Anti-slip by room: which class to choose (C1, C2, C3 and the R scale)

Choosing the right anti-slip rating is a matter of safety, but also of regulations and cleaning comfort. The good news is that it comes down to two scales and a table by room.

How slip resistance is measured

There are two common classifications worth knowing:

• Class 1, 2 and 3 (Spanish standard, based on slip resistance Rd in the Technical Building Code). The higher the number, the greater the grip.
• R scale, from R9 to R13 (German classification, measured on a ramp). R9 is the minimum and R13 the maximum grip.

They're not identical, but as an approximate guide: Class 1 ≈ R9–R10, Class 2 ≈ R10–R11 and Class 3 ≈ R11 or higher.

Which class you need in each room

• Dry interior (living room, bedroom, hallway): no special requirement. Polished or matt finish as preferred.
• Kitchen and bathroom (dry area): Class 1–2 (R10). Adds safety without complicating cleaning.
• Shower tray and wet-zone bathrooms: Class 3 (R11+). Essential where there's water and bare feet.
• Terraces, porches and outdoors: Class 3 (R11). Withstands rain and frost.
• Pool edges and communal showers: R12–R13, maximum grip.

The balance: grip vs. cleaning

The more anti-slip a finish is, the more texture it has, and the more noticeable it is when cleaning. That's why you shouldn't "overdo it": using an R13 in a dry living room only complicates maintenance without adding real safety. Choose the class each room calls for, no more, no less.

One project, several finishes

Many porcelain collections offer the same design in a polished/matt finish for interiors and an anti-slip version for the shower and outdoors. This way you can keep the same look from the living room to the terrace, changing only the level of grip where needed. For the shower tray, combine it with what we explain in the how to choose a shower tray guide.

Got doubts about the finish of a specific collection? Ask us and we'll tell you the class of each series, or request a tailored quote.