"What floor should I put down?" has no single correct answer: it depends on whether the area is damp, how much traffic it will bear and whether a specific anti-slip regulation must be met. Choosing the wrong material is a mistake that can't be fixed without lifting the whole floor.
Slip-resistance class isn't optional
On porcelain paving, the slip-resistance class (R9 to R13 under the CTE-DB-SUA) indicates how much grip the piece gives when wet, and it isn't just an aesthetic matter:
- R9-R10 — dry interior (living room, bedrooms).
- R11 — damp interior areas (bathrooms, kitchens).
- R12-R13 — outdoors or ramps.
Installing an R9 piece on a terrace or in a bathroom breaches the regulatory requirement for the space, beyond the real risk of slipping.
Porcelain: format and cutting margin
- Standard format (30×30 to 60×60 cm): 10% margin for cuts and breakage.
- Large format / XXL slab (75×75 cm or more): 12% margin, because a breakage on the final cut is a whole piece lost, not a simple offcut. From 90×90 cm it's wise always to lay with C2 S1 adhesive and a levelling system, and allow more labour time: handling the piece is slow.
Example: for a 25 m² living room with 60×60 porcelain: 25 × 1.10 = 27.5 m² to buy. This is the same calculation the PresupuestoYa calculator applies automatically for the Floor Layer trade.
Laminate, solid wood and vinyl: they're not interchangeable
| Material | Margin | Suitable for damp areas | Key detail |
|---|---|---|---|
| Laminate flooring | +8% | No | 10 mm perimeter expansion gap, hidden under the skirting |
| Solid wood flooring | +10% | No | Acclimatise 48-72h in the room before installing |
| Vinyl / SPC flooring | +8% | Yes | Water-resistant mineral core, suitable for bathrooms and kitchens |
The important difference between laminate and SPC vinyl is moisture: SPC, having a mineral core, can be installed in bathrooms or kitchens without problem; traditional laminate cannot. Always check the product data sheet before installing in a damp area.
With laminate flooring, don't skip the perimeter expansion gap: without that margin of about 10 mm against the wall, the floor has nowhere to expand with changes in humidity and can end up lifting ("tent effect").
Frequently asked questions
Can I put laminate flooring in a bathroom? It isn't recommended: traditional laminate isn't suitable for damp areas. For that room, an SPC vinyl with a water-resistant core or R11-class porcelain are the right options.
What's the difference between R10 and R11? R10 is for dry interiors; R11 is designed for damp interior areas such as bathrooms or kitchens, with more grip when wet.
Why does solid wood flooring need to acclimatise before installation? Because if it's installed fresh from a warehouse with very different humidity from the home, it is the most common cause of it opening up or cupping months later.
Conclusion
Choosing the right floor according to the room's humidity and traffic —and not just for looks— avoids a problem that can't be fixed without lifting the entire flooring. Calculating the material margin according to format and system also gives a tight quote from the first order.
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