Redwood Outdoors Review: What It’s Like to Build a Sauna Kit in My Backyard

I’ve long dreamt of having an outdoor sauna just steps away from my backdoor. With a three-season outdoor shower already in place and nearly a half-acre of land to work with, my home by the sea in coastal Maine was practically begging for one. And, after the many hours spent (happily) researching and writing about outdoor saunas (and wood fired hot tubs and cold plunges) here at Field Mag, my interest was piqued. Despite my apprehensions about building one myself, I decided to take a shot on a new outdoor sauna kit from retailer Redwood Outdoors. Spoiler: it was way easier than I thought.

In this article, I’ll share exactly what it’s like to buy and build a sauna kit with minimal building experience while breaking down each step along the way to your personal sauna heaven including: choosing a kit versus prefab, the sauna model (i.e. sauna shape, type of heater like the Harvia electric sauna heater, and features such as seating capacity) and where to order from.

My hope for this review of the Redwood Outdoors Mini-Cube Sauna kit is to share the kind of valuable firsthand experience that helps others feel confident and capable enough to buy and build their own personal outdoor sauna.

Choosing the Right Sauna for You

The Redwood Outdoors Mini-Cube 2-Person Sauna is a compact, cube-shaped traditional sauna made from Scandinavian Thermowood, a process that treats different wood species with high heat and steam to create a durable, rot-resistant, well-insulated material made to last a lifetime (other common woods used in sauna kits include Nordic spruce and clear western red cedar). The small size measures about 5 ½ feet long, 4 feet wide, and 6 ½ feet high, which helps make the most of your outdoor space without sacrificing a comfortable yet cozy interior. (For larger groups I suggest an outdoor barrel sauna or cabin sauna.)

Thermowood construction is particularly notable for its resilience and eco-friendliness, and it pairs beautifully with the Harvia sauna heater, a renowned choice among sauna enthusiasts. The mini-cube design, while compact, offers an immersive sauna experience similar to a traditional Finnish sauna, especially when paired with authentic sauna stones.

Site Prep and What to Know Before Your Sauna Kit Arrives

Due to my sauna’s compact size, minimal site prep was required. After we chose the perfect spot nestled among some pines, we dug out a 54-inch long by 72-inch wide area in the grass and buried four concrete deck footers purchased at my local hardware store in each corner. For the base, we built a wooden platform with pressure-treated lumber to save time and money on a level, sturdy foundation instead of pouring a concrete pad like Redwood Outdoors suggests. Lastly, we filled in the open space with weed cover and pea gravel for drainage.

To complete site prep we needed to dig a roughly 30-foot-long, one-foot-deep trench from our house to bury the electric cable that would connect our sauna to the power grid. We could have paid the electrician to do this, but opted to DIY instead to save money.

For those considering a different type of sauna, like a thermowood barrel sauna, the process may vary slightly, especially in terms of base and site preparation. Barrel saunas, often lauded as the best barrel saunas for their aesthetic and efficient design, may require a more specific base due to their unique shape.

We contacted the licensed electrician far enough in advance to get a quote and schedule the installation during the week of the build so we could use it right away. Redwood Outdoors has the assembly manual for the sauna and heater on their website to help you and any hired professionals prep. All that was left was to make sure we had all the tools necessary (Philips screwdriver, 7/16” and 9/16” open end wrenches, 9/16” deep socket wrench, vise grips, and a mallet), and it was build time.

Sauna Kit Delivery: What to Know

When purchasing from Redwood Outdoors, the unassembled sauna kit and heater may be delivered in separate shipments. The Harvia heater and sauna rocks ship through FedEx just like any other package; however, the sauna materials and additional components were delivered via FedEx Freight in a wooden shipping crate on a scheduled delivery date.

Be sure to keep an eye on your email for tracking updates as FedEx requires a scheduled delivery with a signature. Redwood Outdoors did a great job of sending automated emails when the items shipped to help me keep track of everything.

What’s Included in a Redwood Outdoors Mini-Cube Outdoor Sauna Kit?

All pieces of the precut sauna kit arrive neatly stacked and well organized inside a single wooden crate. Cracking open the top released a heavenly wood smell that makes it all feel very real and exciting.

Inside you’ll find the materials that compose the main structure of the mini-cube sauna, which, similar to a barrel sauna, includes the front wall with glass door already installed, a back wall, and about 50 wooden staves that fit together to form the side walls and roof; plus two cradles for the base.

