PU Foam Underlay

Polyurethane foam is widely used for carpet underlay products because of its cushioning and eco-friendly properties.

The main benefits of using PU underlay for carpets include:

• Underfoot comfort – This soft underlay creates a plush feeling, making floors more comfortable to walk on and rooms feel cosier.  
• Thermal insulation – As foam is a natural insulator, this underlay helps to keep spaces warmer in winter and cooler in summer.
• Noise reduction – Similarly, greater insulation also provides a level of soundproofing, absorbing noise to create a quieter environment.
• Easy installation – Lightweight foam is easier to handle and cut to size than other materials, which is ideal for DIY and professional fitting alike.
• Sustainability – Made from a percentage of recycled foam or offcuts from sofa cushions and mattresses, it is an environmentally friendly choice.

Whether you need foam underlay for a rug or you’re carpeting a whole room, there are various thicknesses, densities, and installation types available.

For more details about this type of underlay, be sure to read our PU foam underlay guide to learn everything you need to know.

The price of PU foam underlay depends on the thickness, density, and quantity you need. At Simply Underlay, our current collection ranges from £3.25m² for a standard 8mm foam carpet underlay to £8.43m² for 10mm foam underfloor heating underlay for carpets.

The majority of these products are available in 15.07m² full rolls, while some are also available in 7.5m² half rolls.

Generally, the thicker the underlay, the more it will cost – meaning an 8mm or 9mm underlay will be more budget-friendly, a 10mm foam underlay will be a little pricier, and an 11mm or 12mm PU foam underlay will have the highest price tag of the range.

For example, Wilsons Plushwalk products aren’t just made from standard PU foam – luxury carpet underlay rolls like these cost more because memory foam carpet underlay provides a plusher experience with better bounce-back, so you’re investing in long-lasting enhanced comfort.

Generally, no. The semi-closed structure of standard PU foam means that underlay made from this material allows some movement of air and moisture vapour, but it is not as porous as other underlay materials like felt or multi-layer membranes.

Polyurethane underlay also often comes with a plastic backing that acts as a vapour barrier. This is designed to prevent damp from rising through the underlay from the subfloor and damaging the flooring above, keeping your floors dry and supported for as long as possible.

In some cases, a PU underlay may be specially designed to be breathable, such as a foam underlay that’s intended for use with an underfloor heating system. This is because underfloor heating underlay must allow warm air to rise and spread through the flooring efficiently.

Not sure whether you need your PU carpet underlay to be breathable or not? You can contact us with any questions you have about our products and their suitability for your installation requirements, and we’ll get back to you soon with expert advice.

While PU foam underlay can last for many years, especially if you choose a thick carpet underlay that takes longer to compress, this material is more suitable for areas with less foot traffic where comfort is a priority – such as living rooms and bedrooms.

This is because softer, bouncier polyurethane foam isn’t as dense as crumb rubber underlay or sponge rubber underlay, so it won’t last as long if you install it in busy areas like hallways, staircases, or commercial buildings.

However, that doesn’t mean you can’t use PU underlay in high-traffic areas at all. In fact, we offer several high-density foam underlay options for use in both domestic and contract installations, including SU Regal Ultra High Density 10mm Underlay and Wilsons ToughStep High-Density 9mm Underlay.

For more guidance on the right foam underlay density for your space, read our guide on how to choose the right carpet underlay, or get in touch!