Underlay 101: When to Upgrade Your Underlay for Comfort and Insulation

You may not be able to see underlay, but it influences comfort, acoustics, insulation, and even the longevity of the flooring above it.

Homeowners unknowingly keep old underlay far past its effective lifespan, causing issues like uneven flooring, reduced insulation, and poor comfort underfoot. To make informed decisions, it’s useful to break down the lifespan of different types of underlay and explore how often each should be replaced.

Carpet Underlay Lifespan: How Often Should Carpet Underlay be Replaced?

Good-quality carpet underlay lasts around 7–15 years, depending on the material and the level of use. Foam underlays tend to feel soft initially but can break down quicker, especially in high-traffic areas such as stairs, hallways, and landings. Rubber underlay, especially the dense waffle or crumb varieties, tends to offer better resilience and may have a longer lifespan, sometimes even outlasting the carpet itself.

However, the true test lies in how the underlay performs day-to-day. If it feels flat, uneven, or no longer provides cushioning, it’s already past its best. Old, degraded underlay can make new carpet feel prematurely worn, and it can even contribute to reduced heat insulation and increased household noise.

How Long Does Carpet Underlay Last Under Heavy Use?

Heavy use tends to shorten the lifespan of underlay significantly, often bringing it closer to the 5–8-year range. Staircases experience intense pressure and repetitive impact, meaning stair underlay often needs replacing sooner than underlay in bedrooms or living rooms. If a carpet on the stairs feels thin or if the steps feel harder underfoot, the underlay is likely worn out.

For heavy-use areas, investing in a dense, high-quality rubber or PU underlay can extend the lifespan and improve comfort, but even then, replacement eventually becomes necessary.

Laminate Underlay Lifespan: A Different Set of Rules

Carpet underlay and laminate underlay are not the same, and neither are their lifespans. If you have hard flooring, you may be wondering how long does laminate underlay last, as laminate behaves differently from carpet.

Laminate underlay typically lasts anywhere from 10–25 years depending on the type and whether the room experiences moisture. Foam laminate underlays may degrade faster, especially if they are constantly under pressure, whereas fibreboard or rubber underlays tend to have better structural longevity. If the floor begins creaking, feels uneven, or shows signs of movement between boards, the underlay may be compressed or damaged.

Moisture is the number one enemy of laminate underlay. Any spillages, leaks, or humidity issues weaken the material, causing it to swell, warp, or break down. In these situations, replacement becomes necessary long before the expected lifespan has passed.

Should You Replace Underlay with New Flooring?

One of the most common flooring questions is whether or not old underlay can be reused.

Underlay ages even if it still looks intact. Compression happens gradually, and although the surface may appear fine, its ability to cushion, insulate, and support new flooring is often diminished. Installing new flooring on top of old underlay usually results in:

• Reduced comfort
• Poor acoustics
• Quicker wear on the flooring above
• Visible imperfections showing through
• Reduced insulation or draught issues

If you’re making the investment in new carpet or laminate, it makes practical and financial sense to replace the underlay at the same time. The marginal extra cost pays off significantly in performance and lifespan.

Signs You Need to Replace Your Underlay

Knowing when to replace underlay becomes easier when you understand the warning signs:

• A noticeable lack of cushioning
• Uneven or bumpy flooring
• Crumbling or dusty underlay residue
• Musty smells (often caused by moisture in old underlay)
• Creaking sounds under hard flooring
• Carpet wearing out faster than expected

If you have experienced any of these, your underlay is no longer performing effectively, and replacement should be considered.

How to Get the Most from Your Underlay

Although underlay has a natural lifespan, a few simple practices can extend it:

• Choose the right underlay for the flooring type
• Avoid moisture exposure
• Use dense, high-quality materials
• Replace underlay in high-traffic areas more frequently
• Check compatibility with underfloor heating

By choosing the right products and ensuring proper installation, you can enjoy better performance and a longer lifespan from both your underlay and flooring.

Whether you’re wondering how long does laminate underlay last, or how often should carpet underlay be replaced, the answer always comes back to quality, use, and maintenance. The simplest rule is this: If you’re installing new flooring, replace the underlay. Your floors will feel better, last longer, and perform the way they were designed to.

Still unsure about your underlay? Speak to an expert. We’d be happy to help.