In our opinion it is false economy to fit new carpet over old underlay. Carpets need to have as firm a support as possible in order to achieve its maximum performance. An old underlay will already have become flattened and less resilient to a greater or lesser extent depending on its use and will not give the carpet adequate support.
Choose from our entry level UK made Super 10mm Underlay to the super luxury of Plushwalk 12mm Underlay which is the best underlay on the market.. We offer a huge choice of over 50 underlays to cover every budget and application.
We stock some exceptional carpet underlays for those on a budget with our entry level Super 8mm Underlay or Super 10mm Carpet Underlay PU foams which are made here in the UK. Also wool felt carpet underlays offer fantastic value and are kind to the environment being made from 100% recycled materials. For laminate and wood flooring installations our cheapest is Royale 2mm White Underlay foam from an incredible £0.29 per sq mtr. However, our best value will be the Royale 3mm Acoustic Silver.
For Wood or Laminate For Carpets
Royale Comfort White 
Super 8mm Carpet Underlay
Sound Insulation
The installation of underlay reduces sound not only in the room itself but also the transference of sound to the room below. Our top-rated Sound Insulation Underlays is the Plushwalk 12mm, with a massive 48dB approx. this is one of the top-rated underlays for sound insulation as well as Carpenter Deep Step with a 46Db rating.
https://www.carpet-underlay-shop.co.uk/collections/underlay-acoustics
Heat Insulation
By using carpet underlay you are providing an additional layer of insulation, which reduces the heat loss through floorboards and reduces under floor draughts.
Our best performing underlays with high TOG ratings is the luxury wool 56oz underlay with an impressive 3.6TOG approx.
Because its made from wool, wool is a fantastic heat insulator - just like you have wool scarves, wool duvets and so forth...
https://www.carpet-underlay-shop.co.uk/collections/thermal-insulation-underlay
Dust Insulation
The underlay acts as a barrier by reducing the flow of air, thereby reducing the dust particles carried by the air.
Wool 42oz provides excellent comfort and durability along with excellent heat and sound insulation properties. It allows air circulation and carpets to breathe and so reduces dust within in the room.
Comfort
Carpet underlay produces an extra softness to the feel of the floor, regardless of the quality and thickness of the carpet.
The best comfort underlay, again belongs to Plushwalk 12mm, this is a super luxury underlay made using memory foam properties which gives outstanding levels of cushion/softness underfoot.
We also recommend Super Velvet underlay as the 2nd best for comfort and also great at acoustic reduction
Appearance
The carpet underlay absorbs all the wear and tear keeping your carpet looking better for longer.
Carpet Fitting
The majority of domestic carpets are fitted using a method whereby the carpet is stretched onto carpet grippers. The use of underlay is therefore practical as it raises the level of the floor in line with the gripper pins, which enhances the finished look of the fitted carpet. If you are looking for a Carpet-Underlay-Shop approved fitter then please CLICK here.
Minimises furniture indentations
Underlay supports a carpet and therefore helps to prevent furniture from spoiling the look of your carpet.
Carpets are installed on a wide variety of underlays and whilst we know that in the majority of cases an acceptable performance of carpet and underlay may be achieved, careful choice of underlay can actually enhance the performance of the carpet. We acknowledge that there is a balance to be achieved between providing the right underfoot comfort and the right support to the carpet.
These do not have a cushioned backing and therefore underlay is essential.
Secondary backed Carpets
These are the most common carpets used in the domestic market. The backing is either a polypropylene mesh or hessian and therefore has no cushioning. Underlay is therefore essential.
Felt backed carpets
These carpets have a thin felt back and are often sold described as having in built in underlay. However they offer little in the way of the benefits listed above and we would recommend therefore that they be placed in top of an underlay with a smooth surface.
Foam Backed Carpets
Underlays are not recommended for use with these types of carpets.
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Benefits of Firmer underlays
These give added protection to the carpet against the hard sub-floor during normal walking. Indentations from furniture will be less severe where the carpet is fitted on a firm underlay.
Firmer underlays will prevent excessive vertical movement and stretching of the carpet in use and will therefore help to prevent rucking problems
Examples of firmer underlays include Duralay Treadmore a high-quality crumb rubber underlay made by Interfloor.
Comments on Softer underlays
Soft, low density underlays do not give as much support in heavy wear areas as the carpet pile is effectively squashed against the sub-floor, accelerating wear and appearance changes.
A softer product could eventually collapse under excessive pressure and allow the carpet backing to be distorted, preventing good recovery and making furniture indentations more severe. We would advise against using low density foam underlays of less than 8mm thickness as they are likely to reduce the life of your carpet and mean earlier replacement.
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You are well informed. Felt underlay is a more traditional type and a 42oz weight is used widely in commercial installations because it is hard wearing and firm whilst providing exceptional support to the carpet. It is environmentally friendly as it is made from 100% recycled fibres, and has excellent thermal and acoustic insulation properties.
The main reason you do not often see it available in retail stores these days is because it is not as aesthetically pleasing as more modern rubber and PU underlays and also carpet fitters have to spend more time installing it which ultimately reduces the retailer’s profits.
