Mr Resistor
Mr Resistor
Home Lighting Design

Buying guide

Bathroom zones & IP ratings, made simple.

Bathrooms are split into zones by how likely a fitting is to meet water. Each zone needs a minimum IP rating — here's what goes where.

Zone 0

Inside the bath or shower IPx7 minimum

The interior of the bath tub or shower tray itself.

Low-voltage only — SELV 12V, with the transformer outside zones 0–2.

Zone 1

Above, up to 2.25m IPx4 minimum

Directly above the bath or shower, to a height of 2.25m.

Mains or SELV 12V (source outside the zones).

Zone 2

0.6m around, and above 2.25m IPx4 minimum

A 0.6m band beyond zone 1, and the area above 2.25m.

Mains or SELV 12V (source outside the zones).

Outside the zones there's no formal IP requirement, but in a steamy room a moisture-resistant fitting (IP44+) is always the safer choice. Any SELV supply unit must sit outside zones 0–2.

Reading an IP rating

"IP" plus two digits: the first is protection against solids, the second against water. Higher is more protected.

First digit — solids

0 No special protection
1 Objects over 50mm (e.g. a hand)
2 Objects over 12mm (e.g. a finger)
3 Tools and wires over 2.5mm
4 Solids over 1mm
5 Dust-protected
6 Fully dust-tight

Second digit — water

0 No special protection
1 Dripping water
2 Dripping at up to 15°
3 Sprayed water (to 60°)
4 Splashed from any direction
5 Water jets
6 Powerful jets
7 Immersion to 1m
8 Continuous submersion

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