Choosing the right foam
Most foam that fails was simply the wrong grade for the job. Ten minutes here saves you buying twice.
Density is not firmness
This is the point everyone gets wrong. Density is how much material is packed into the foam — it determines how long it lasts. Firmness is how hard it feels to sit on. A high density foam can feel soft and still last ten years; a low density foam can feel firm and collapse in eight months.
If you are buying seating, buy on density. Firmness is a comfort preference. Density is whether you are doing this again next year.
Which grade for which job
| What you are making | Use this |
|---|---|
| Sofa and armchair seats, daily use | High density foam |
| Sofa backs and scatter cushions | Soft or medium upholstery foam |
| Dining chairs, stools, bench pads | High density or recon |
| Heavy-use or commercial seating, gym matting | Recon (reconstituted) foam |
| Mattresses and toppers | Memory foam |
| Caravan, camper and boat bunks | High density, or memory foam for sleeping |
| Window seats and bay windows | High density, 5–10cm |
| Packaging and acoustic panels | Soft foam or offcuts |
How thick?
- 2.5cm — thin seat pads, packaging, padding a hard surface
- 5cm — dining chairs, window seats, bench pads, light seating
- 7.5cm — the usual choice for a comfortable seat pad
- 10cm — sofa seats, caravan bunks, proper cushioning
- 12.5–15cm — deep sofa cushions, mattresses
Measuring properly
Three rules that prevent almost every returned order:
- Measure the old foam, not the cover. Covers stretch. Foam does not.
- Measure flat, uncompressed. Lay it out. Do not measure it in place under a cushion.
- Add 1cm if the cover is loose. Foam slightly larger than the cover fills it properly and stops that wrinkled look. Too small and it slides about.
For a bay window, measure the depth at the narrowest point and the length at the widest. Bay windows are almost never square, and this is where most orders go wrong.
Fire retardant foam
If you are reupholstering furniture that will be sold, or working on anything commercial — a rental, a café, a hotel — you need CMHR fire retardant foam to meet UK furniture regulations. For your own furniture in your own home it is not legally required, but it is not expensive and it is worth it.
Still not sure?
Send us the dimensions and tell us what it is for. We would rather spend two minutes getting it right than send you the wrong thing.