Carpet Tile Backing Systems Compared: PVC, Polyolefin, Bitumen, PU Cushion and PET

Pei Xiaochuan✓

Chairman, UNIJOY · 15 years in carpet tile·27 July 2026·7 min read

Technically reviewed by Pei Xiaochuan, Chairman

TL;DR

The backing is the structural half of a carpet tile, and it decides dimensional stability, moisture tolerance, underfoot comfort and impact-sound performance far more than the yarn does. No single backing wins outright. PVC and bitumen hardbacks are chosen for dimensional stability and heavy traffic; PVC-free polyolefin backings (EcoWorx, EcoFlex) trade a little of that for much lower weight and cleaner recycling; PU or foam cushion and recycled-textile felt add comfort and cut impact noise. The right question is not "which backing is best" but "which backing suits this subfloor, this traffic and this acoustic goal" — and then: what does the tested construction actually document?

Large commercial lounge floor covered in grey carpet tile with a green accent zone — a wide expanse where backing performance under traffic shows

1. What the backing actually does

A carpet tile has two halves. The face — the yarn you see and walk on — gets most of the attention. The backing is the structural half, and it quietly decides how the tile behaves once it is on the floor: its dimensional stability, how it tolerates a damp subfloor, how it feels underfoot, how it handles rolling loads, and how much impact noise it passes to the room below.

That is why two tiles with a similar face yarn can perform quite differently after installation. It also means a material label — “PVC”, “soft backing” — is only a starting point. What matters is the whole build-up and what it has been tested to do.

The layer this guide is about is the secondary backing system at the bottom. The thin fibreglass scrim just above it is what most often provides the dimensional stability that lets a tile lie flat and tight-butted — the property tested by the “Aachen test” (ISO 2551 / EN 986).

2. The five backing families, compared

Marketing organises backings by brand name; a buyer is better served by the generic families. There are five worth knowing. The table sets out how they tend to trade off — these are family tendencies, not the spec of any one product, and a specific tile’s tested values always govern.

Backing family	Dimensional stability	Moisture tolerance	Comfort / acoustics	Recycled & weight
PVC (thermoplastic)	Very good — often over a fibreglass veil	Good moisture resistance	Firm; hardback, limited cushioning	Heavier; plasticiser & end-of-life questions
PVC-free polyolefin (e.g. EcoWorx, EcoFlex)	Good — over a fibreglass scrim	Moisture-impervious grades available	Firm hardback	~25–40% lighter than PVC; closed-loop recyclable
Bitumen / PVB hardback	Excellent — a benchmark for stability	Waterproof / moisture barrier	Firm; no cushioning	Often high recycled content; heavy & stiff
PU / foam cushion	Good, product-dependent	Best kept off very wet subfloors	Best comfort; strong impact-sound gain	Adds weight & thickness for comfort
Recycled-textile / PET felt	Good	Moderate	Softer underfoot; good absorption	Recycled PET; heavier grades add comfort

Read the table as “where each family usually starts”, not as a scoreboard. A well-engineered PVC-free tile can match a PVC one for stability; a cushion tile can be specified for a corridor if the product data supports it. The families narrow the field — the tested construction settles it.

3. Backing and sound: two different things

“Acoustic backing” gets used loosely, so it helps to separate the two things a backing can do for sound:

Sound absorption (NRC) — how much airborne sound the floor soaks up in the room. Driven mostly by the face and by a permeable cushion beneath it.
Impact sound (IIC in the US, ΔL_win Europe) — footfall and dropped-object noise transmitted to the room below. This is where backing, and cushion in particular, does its clearest work.

Independent data backs this up. In The Carpet and Rug Institute’s acoustics testing on a concrete floor-ceiling assembly, the impact rating climbed as follows:

Assembly (concrete slab)	Impact rating (IIC)
Bare slab	34
Carpet alone	53–70 (rises with pile weight)
Carpet + cushion	up to ~80 (rises with cushion weight)

The European framework expresses the same idea differently: impact-sound improvement is measured per ISO 10140-3 and weighted into a single ΔL_wfigure, where a cushioned carpet backing can add on the order of +8 dB. The two systems (IIC and ΔL_w) are not interchangeable, so match the number to the standard your project uses. We go deeper on room and impact acoustics in the carpet tile acoustics guide.

