Sauna Materials & Supplies for Custom Saunas in Sydney: A Complete Guide

Building a custom sauna in Sydney is as much about material selection as it is about design. The timber species, heater type, glass configuration, and accessories you choose will define the quality, longevity, and daily experience of your sauna for years to come. Sydney's climate — humid summers, mild winters, and coastal salt air in many suburbs — also introduces specific material considerations that don't apply in cooler, drier climates.

This guide covers every major material category for a custom sauna build, with recommendations tailored to Sydney conditions.

Sauna Timber: The Most Important Decision

Timber is the defining material of any sauna — it affects the look, the feel, the heat performance, and the longevity of the installation. Not all timbers are suitable for sauna use, and in Sydney's humid climate, stability and moisture resistance are especially important.

Western Red Cedar

The most widely used sauna timber in Australia, Western Red Cedar is prized for its natural oils, which provide excellent resistance to moisture, warping, and decay. It's lightweight, easy to work with, and has a warm reddish-brown tone that deepens beautifully over time. Its natural aroma is a bonus — the distinctive cedar scent is part of the sauna experience for many users. Well-suited to both indoor and outdoor Sydney installations.

Thermory Ash (Thermally Modified Timber)

Thermally modified timber has become our top recommendation for Sydney's coastal and humid-zone properties. The thermal modification process — heating the timber to high temperatures in a low-oxygen environment — removes the sugars and resins that attract moisture and biological activity, resulting in a highly stable, dimensionally consistent timber that performs exceptionally well in humid conditions. Thermory Ash has a contemporary pale tone that suits modern interiors and outdoor pavilion designs.

Nordic Spruce

The traditional Scandinavian sauna timber — tight-grained, low-resin, and with a clean white-blonde appearance. Nordic Spruce is an excellent choice for indoor installations in Sydney where humidity is controlled, but requires more maintenance in exposed outdoor positions. Its low thermal conductivity means the walls stay comfortable to touch even at high temperatures.

Abachi

An African hardwood used almost exclusively for sauna benching and backrests. Abachi's exceptionally low density means it absorbs and retains very little heat, staying cool to the touch even in a 90°C sauna. It's the benchmark material for benching in premium custom saunas and is our standard recommendation for all Sydney installations.

Timbers to Avoid

Avoid treated pine, MDF, plywood, and any timber with high resin content (such as standard radiata pine) inside the sauna. At high temperatures, resins can leach out and cause burns, and treated timbers may off-gas chemicals that are harmful in an enclosed space.

Sauna Heaters: Electric, Wood-Fired, and Infrared

The heater is the heart of the sauna. For Sydney residential installations, the three main options are electric, wood-fired, and infrared.

Electric Sauna Heaters

The most practical choice for the vast majority of Sydney homes. Electric heaters are clean, controllable, and compatible with timer and app-based controls. They require a dedicated electrical circuit (typically 15A–20A) but no flue or external ventilation. Premium brands we work with include Harvia, Huum, and Kota — all Finnish-engineered and designed for residential use. Sizing is based on sauna volume: approximately 1kW per cubic metre is the standard rule of thumb, with adjustments for glass panels and outdoor installations.

Wood-Fired Heaters

Wood-fired heaters deliver the most authentic sauna experience — the ritual of building the fire, the smell of burning wood, and the deeply radiant heat from a large rock bed. In Sydney, wood-fired heaters are best suited to outdoor installations with adequate clearance and a compliant flue. Council regulations vary by LGA, so it's worth confirming requirements with your local council before specifying a wood-fired unit.

Infrared Panels

Infrared saunas operate at lower temperatures (45–60°C) and use significantly less electricity than traditional electric heaters. They're a practical option for Sydney apartments or smaller spaces where a full-temperature traditional sauna isn't feasible. Carbon fibre infrared panels are the current standard — they emit a broader spectrum of infrared energy than older ceramic elements and heat more evenly.

Glass and Doors

The door and any glass panels are critical both functionally and aesthetically. All glass used in saunas must be tempered (toughened) to withstand thermal stress — standard float glass is not suitable and is a safety risk.

For Sydney custom saunas, the most popular configurations are:

• Full-glass doors with timber frames — maximise light and create a spa-like feel
• Full-height glass wall panels — ideal for saunas positioned to capture garden or pool views
• Timber doors with a small vision panel — a more traditional look that suits heritage or classic interiors

Doors should always open outward for safety, and handles must be positioned so they can be operated without touching a hot surface.

Accessories and Finishing Supplies

The finishing details elevate a good sauna to a great one. Key accessories for Sydney custom sauna installations include:

• Sauna rocks (kiuas stones): Olivine diabase or peridotite are the standard choices — dense, heat-retentive, and resistant to thermal cracking. Rocks should be replaced every 3–5 years.
• Ladles and buckets: For traditional steam (löyly) — cedar or stainless steel are the most durable options for Sydney's humid environment.
• Thermometer and hygrometer: A combined unit allows you to monitor both temperature and humidity. Bi-metal or glass thermometers are preferred over digital units, which can be damaged by sustained high heat.
• LED lighting: Recessed sauna-rated LED fixtures with dimmer control. Standard household LEDs are not rated for sauna temperatures — use only fixtures specified for sauna use.
• Sauna sand timer: A classic accessory for timing sessions without a phone in the heat.
• Backrests and headrests: Abachi or cedar backrests improve comfort significantly for longer sessions.

Ventilation and Insulation

Two often-overlooked components that significantly affect sauna performance. Proper ventilation — with a low inlet vent near the heater and a high outlet vent on the opposite wall — ensures fresh air circulation and prevents the stale, oxygen-depleted atmosphere that makes a poorly designed sauna uncomfortable.

Insulation behind the timber lining reduces heat-up time and running costs. For Sydney outdoor saunas, we use foil-faced insulation batts with a vapour barrier to manage moisture movement through the wall assembly.

Ready to Source Materials for Your Sydney Sauna?

At Crafted Saunas, we supply and install all materials as part of our custom sauna service — you don't need to source anything separately. Our team will guide you through every material decision during the design consultation, with samples of timber species and heater options available to view in person.

Get in touch to start your Sydney sauna project and let's build something exceptional.