A chair that already shows a hollow after a few months, or a sofa seat that feels hard yet gives little support: the cause often lies in the wrong choice of foam. The question of foam rubber: cold foam versus polyether therefore comes up regularly when reupholstering furniture. Both materials have their place in the upholstery workshop, but they clearly differ in comfort, service life, ventilation and price.
If you are rebuilding a dining chair, sofa, caravan interior or loose seat cushions, you don't automatically have to choose the most expensive foam. The right choice depends on the load, the seat feel you want and the construction of the furniture. With the right combination of foam, Dacron and a good upholstery fabric, even a worn piece of furniture can get a comfortable, professional result.
What do we mean by foam rubber?
In practice, the term foam rubber is often used for all kinds of furniture foam. Strictly speaking, foam rubber is a latex-based material, but in furniture upholstery it usually means polyurethane foam. This includes polyether and cold foam, among others.
So they are not two names for exactly the same product. Polyether is the familiar, economical basic foam. Cold foam, also called HR foam, is a high-quality foam with a more open cell structure and greater resilience. That structure determines how the foam reacts when someone sits on it, how quickly it springs back and how long it keeps its shape.
Density is usually indicated by an SG value, which stands for specific gravity. A higher SG value generally means more material per cubic metre and often better durability as well. Still, that value doesn't tell you everything: firmness, raw material quality and application are at least as important.
Foam rubber: cold foam versus polyether in practice
The most noticeable difference is in resilience. Polyether springs back, but less powerfully than cold foam. With intensive use, polyether will sag a little sooner or take a permanent impression, especially if a low quality or too thin a layer is chosen. For a back cushion, decorative cushion or a chair that is used occasionally, however, that can be perfectly fine.
Cold foam distributes pressure better and recovers faster after loading. As a result, a sofa seat feels fresh and supportive for longer. The material is also more breathable. That is pleasant for thick seat cushions, mattresses, lounge furniture and furniture that is sat on for long periods every day.
| Property | Polyether | Cold foam |
|---|---|---|
| Price level | Economical | Higher, but more durable |
| Resilience | Average | High |
| Shape retention | Good with light use | Very good with intensive use |
| Ventilation | Less open structure | Open and better ventilating |
| Seat feel | Often slightly firmer at first | Resilient and supportive |
| Suitable applications | Backrests, occasional seating, padding | Sofa seats, mattresses, heavily used chairs |
A common mistake is to look only at firmness. Hard foam is not automatically better. A very hard seat can become uncomfortable, while a seat that is too soft gives insufficient support and wears out sooner. The right balance depends on the thickness of the foam, the springs or webbing under the seat and the weight the furniture has to bear every day.
When is polyether the smart choice?
Polyether is a practical, competitively priced foam for many projects. Especially for DIYers repairing a single chair, covering a headboard or renewing back cushions, it is often a logical basis. It is easy to cut, glue and work with.
Polyether works particularly well in backrests. There is generally less pressure there than on a seat, and extremely high spring comfort is less necessary. As a padding layer under Dacron, on armrests or for temporary and lightly used furniture, polyether is also a fine choice.
Do pay attention to the quality, though. A cheap, low SG value may seem attractive, but for a seat used every day it is usually a false economy. The foam flattens more quickly, so the fabric can loosen and the furniture has to be opened up again. So for a seat, always choose a quality that suits the load.
Polyether for dining chairs
With dining chairs, the choice depends heavily on the use. For chairs only used at dinner, a decent polyether can do an excellent job. Do you have a large family, do you often work at the dining table, or are the chairs used intensively in hospitality or an office? Then cold foam often pays for itself in a longer service life and more consistent seating comfort.
Thickness is also decisive. A thin seat needs a material that gives enough support without becoming rock-hard. A thicker seat offers more room to work with different firmnesses and comfort layers.
When is cold foam the better choice?
Cold foam is the better choice when comfort and durability come first. Think of sofa seats, armchairs, camper cushions, boat cushions, mattresses and contract furniture. If you are reupholstering a quality sofa, you usually don't want to replace the seat again after a short time. That is exactly where cold foam makes the difference.
Thanks to its open cell structure, the seat stays better ventilated. That reduces the stuffy feeling that can arise from sitting for a long time. Cold foam also offers more point elasticity: it gives where pressure occurs without the whole seat sinking straight away. As a result, it feels supportive, even when you sit for longer.
Cold foam is not always softer than polyether. It can actually feel firm, especially in a higher firmness grade. The difference is that the material reacts more dynamically. You sink in in a controlled way and get resilience back when you move or stand up.
For sofas and armchairs
For a sofa or armchair, cold foam is usually the safest investment, especially for loose seat cushions. Choose the firmness based on the seating comfort you want and combine the foam with Dacron. This soft fibre layer around the foam improves the transition to the upholstery fabric, reduces friction and gives the seat a fuller appearance.
For a more luxurious, slightly softer look, a build-up with a firmer core and a comfortable top layer can be interesting. That does require attention to the total thickness and the fit of the existing or new covers. Too much volume can put seams under strain or stop a cushion from fitting neatly in the frame.
Look beyond the foam
Even the best cold foam won't fix worn suspension. So when reupholstering, always check the complete base: webbing, zigzag springs, spring clips, the wooden frame and fixings. If the base gives too much, a new layer of foam will still feel too soft and wear faster.
The upholstery also plays a part. A thick bouclé, corduroy or chenille gives a different seat feel from smooth faux leather or tightly woven upholstery fabric. Faux leather and Skai often need a neat layer of Dacron, because irregularities show more quickly. With a coarse upholstery fabric, a slightly more rounded finish can look very good.
Measure the old foam carefully before you order. Record the length, width and thickness, but also assess how much the current foam has sagged. An old cushion 8 centimetres thick may originally have been 10 centimetres. So use the existing size as a starting point, not as an absolute truth.
Which choice suits your project?
For a budget-friendly backrest, padding or lightly used chair, polyether is a reliable, practical solution. For a sofa seat, armchair, mattress or furniture that will be used intensively for years, cold foam offers noticeably more comfort and shape retention. The price difference is real, but so are the differences in service life and daily seating comfort.
Torn between two qualities? Then look at the furniture first, not just the foam. How often is it sat on, how thick can the filling be and what support does the base provide? With those answers you can choose more precisely. At BLADI upholstery fabrics we are happy to help match foam, Dacron and upholstery material, so your furniture is not only beautifully upholstered, but also comfortable to sit on again.