Open-plan office with workstations and grey carpet tile broken by a green accent path, over an exposed-services ceiling — In an open-plan office the backing is doing invisible work all day — holding tiles flat under chair castors, absorbing footfall, and coping with whatever the subfloor throws at it. None of that is visible in the face yarn.

4. UNIJOY’s backing, stated as a construction fact

To be concrete rather than generic: UNIJOY supplies a TGLITE soft backing, a textile-based system incorporating recycled content, alongside conventional PVC-backed constructions. That is a statement about how the tile is built — not a universal performance claim, and not a reason to skip the documents.

The honest way to use any backing fact, ours included, is the same: ask for the current spec sheet for the exact colour and format you are quoting, and the test report for that complete construction. A backing name tells you the family; only the documented build-up tells you what it will do on your floor.

5. How to choose for your floor

Work from the floor back to the backing, not the other way around:

Heavy traffic, rolling loads, dimensional priority → a hardback (PVC, PVC-free polyolefin or bitumen) with documented stability.
Comfort and quiet underfoot, floors above occupied space → a cushion or recycled-textile backing, with the impact-sound result to prove it.
Damp or unpredictable subfloor → a moisture-tolerant hardback; keep soft cushion off very wet slabs.
Sustainability-led brief → compare recycled percentage, take-back / recyclability and total weight; do not accept a bare “eco” label.
Every case → confirm the backing on the quoted SKU, and get the test report for that exact construction.

The right backing is the one whose documented construction matches the project. Choosing by a material label alone is how a technically sound product ends up a poor fit for a particular floor.

Frequently asked questions

Is PVC backing always the best choice?

No. PVC hardbacks are a strong, well-proven option where dimensional stability, moisture resistance and heavy traffic matter, and they are usually the lowest-cost route. But they are heavier, can stiffen in cold, and carry plasticiser and end-of-life questions — which is exactly why PVC-free polyolefin backings exist. The correct choice depends on your subfloor, traffic, comfort target and sustainability goals, not on a single 'best' label.

Does a soft or cushion backing automatically mean better acoustics?

It reliably improves impact sound — footfall transmitted to the room below — and independent data supports this: on a concrete slab, adding cushion under carpet raised the impact rating (IIC) substantially. But acoustics has two halves. For in-room sound absorption (NRC), a permeable open-cell cushion helps while a dense one can actually help less. And any acoustic figure belongs to a specific tested build-up, so ask for the report and the standard rather than inferring performance from the word 'soft'.

What is dimensional stability and how is it tested?

It is the tile's resistance to shrinking, expanding, curling or distorting out of plane under changes in water and heat — the property that keeps tiles tight-butted and flat without relying on adhesive. It is assessed by the 'Aachen test', standardised as ISO 2551 and EN 986. Ask for the result against the named standard rather than a numeric tolerance quoted out of context.

Which backing is most sustainable?

There is no single answer, because 'sustainable' spans recycled content, recyclability and weight (which drives freight emissions). PVC-free polyolefin backings are marketed for closed-loop recyclability and lower weight; bitumen backings often cite high recycled content; recycled-textile felt uses recycled PET. Ask for the specifics — recycled percentage, whether the maker takes the product back, and the total tile weight — rather than a generic 'eco' claim.

Can two tiles with the same yarn perform differently?

Yes, and this is the core point of the guide. The backing determines how the finished tile handles traffic, rolling loads, moisture and installation. Two tiles with a similar face yarn but different backings can behave quite differently once installed, so treat the backing as part of the specification and get documentation for the exact combination supplied.

Sources & further reading

Figures attributed to other manufacturers are their own published values, quoted for context. Different laboratories, sample build-ups and substrates are not directly comparable.