Building an outdoor sauna can be a fun and rewarding project. With the right planning and materials, you can create a peaceful oasis right in your own backyard. In this comprehensive guide, we will walk you through the entire process of constructing an outdoor sauna from start to finish.
Choosing a Location
The first step is deciding where to build your sauna. Here are some things to consider when picking a location:
- Convenience – Choose a spot that is easily accessible from your home or deck. You don’t want to have to trek across the yard every time you want to use it.
- Privacy – Pick a secluded area of your yard where the sauna can be a private retreat. Consider adding visual barriers like trees or fencing if needed.
- Sun exposure – Full sun is ideal but dappled shade can work too. Avoid heavily shaded areas.
- Proximity – Don’t locate the sauna right next to a neighbor’s house or other buildings. Leave ample space on all sides.
- Utilities – If you plan to have electricity and plumbing in your sauna, situate it close to the home for easier hookups.
- Views – Position the sauna to take advantage of nice scenery from mountains to gardens.
- Drainage – Choose a level spot with good drainage to prevent flooding issues. Avoid low lying areas.
Once you’ve selected the perfect site, mark it off and start planning the foundation.
Constructing the Foundation
A proper foundation is crucial for structural integrity and preventing settling. Here’s how to build one:
- Size – The foundation should extend beyond the perimeter of the sauna by 6-12 inches.
- Material – Concrete makes the best base. Gravel and stone dust are other options.
- Depth – Dig down at least 12 inches for the footing. Deeper is better in colder climates.
- Frame – Construct a wood frame around the perimeter using treated lumber.
- Rebar – For added strength, include rebar or a wire mesh grid before pouring concrete.
- Drainage – Create a slight slope to assist with drainage. Installing a french drain is also an option.
- Curing – Allow concrete to fully cure for 5-7 days before building on top.
Taking the time to construct a solid foundation will provide long-lasting support for your sauna structure.
Framing the Walls and Roof
With the foundation in place, it’s time to frame up the basic structure. Here are the key steps:
- Size – Standard dimensions are 4×6 feet up to 8×10 feet. The size depends on your space and budget.
- Materials – Use moisture resistant wood like cedar, redwood, or treated pine. Avoid non-resistant woods.
- Corner Posts – Secure 6×6 inch posts vertically at all corners to anchor the walls.
- Wall Framing – Attach 2×4 or 2×6 beams horizontally between the corner posts and vertically every 16 inches.
- Door Opening – Create a door frame with double headers and trimmer studs. Standard width is 24-36 inches.
- Roof Framing – Build A-frame style trusses, rafters, and headers to desired pitch and height.
- Sheathing – Cover the roof and walls with 1/2 inch plywood sheathing. Leave openings for door and ventilation.
- Moisture Barrier – Line the inside with tar paper or house wrap.
Take measurements carefully and use heavy duty galvanized fasteners like lag bolts. Check local building codes for any requirements.
Adding Insulation
Insulation is what allows the sauna to retain heat. Here are some key insulation installation tips:
- Walls – Use R13 to R19 fiberglass batts or rigid foam boards. Keep vapor barriers on the warm side.
- Ceiling – Use R30 to R40 insulation between the rafters. Add a vapor barrier.
- Floor – Under the foundation, place 2-4 inches of rigid foam board insulation.
- Sealant – Caulk around windows, doors, and all seams to minimize air leaks.
- Vapor Barriers – Install barriers like Tyvek house wrap under the siding with seams taped.
- Ventilation – Leave air gaps at the top and bottom of the walls for airflow.
Proper insulation will greatly improve the heating efficiency of your sauna. Perform this step carefully to maximize performance.
Installing the Sauna Heater
The sauna heater unit is the essential heating element. Follow these guidelines for installation:
- Type – Choose an electrical heater designed for saunas rated 4.5-9kw depending on size.
- Placement – Position the heater low on the wall opposite the door around knee height.
