Retrofitting Sauna Lighting: How to Install New Lighting in an Old Sauna Easily?

Renovating an old sauna often begins with the easiest and most impactful element: the lighting. Over the years, a yellowed or dimmed bathing space brightens and becomes more inviting when the old grille fixture is replaced with a modern solution. However, many postpone updating the lights, fearing a laborious and expensive renovation involving panel removal. Current installation methods and technology make it possible to update sauna lighting easily as a retrofit installation. Stylish and atmospheric lighting can be built entirely on top of surfaces or discreetly without breaking into structures.

How is sauna lighting retrofitted?

Retrofitting sauna lighting does not require removing wall panels or running electrical cables inside walls. When the goal is to update sauna lighting effortlessly, the best approach is to utilise existing routes and introduce light sources indirectly. In practice, new light lines are often installed under benches or behind backrests, where light reflects gently off wooden surfaces without dazzling bathers.

This surface routing is easy because modern lighting systems use low-voltage 12 or 24 volt systems. Low voltage makes installation safe in humid spaces and enables the use of slender cables. Wires can be run discreetly, for example, protected by bench structures or behind corner trims without the need to chase into walls. To ensure safety, the power supply is typically positioned on the dry side or down under the benches in a splash-proof enclosure.

Surface cabling commonly uses heat-resistant silicone cables that won't become brittle in hot air. When cables are run beneath bench structures, they remain protected from direct steam water and the hottest vapour. If you want to retrofit sauna lighting entirely without an electrician, ready-made sets with plug connections are available on the market. Another, more durable option is to leave the power supply connection to an electrical professional, allowing control to be integrated into the home's other lighting control systems.

Wireless control solves the traditional challenge of positioning light switches. Using a wireless controller eliminates the need to run new switch wires through walls. A battery-powered or magnetically mounted controller can be installed anywhere, for example, beside the sauna door or in the changing room. This saves installation time and enables dimming of light output according to current needs. If you want to ensure that the LED strip, power supply and control are compatible, our customer service team will happily help assemble the right components for your specific sauna. Also read our sauna lighting guide, which compares suitable LED strips for saunas.

Can LED strip be installed on the sauna ceiling?

The ceiling area is the most challenging location for electronics in a sauna, as hot air rises upwards. Ordinary LED strips begin to deteriorate quickly if continuously exposed to temperatures above 80 degrees. At the sauna ceiling level, temperature often rises to 100–120 degrees, which exceeds the tolerance of ordinary LED components. Direct installation on the ceiling surface without proper protection often leads to light failure.

When designing durable overhead lighting, two main factors must be considered: heat conductivity and moisture protection. Components intended for sauna upper areas must have high heat resistance. Valotehdas's PISTEETÖN SAUNA LED strip withstands up to 125°C and is IP65-protected, making it suitable even for the ceiling area. Moisture protection ensures the strip won't be damaged by condensing steam or splash water.

When selecting LED strip for the ceiling area or its immediate vicinity, high strip quality alone is not sufficient. Heat radiating from the diodes must be able to dissipate freely. If LED strip is glued directly onto a wooden surface, the wood acts as insulation and traps heat inside the strip, causing joints and diodes to burn out prematurely. An aluminium mounting profile finishes the appearance whilst serving as an essential cooling element. The profile effectively conducts heat away from the diodes and prevents them from overheating.

The most durable and trouble-free sauna lighting is often achieved by positioning LED strips slightly lower, for example behind backrests or under the top bench. This creates a pleasant reflection and spares components from the hottest air. In indirect installation, the strip is usually placed behind a downward-facing lip. This way, hot steam doesn't condense directly onto the profile surface, and light spreads gently throughout the space via the wall.

What is the best colour temperature for a sauna?

Choosing the right colour temperature determines the sauna's appearance and atmosphere. Colour temperature is expressed in Kelvins (K). The lower the Kelvin value, the warmer and more reddish the light. A higher value means a cooler, more bluish tone. In a sauna, the light tone directly affects the space's feel and relaxation.

The traditional sauna atmosphere is achieved with warm light in the range of 2200K–2700K. This soft yellow light mimics the glow of a traditional fire. Dim light helps the body and mind relax. Excessively bright or cool light can make the sauna feel sterile.

Light tone also affects how the sauna's wooden surfaces appear. Warm light emphasises the natural tones of tar-treated alder, heat-treated aspen and other dark wood species. If the sauna has pale aspen or grey weathered wood, a more neutral 3000K light often works best. It keeps the overall appearance fresh whilst maintaining cosiness.

Adjustable CCT lighting (Color Correlated Temperature) enables flexible changing of light colour temperature. This is useful, for example, during cleaning when light can be adjusted to bright white. During steam bathing, the tone is dimmed to warm yellow.

Retrofitting sauna lighting is an effortless way to increase the space's comfort and safety. When installation uses low-voltage systems, safe surface routing and heat-protected materials, the lighting will last for years. Carefully selected light direction and tone complete the result and make your home sauna even more functional.