Two jobs, one family of material
Carpet backing is part of the carpet. It is bonded to the carpet during manufacture and travels with it, giving the finished product stability, body and a consistent base for the adhesive or the fitting method.
Underlay is laid loose on the subfloor before the floor covering goes down. It is not part of the carpet, it can be replaced independently, and it is chosen for comfort, impact sound and for levelling out minor irregularities in the floor beneath.
Primary and secondary backing
| Feature | Primary backing | Secondary backing |
|---|---|---|
| Where it sits | The sheet the pile is tufted through | Laminated to the back of the tufted carpet |
| Main job | Carrying and holding the tufts in place | Dimensional stability, body and a fitting surface |
| What it must have | Consistent structure that needles and tufts cleanly | Strength, stability and a surface that bonds reliably |
| Typical nonwoven role | Light to medium weight felt | Medium to heavy weight felt |
What the felt contributes to a carpet
- Dimensional stability, so the carpet keeps its shape and does not creep or curl
- Body underfoot, which changes how the carpet feels in use
- A uniform base that takes adhesive consistently across the roll
- Help with sound absorption and impact noise within the floor build-up
- Some thermal insulation, which makes a hard floor feel warmer
- Protection for the pile from grit pressed up from the subfloor
Our carpet backing felt is made in polyester and PP for exactly this role, in wall-to-wall carpet, rugs, exhibition carpet, automotive carpet and floor mats.
Underlay: under carpet, laminate, vinyl and wood
An underlay has to do three unglamorous things well: cushion the step, take the edge off impact noise, and present a smooth, stable surface so small subfloor imperfections do not read through the finished floor. A needle punched felt does all three because the structure is compressible but recovers, and because the sheet is uniform across its width.
The same material suits carpet, laminate, vinyl and wooden flooring, in residential rooms, offices, hotels and exhibition spaces. Our flooring underlay felt is supplied in rolls that cut and lay flat.
A word about acoustic and thermal numbers
Felt helps reduce impact noise and adds thermal resistance, but a rating belongs to a whole floor assembly, not to a fabric. Impact sound performance depends on the subfloor, the fixing method, the floor covering and the detailing at the edges. If your project needs a stated figure, it has to come from a test on the assembly you are actually building.
What we can do is make the material to the weight, thickness and density your specifier asks for, and supply samples so the build-up can be tested as designed.
Choosing weight and fibre
Weight drives almost everything you feel in a floor: a heavier felt is firmer and more stable, a lighter one is softer and cheaper to ship. Backing for a commercial carpet and underlay for a hotel corridor sit at different points, and both are made to order across our 100–1200 GSM range. GSM in nonwoven fabric explains how weight, thickness and density relate.
On fibre, polyester gives better resilience and recovery, which matters where a floor is walked on constantly; PP — virgin or recycled — is the economical choice and handles damp well. Polyester vs polypropylene sets out the trade-off in full. Where the felt is visible, as in exhibition flooring, multi-colour needle punched felt is made to a colour.
What to settle before you order
- Whether the felt is a carpet backing, an underlay, or both
- GSM, thickness and density, or the performance the floor has to deliver
- Fibre — polyester, PP (virgin or recycled) or a blend
- Roll width and roll length, matched to your laminating line or to the room
- Colour, where the material will be seen
- How it will be processed — laminated, bonded, cut to size or supplied in full rolls
Rolls are produced at 5.0–5.2 m width and can be cut down. Send the application and the figures you have through the enquiry form; samples are available on request so the material can be trialled in your own lamination or fitting process.
Questions
What is carpet backing felt made of?
Needle punched carpet backing felt is usually made from polyester, polypropylene or a blend of the two. Polyester gives better resilience and recovery; PP is the more economical option and handles damp well. We supply both, and blends.
What is the difference between carpet backing and underlay?
Backing is bonded to the carpet during manufacture and is part of the finished product. Underlay is laid separately on the subfloor before the covering goes down, and can be replaced on its own. Backing is specified for stability and bonding; underlay for comfort, impact sound and a smooth base.
What GSM should I use for carpet backing or underlay?
There is no single figure — a secondary backing for a commercial carpet and an underlay for a residential room sit at very different weights. Material is made to order from 100 to 1200 GSM, so tell us the application and the feel or stability you need and we will recommend a weight.
Can nonwoven underlay go under laminate and vinyl?
Yes. The same felt is used under carpet, laminate, vinyl and wooden flooring. Confirm thickness against the floor covering manufacturer’s installation instructions, since some systems set a limit on underlay thickness or compressibility.
Can the felt be supplied in a colour or a cut width?
Colour, GSM, thickness, width and roll length are all made to requirement. Rolls are produced at 5.0–5.2 m and can be cut down to the width your line or your layout needs.