Whether you’ve just bought a new floor, or you’re replacing your existing one, it’s important to choose the right underlay to go with it. An effective underlay will provide thermal insulation, increase the comfort of your floor and reduce the amount of noise from footfall.

We’ve compiled a few commonly asked questions to help you decide what kind of underlay to use for laminate or wood flooring.

What thickness and spec underlay should you use?

Know your TOG

The quality of underlay can be measured by the TOG rating which is used to monitor thermal insulation and how effective it is. The higher the TOG rating, the better the level of insulation.

What’s a DPM?

If you have a concrete subfloor, then you definitely need a DPM. A damp proof membrane (DPM) is usually placed underneath a concrete subfloor to stop moisture from travelling through the floor. New-builds and homes built after the 1970s should have a DPM already fitted beneath the concrete.

Thickness

You might think it’s okay to choose thick underlay for better comfort but unfortunately, that’s not necessarily always the case. There are a number of different factors to consider when choosing the thickness of your underlay.

If you’re fitting underfloor heating, this will impact the thickness of your underlay. If the underlay is too thick, the heat will find it hard to travel through the boards.

The thickness of your underlay could also affect the joining mechanism of your floor. For example, when choosing what kind of underlay to use for laminate flooring, a foam underlay that’s thicker than 5mm won’t be ideal, as it may cause the click-fit system to un-click.

What material underlay should you use?

Foam Underlay

✔ Ideal for solid wood, engineered wood and laminate

If you’re looking for an affordable underlay to fit under a wood or laminate floor, foam underlay is the way to go. It’s comfortable to walk on, provides cushioning underfoot, absorbs sound and does a great job of keeping your room warm.   

This kind of underlay is also underfloor heating compatible, so you can enjoy toasty toes all year round! 

⚠ Remember to use a DPM when you install your foam underlay, as otherwise your flooring may be damaged by damp.  

⚠ Make sure your subfloor is completely level to prevent problems with the joints of your flooring. 

Foam and Foil underlay

Ideal for laminate and wood flooring (provided the underlay thickness is suitable)

Our 7mm Foam and Foil Underlay for laminate and wood flooring

Foam and Foil underlay offers all the advantages of foam underlay but has the additional benefit of foil backing, which reduces heat loss and in turn, helps keep your energy bills down! 

This type of underlay also boasts a built-in damp proof membrane (DPM), protecting your floor from damp-related damage.  

⚠ As with standard foam underlay, it’s important to consider the thickness and TOG rating of your underlay if you’re installing underfloor heating. 

⚠ As previously mentioned, foam underlay that’s more than 5mm thick could affect the joining mechanism of your floor, making it unstable or causing gaps between the planks. 

Thermal underlay

Ideal for laminate, vinyl and engineered wood flooring

Thermal underlay with floor planks on top
Our 1.8mm Thermo-X Underlay can be used with any of our flooring products

Thermal underlay is the choice for you if you’re installing underfloor heating. It’s also great if you’re just looking to keep your home that little bit more toasty! Not only does it keep your floor warmer for longer, but the thermal barrier stops moisture from damaging your floor, keeping your home damp-free!

⚠ Just to remind you - if you’re wanting to install underlay on top of underfloor heating, then you need an underlay with a fairly low TOG rating. This will allow as much heat as possible to pass through the underlay and warm up the room.

Fibreboard underlay

✔ Ideal for engineered wood and laminate flooring

Person laying fibreboard
Our 5.5mm Fibreboard Underlay for engineered and laminate flooring

If you’re wondering what’s the best underlay for laminate or wood flooring, Fibreboard is a brilliant choice. It helps smooth uneven floors, reduces noise and acts as an excellent thermal insulator. Not to mention, it's also the number one choice of underlay for laminate and wooden floors.

If you have an uneven subfloor, the fibreboard will help even any dips and dents you can't level out.

⚠ Remember to add a DPM if you're fitting fibreboard on top of a concrete subfloor, as moisture may cause your floor to warp. Fibreboard can be laid loosely but we recommend you use joint tape to attach the boards together. 

⚠ Remember, wood and water don’t mix! Fibreboard shouldn’t be used in rooms that get wet, like bathrooms and wet rooms.

Cork underlay

✔ Ideal for tile and stone. Cork underlay comes pre-attached with some luxury vinyl tiles

lamnate flooring with cork underlay
Cork underlay comes pre-attached on some LVT products

If dampening sound is a priority in your home, then cork underlay might be the answer to your problems. Cork underlay is one of the most hygienic choices on the market, as it prevents the growth of mould, bacteria and mildew. It's also super eco-friendly and works as an excellent insulator. 

⚠ However, cork is not waterproof. We would not recommend laying cork underlay with laminate flooring in rooms that are prone to getting wet. 

The best way to install cork underlay is to glue it directly to the subfloor. Cork is suitable for hardwood floors such as solid and engineered wood. You can also fit cork underneath carpet, linoleum, stone and tile flooring. The possibilities are endless!

Which underlay is best for my home?

 Use for Sound reduction Thickness Tog UFH compatible Includes Damp Proof Membrane (DPM)  
Foam Wood & Laminate 12db 2mm 0.4 Yes No 
Thermal Foam Any floor 21db 1.8mm 0.2 Yes No 
Fibre Wood & Laminate 21db 5.5mm 0.5 No No 
Cork LVT 24db 1mm 0.4 Yes No 
Foam & Foil Wood & Laminate 19-23db 3-5mm 0.5-0.9 Yes Yes 
IXPE LVT 15-18db 1mm 0.5 Yes No 

How to prep your subfloor for underlay

Man pouring self levelling compound on subfloor
  1. Start by removing any nails, staples or other objects protruding from the subfloor. Then clean the subfloor thoroughly to ensure it’s free from grease, paint, oil or other substances that could affect the process of laying your underlay.
  2. Ensure your subfloor is completely level. You don’t want your newly laid floor to have any unsightly dents!

    Use a long level to check your subfloor. It must be level within 0.47 cm for every 3 metres. If your subfloor needs to be levelled, a cement compound or an epoxy-based self leveller can be used.
  3. Ensure the self-leveller has completely set (follow the timings recommended on the instructions) before moving on to the next step.
  4. Measure the thickness of the subfloor. The thicker your subfloor, the more stable it’ll be. We recommend it’s at least 2 cm thick for the best results.

Tips on laying underlay

  • If you’re installing your floor over concrete, you must have an underlay that includes a damp proof membrane (DPM). This blocks out any moisture that may cause damage to your floor.
  • You don’t need to buy extra underlay for luxury vinyl tiles as the majority of them come with pre-attached underlay, often made from cork or foam.
  • If you’re nailing down your floor, you can nail through the underlay.
  • Like your floor, you should fit the underlay lengthways across the room.

And there you have it. Once you’ve decided what underlay to use for your laminate or wood flooring, explore our collection of underlay options to find the best one for the job!


Still unsure what underlay to choose for your laminate or wood flooring? Our team of friendly flooring experts are here to help, so get in touch today!

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