- Mounting – Attach to the wall securely following all manufacturer instructions.
- Wiring – Hire an electrician to connect wiring and install a dedicated breaker.
- Safety – Place protective railing or fence around the heater if needed.
- Testing – Turn on the heater and verify functionality before finishing the walls.
Select a high-quality sauna stove and have it installed properly for safety. This will be the “heart” of your sauna providing dry heat.
Finishing the Exterior
Now you can complete the outside structure:
- Siding – Use tongue and groove pine, cedar boards, or pine panel siding.
- Roofing – Cedar shakes or asphalt shingles are good options.
- Door – Choose an insulated wooden sauna door with windproofing. Install securely.
- Hardware – Add handles, pulls, hinges, and any exterior lighting.
- Paint/Stain – Use exterior grade finishes. Dark muted tones work well.
- Sitting Bench – Build an outdoor bench area if desired.
Focus on weather resistance and aesthetics for the exterior surfaces. This protects the sauna and makes it more enjoyable to use.
Creating the Interior Details
The relaxing sauna interior comes next:
- Wooden Benches – Arrange lightweight cedar benches around the perimeter. Use different heights.
- Back Rests – Affix cedar boards to the walls for comfortable reclining.
- Flooring – Use heat-resistant tile, concrete, or granite cobblestones.
- Ceiling – Tongue and groove pine boards make an attractive ceiling.
- Lighting – Install waterproof lighting and sconces on dimmer switches.
- Rocks – Place smoothed igneous rocks around the heater to hold heat.
- Thermometer/Hygrometer – Mount them at eye level to monitor temperature and humidity.
- Storage – Add wooden racks, buckets, ladles, and thermometers as needed.
The interior finishing provides ambiance. Focus on natural materials and a simple, uncluttered design for relaxation.
Heating System and Maintenance
Follow these tips once your sauna is built:
- Heat Time – Preheat for 30-60 minutes to reach desired temperatures.
- Heating Elements – Arrange rocks around elements and replace them annually.
- Ventilation – Leave vents open when not in use to allow airflow and reduce moisture.
- Hygiene – Wash benches, walls, floor with disinfectants regularly.
- Door and Seals – Check the door and seals occasionally for air leaks. Realign if needed.
- Interior Wood – Scrub siding with wood soap and re-oil occasionally.
- Safety – Always monitor the heater when in use. Install warning signs.
- Electric and Plumbing – Have an electrician and plumber inspect annually.
Performing routine sauna maintenance will keep it safe and relaxing for years of enjoyment.
Frequently Asked Questions
How much will it cost to build an outdoor sauna?
The total cost depends on size, materials, and components chosen. Budget $4000-$8000 on average for a basic 6×6 foot sauna up to $15,000 for a more lavish 8×10 foot one with high-end fixtures.
What size outdoor sauna is best?
The standard recommendation is at least 6 feet x 6 feet for 1-2 people. A 6×8 or 8×8 sauna provides additional space for 4-6 people to use comfortably.
Should my outdoor sauna have electricity and plumbing?
It’s recommended to install electricity to power the sauna heater and lights. Plumbing is optional for running water, but most outdoor saunas function fine without it.
What is the best material for sauna benches?
Western red cedar is ideal for sauna benches because it is lightweight, naturally resistant to decay, and has a smooth finish that won’t split. Avoid using pine which can warp.
How hot does an outdoor sauna get?
Saunas are generally heated to 170-190 degrees Fahrenheit at head level with lower temperatures at the floor around 120-150F. The ideal range for safety and comfort is 160-185F.
Conclusion
Constructing an outdoor sauna is a big project but well worth the investment. Following the planning and building steps outlined above will help you create a top-quality sauna customized to your space and needs. Locate your new sauna in a secluded spot, use moisture-resistant materials, install proper insulation, and add high-quality fixtures. Your backyard sauna will then provide an oasis for relaxation and rejuvenation for years to come.