Do Outdoor Saunas Need Covering?

Dec 27, 2025

Rainy afternoons, surprise frosts, and blazing summer sun can all gang up on Outdoor Saunas. So, do outdoor saunas need covering? Short answer: yes, in most cases. Covers protect against weather damage, reduce maintenance, and improve efficiency. Keep reading to see when, why, and how covering really pays off.

Permanent Roofing and Structural Protection

Permanent roofing provides the most reliable protection for outdoor saunas. Without it, even high-quality timber structures can deteriorate much faster than expected. A solid roof shields the sauna from constant moisture exposure.

It also helps maintain internal temperatures and structural integrity.

Why a Waterproof Roof System is Non-Negotiable

The roof takes the full force of British weather.Rain, temperature changes, and winter frost all hit from above. A properly waterproofed roof prevents water ingress.
It protects insulation and reduces long-term repair costs.

Compact wooden sauna pod with curved roof and double glass doors on lawn.

Bitumen Shingles: The Industry Standard for Barrel and Cabin Saunas

Bitumen shingles are widely used on barrel and cabin saunas. They are flexible, durable, and well suited to UK conditions. They shed rain effectively and handle temperature changes well.

This makes them a practical and proven roofing option.

EPDM Rubber Roofing: Maximum Longevity for Flat-Roof Modern Saunas

Flat-roof saunas benefit greatly from EPDM rubber roofing. This material offers excellent waterproofing and a long service life. It requires minimal maintenance once installed.
For modern sauna designs, it is one of the most reliable options available.

The Risk of "Raw" Wood: Why Untreated Roof Boards Fail Within 2 Years

Untreated wooden roof boards absorb moisture quickly. This leads to swelling, cracking, and eventual rot. In many cases, failure occurs within two years.
Without a waterproof layer, even durable timber will degrade prematurely.

External Timber Treatments vs. Physical Covers

Roofing protects from above, but walls and staves still face weather exposure. This is where timber treatments and coatings play an important role. Both approaches help, but they serve different purposes.

Neither should fully replace proper ventilation.

UV Protection: Using Wood Stains to Prevent Silvering and Brittle Fibres

UV exposure causes timber to silver over time. It can also make fibres brittle and weaker. UV-resistant stains slow this process significantly. They help preserve both appearance and strength.

Hydrophobic Coatings: Helping Rainwater Bead Off the Staves

Water-repellent coatings reduce moisture absorption. Rain beads and runs off rather than soaking into the wood. This shortens drying time after wet weather.

It also reduces long-term timber stress.

The "Breathability" Rule: Why You Should Never Wrap a Sauna in Plastic

Wrapping a sauna in plastic traps moisture. This creates ideal conditions for mould and internal rot. Any protection used must allow airflow. Moisture needs a way to escape naturally.

Shelters, Gazebos, and Seasonal Storage Covers

Beyond roofing, additional structures can offer extra protection. Shelters and covers are especially useful in exposed gardens. The right option depends on how often the sauna is used. It also depends on local weather conditions.

Light wooden outdoor sauna pod with glass door on garden decking.

Building a Permanent Shelter or Gazebo for Your Sauna

A shelter or gazebo adds a second line of defense. It protects against rain, snow, and strong winds. This is particularly helpful in open or coastal locations.

It also improves year-round usability.

The Benefits of a Secondary Roof: Reducing Maintenance and Heat Loss

A secondary roof reduces direct weather exposure. This lowers maintenance demands on the sauna exterior. It also improves heat retention during use.
That can reduce warm-up time and energy loss.

Ensuring Proper Airflow: Why Overhangs Must Not Block Ventilation Vents

Shelter design must allow proper airflow. Roof overhangs should never block ventilation vents. Ventilation is essential for safety and moisture control.
Blocked airflow can lead to internal damp issues.

Creating a Dry Entry Zone: Enhancing the "Winter Dash" Experience

A sheltered entrance keeps towels and footwear dry. It also makes winter sauna use far more comfortable. This small detail greatly improves the overall experience.
Especially during cold or wet weather.

Using Temporary Storage Covers During the Off-Season

Temporary covers are useful when saunas are unused for long periods. They are particularly helpful during winter or extended travel. The key is choosing the right type of cover.

Breathability is essential.

Outdoor wooden barrel sauna on raised deck beside modern house and garden.

When to Use a Breathable Fabric Cover for Barrel Saunas

Breathable fabric covers work well for barrel saunas.They protect from rain while allowing moisture to escape. This makes them suitable for off-season storage.
They should still be checked regularly.

The Danger of Trapped Moisture: How Tight Covers Cause Internal Mould

Tight, non-breathable covers trap condensation. This can lead to mould and mildew inside the sauna. In some cases, damage is worse than leaving it uncovered.
Moisture control should always be the priority.

Protecting the Hardware: Covering the Wood-Stove Flue and Heater Vents

Metal components need protection too. Rain exposure can cause corrosion over time. Covers should shield flues and vents without sealing them completely.

Airflow must remain unobstructed.