You are limited to the types and styles of underlay available based upon the tog rating. The combined tog for the carpet and underlay should not exceed 2.5TOG. We sell a range of underlays specifically designed for use with underfloor heating for carpets, laminates and contract use. Please seek advice from the manufacturer of the heating system first as the underlay you purchase could affect the performance of your system.
We recommend ThermalStream underlay for carpets with underfloor heating as this underlay gives the best comfort underfoot yet still allows good heat flow to your carpets.
The best carpet underlay for underfloor heating
ThermalStream Underfloor Heating Underlay
ThermalStream Underfloor Heating Underlay
Our range of underfloor heating underlays for Carpets and Wood Floors can be found at:-
https://www.carpet-underlay-shop.co.uk/collections/underfloor-heating-for-carpets
https://www.carpet-underlay-shop.co.uk/collections/underfloor-heating-for-wood-and-laminate
Underlays we recommend with the highest Tog Rating such as Wool Felt 56oz, and Plushwalk 12mm, Cloud 9 Cirrus, or Cloud 9 Cumulus. The thermal insulation for 56oz Wool Underlay makes it perhaps the best underlay for heat insulation due to its high wool content. Wool felt is among the highest of all our underlays & we would strongly recommend these as felt underlays have a high wool content which naturally have excellent thermal insulation properties.
All our recommended Thermal Underlays can be found at: -
https://www.carpet-underlay-shop.co.uk/collections/thermal-insulation-underlay
Plushwalk 12mm 
Cloud 9 Cumulus 
Thermal Wool Insulation 56oz
When airborne sound arrives at the surface of a wall or floor, some of it is reflected back as an echo, and some of it is transmitted. The remainder is converted into other forms of energy within the material, principally heat. This is known as sound absorption. When airborne sound arrives at one surface of, for example, a floor, some of it is reflected back as an echo, some of it is converted into other forms of energy within the material of the body, and the remainder is transmitted through the material to be radiated as airborne sound on the other side, but at a reduced level. The degree to which this reduction takes place is the sound insulation provided by the floor.
The majority of our underlays listed show the noise reduction properties in terms of dB so that you can make comparisons between the different products. The higher the figure, the greater the noise reduction. Please note that all our acoustic sound insulation figures are based on impact sound and not airborne sound. We recommend Super Velvet with a massive 46dB approx and Plushwalk 12mm with an even better 48dB approx rating.
All our recommended Acoustic Underlays can be found at: -
https://www.carpet-underlay-shop.co.uk/collections/underlay-acoustics
We would recommend using the best underlay which is Plushwalk 12mm which uses memory type foam properties for the ultimate soft feeling underfoot, or go for Cloud 9 Cumulus 11mm both these underlays provide a soft and luxurious feel underfoot and all are guaranteed for the lifetime of the carpet when used in recommended areas.
It depends on your budget but we would recommend an underlay with a higher TOG Rating as this will provide excellent thermal insulation and prevent the transfer of heat through the underlay. It will also help reduce cold air transferring through the underlay from the concrete floor. We recommend Cloud 9 Cirrus, Cumulus or Plushwalk 12mm
Carpet laid over stair nosing’s suffers the heaviest wear in the home. The construction of the carpet is of paramount importance; however, underlays play a very important role. This is primarily to increase the radius over the nosing thus reducing wear concentration. Flat firm underlays offer the best protection such as Cloud 9 Cirrus or Super 10mm Underlay
All our carpet underlays are ideal for use over wooden floor boards, there is a large choice depending on your budget but generally with rubber underlays and felt underlays the heavier the weight the better the quality and with PU underlays the thicker the product the better the quality. We would recommend Super Velvet as the best underlay to level our uneven floors to due its heavy-weight structure.
Super Velvet Underlay
The Best
Waffle rubber underlays gain their name from the pattern on the underside of the underlay, which creates small air pockets that help to provide both comfort and insulation. Whilst waffle underlays make use of trapped air, crumb-rubber underlays like Duralay Treadmore are constructed from small particles of rubber moulded together to produce dense and highly resilient carpet underlays. Crumb-rubber is produced by recycling old car tyres that are then granulated and re-processed which makes it great on the environment.
We would recommend to stick with PU Foam underlays such as Plushwalk as these are the latest to-date underlays giving your carpets the best feeling and softness underfoot.
https://www.carpet-underlay-shop.co.uk/pages/measurement-calculator
We believe its best to have a little excess than buy exactly what you need, because sometimes you may need extra underlay when cutting and piecing into corner areas, which means buying exactly what you need will leave you short! So our advice is to buy Full Rolls or Half Rolls.
Several PU foam underlays can be used with wood block flooring. The Cloud 9 Cirrus and Cumulus or DeepStep are great underlays, but the best underlay is Plushwalk 12mm
Good The Best
Most felt backed carpets are designed specifically to not require underlay. You can still fit this, however due to the thickness it may be too soft underfoot and too thick for grippers/ underneath doorways.
