Almost every portable cabin quotation comes down to one line: the wall panel. The PUF vs EPS panel choice decides how hot the cabin gets in May, how quiet it is next to a working site, how long it lasts, and a large part of what you pay. Everything else — frame, flooring, windows — matters, but not as much as this.
Here is a plain comparison, without jargon.
What the two panels actually are
Both are sandwich panels: an insulating core bonded between two pre-coated steel sheets. The difference is the core.
- PUF (polyurethane foam) — a rigid foam injected between the sheets and cured. It sets hard, bonds tightly to the steel and traps very little moisture.
- EPS (expanded polystyrene) — the material most people know as thermocol. Pre-formed sheets of foam are glued between the steel skins.
Side by side
| Factor | PUF panel | EPS panel |
|---|---|---|
| Heat insulation | Better — noticeably cooler inside | Adequate, weaker in high heat |
| Sound insulation | Better | Moderate |
| Rigidity | Higher — panel feels solid | Lower — can dent more easily |
| Moisture behaviour | Closed cell, resists water ingress | Can absorb moisture at damaged edges |
| Weight | Slightly heavier | Lighter |
| Cost | Higher | Lower |
| Typical life in Indian conditions | Longer | Shorter, especially in coastal humidity |
Where thickness comes in
Panels are supplied in 40 mm, 50 mm, 60 mm and 80 mm. Thickness matters as much as the core material — a 60 mm EPS panel can perform better than a 40 mm PUF panel in some situations. When you compare two quotes, compare core type and thickness together. “Sandwich panel” on its own tells you nothing.
When EPS is the sensible choice
- The cabin is needed for a short project — a few months to a year.
- It is a storage or store room where nobody sits all day.
- The site is in a cooler or drier region and the cabin is shaded.
- Budget is tight and the cabin will be replaced rather than resold.
When PUF is worth the extra
- People sit inside for full shifts — a site office, a security post, a shop.
- The cabin is in coastal or high-humidity conditions.
- You will run an AC and want the cooling to hold.
- The cabin is a long-term asset that may be shifted between sites for years.
The extra cost of PUF is usually recovered through lower running cost of cooling and a longer usable life. On a permanent gate or a multi-year project, it is rarely a close call.
What else to check on the panel line
The core is not the only variable hiding in that one line of the quotation:
- Sheet thickness. The steel skins are typically 0.4 mm to 0.6 mm. Thinner skins dent.
- Coating. Pre-painted galvanised steel resists rust; plain painted sheet does not last the same.
- Roof panel. Roof takes the most sun and rain — it is often specified thinner than the walls, so ask.
- Joints and sealant. Panel joints are where leaks start. Ask what sealant is used and whether joints are capped.
Rock wool: the third option
Where fire performance matters — inside industrial plants, near hot work, in some client specifications — rock wool core panels are used instead. They cost more than both PUF and EPS and are heavier, but they do not contribute fuel in a fire. If your client or safety department has specified a fire rating, this is usually the panel they mean.
Ask for the specification in writing
Before comparing prices, get both suppliers to state core type, core thickness, sheet thickness, coating and roof panel spec in writing. Once those five lines match, the price difference is real. Our comparison with traditional construction covers the wider cost picture.
MK Portable Cabin manufactures office cabins, security cabins, site cabins, shop cabins, container cabins and portable toilets, and has delivered to 300+ clients across India.