Waterproof Luminaires

What is a waterproof luminaire?

A waterproof luminaire is a light fitting with an increased IP rating, built specifically for rooms with high humidity, splash water or condensation. Unlike a standard fitting, the housing is sealed against moisture ingress, usually via a gasket running between the base and the cover. Typical materials are polycarbonate (PC) or PMMA for the housing, combined with stainless steel or plastic clips for the closure.

Waterproof luminaires are used in cellars, wash rooms, garages, car parks, bathrooms and production halls – anywhere a standard indoor fitting would fail over time.

Buying criteria: what to check on a waterproof luminaire

These are the criteria that get you to the right fitting for your application:

IP rating

The IP rating shows how well the housing is sealed against dust and water, and it's the single most important criterion. For most waterproof applications, IP65 is enough (dust-tight, protected against water jets from any direction). Where the fitting sits in direct contact with water, for example above a shower, you need at least IP67. More on the individual ratings in our IP protection class wiki article.

Impact resistance (IK rating)

Besides water and dust protection, mechanical strength matters in workshops, car parks or storage rooms. The IK rating indicates how resistant the housing is to impact. For areas with a higher risk of knocks or impact, IK08 or above is recommended.

Material and build quality

The housing is usually made from PC or PMMA. PC is more impact-resistant and heat-stable, PMMA offers better light transmission. It's also worth checking the closure clips: stainless steel clips don't corrode and hold up better than plastic ones, especially if the fitting is opened regularly for lamp replacement.

Colour temperature and CRI

For workshops and storage rooms, neutral white (4000K) is the usual choice. In wash rooms or bathrooms, warm white (3000K) feels more comfortable. Where colours need to be judged accurately, for example in a paint shop, the CRI (colour rendering index) should be at least 80.

Output and luminous flux

The wattage you need depends on room size and ceiling height. As a rough guide: 20 to 40 W is usually enough for cellars and storage rooms, while workshops and car parks with higher ceilings typically call for 40 to 80 W. The luminous flux in lumens matters more than the wattage – look for at least 100 lm/W for current LED efficiency.

Length

Waterproof luminaires typically come in 60, 120 and 150 cm lengths, following the standard sizes of T8 and T5 fluorescent tubes. The length depends on the available mounting space and the illumination you need – several shorter fittings give you more flexibility in positioning, while a continuous 150 cm fitting produces a more even line of light.

Wiring

For daisy-chaining several fittings, a waterproof luminaire with through-wiring is worth choosing: two cable entries let you loop the mains supply from fitting to fitting without extra junction boxes. Older waterproof luminaires running on T8 tubes can also be converted to LED without much effort – more on that in our guide to converting fluorescent tubes to LED and in the LED tubes category.

Sensors and dimming

For cellars, garages and utility rooms with only occasional use, a waterproof luminaire with a built-in motion detector, or a separately fitted sensor, is worth considering. Make sure the sensor itself is rated for the damp environment. More on choosing one in our indoor motion detectors category.

Applications at a glance

Requirements for IP rating, impact resistance and colour temperature vary considerably depending on where the luminaire is installed:

For explosion-hazard areas such as paint shops or fuel stations, a standard waterproof luminaire isn't enough – you'll need an EX-protected luminaire to ATEX instead.

FAQ: Common questions about waterproof luminaires