. That being said, if you are interested in underfloor heating, a high Tog rating will actively work against you. So a low Tog rating is recommended for use with underfloor heating.
    • Sound Reduction - Sound reduction can be provided by the type or density of the material used. The higher the dB rating the better the insulation for impact sound reduction

Take a look at our extensive range of underlays & accessories

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Take a look at our extensive range of underlays & accessories