My kit included:
- Two stainless steel bands that wrap around finished sauna
- One interior bench, back rest, and footrest
- One wooden front step
- One interior LED light
- Sauna thermometer and hygrometer
- Roof shingles
- Sauna bucket and ladle
- One door mat
- Felt sauna hat for temperature regulation (and fashion!)
- All screws and hardware, numbered and labeled for assembly
- A step-by-step instruction manual

Some of the items we received were add-ons, such as the shingles and wooden step. For the full at-home wellness experience, dive into the world of sauna accessories—and try pairing your sauna with a cold plunge tub.

Building Your Sauna Kit

How long does it take to build a DIY sauna kit? Two people with basic building experience should be able to assemble a sauna kit in half a day using a handful of common tools most people already own. For our build, we used three levels (a four-foot, two-foot, and 9-inch level), two cordless drills (one for each of us), a soft mallet for setting the staves, an adjustable socket wrench, and a couple of measuring tapes.

With my sauna kit build experience in mind, I would recommend doing before you begin on your project:

1. Read the paper manual delivered with the sauna all the way through and pull up the assembly video on the product page—there were moments when a visual example really helped. Redwood Outdoors also has great customer service, which was useful when we had a question about the Harvia electric heater and resolved things within fifteen minutes!

2. Check the weather forecast (we got skunked by a surprise afternoon rain shower on day one, it is New England) and give yourself enough time to complete the build before it gets dark.

3. Stay organized! The wood pieces are numbered with removable stickers, but the hardware comes in individual bags, and it’s very easy to mix up the screws because some look similar. Be diligent and don’t remove any labels throughout the sauna build process to save yourself a lot of time and a few gray hairs.

Overall, the manual very clearly guides you through the process from the ground up. Assembling the body was easy and enjoyable because it mainly involves screwing in staves. The most complicated part, relatively speaking, was installing the interior finishings like the wooden heater guard and bench, because they required leveling and measuring, yet was still very simple.

One final and important detail to note is the roof shingles. Unless your sauna is under a deck or covered by something else, you do need protection from rain and snow. Instead of using the shingles, we chose to build a metal roof overtop to match the aforementioned chicken coop (we like cohesive designs, ok?) to keep the elements out. During the interim, when the sauna was exposed, rain would leak through and get the sauna wet, which is not a great experience. The wood won’t rot, but it can get musty if you leave it wet and unused for too long.

Hooking Up the Electric Heater and Light

I highly recommend hiring a licensed electrician to connect the light and heater. Our electrician took a full day to complete this portion of the project, which included installing a disconnect switch on the exterior of our house as a safety precaution.

Digging the trench ourselves helped save money here, but the electric hookup still cost an additional $1,700. Since this isn’t included in the price of the sauna kit, it’s important to factor that into your total cost. It's also worth noting the cost of labor may be lower or higher where you live.

If you're considering a different setup, like a Harvia electric sauna heater paired with an indoor sauna or an infrared sauna with wi fi heater, these factors might change slightly.

Using the Redwood Outdoors Mini-Cube Sauna

There is truly nothing more satisfying than enjoying your first sweat after building a sauna with your own two (well, technically four) hands. Before you use it, Redwood Outdoors recommends “breaking it in” by rinsing off the sauna rocks, cranking the heat up to the highest temperature for one hour to cure the wood and burn away any impurities, and then slowly pouring a liter of water over the rocks.

Using the sauna is easy, and because it’s such a small space, it heats up to 160-170 degrees Fahrenheit in about 40 minutes. The Harvia heater has two dials on the bottom: a temperature and a timer. The timer can be set for a one or eight-hour delay, so you can set your heater to turn on when you’re ready to use it.

Initially, I was skeptical about the sauna comfortably fitting two people on the bench. At best, I thought it would be, er, snug, but we were pleasantly surprised at how much space there is for two people. That being said, it is quite nice to relax in the warmth and solitude of the mini-cube sauna solo.

For those with more space or who want to entertain, a larger model like a 6 person barrel sauna or a thermowood panorama sauna might be a better fit. These models often feature enhanced seating capacity and more powerful heaters that can reach up to 195 degrees, offering a true Finnish sauna experience.

Final Thoughts

With a base price of $5,399, Redwood Outdoors' most compact outdoor sauna is an investment for sure, but for the quality, ease of delivery and assembly, and many years of use ahead, it's a great value for anyone who wants their own backyard oasis.

Hopefully this review has been helpful, especially if you’re considering different options from competitors like the Plunge Sauna, Sun Home or Forest Cooperage (the former offering premium Canadian made cedar saunas, cold plunge tubs, and hot tubs). Whichever route you take, your dream sauna experience is close at hand.

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