Leil Celto M Outdoor Sauna

1. Heater Package - Select "Bring Your Own Heater" if you're sourcing separately, or choose a complete factory package that includes Heater + Sauna Stones + Control unit. We stock complete bundles from three of the top sauna-heater manufacturers in the world: Harvia (Finland), Homecraft (Estonia), and HUUM (Estonia). Bundle-pricing your heater at checkout saves 5-10% versus buying the same components separately.
2. Lighting - Choose "No Lighting" for a fully unlit kit, or add Backrest and Under Bench Lighting - LED-strip lighting for under the bench and behind the backrest, controlled by a dimmer switch. Kit includes LED strip, cable, transformer, dimmer switch, and installation box. Sized specifically for each Celto model.

Want a custom stained look? Every Celto ships in natural unstained spruce so you can finish it on-site with any exterior wood stain from your local hardware store - see the "Make It Yours" section above for details.

Foundation & Electrical Requirements

Foundation Requirements

The Celto requires a level, non-shifting foundation. Any of the following work:

• Poured concrete pad, 4 in. minimum thickness, sized ~4 in. larger than the sauna footprint on all sides
• Compacted gravel pad topped with concrete pavers
• Existing reinforced deck rated for the sauna's weight (approximately 700 lbs for the Celto S / 1,000 lbs for the Celto M, plus 2-4 users)
• Level, undisturbed soil is not sufficient - the sauna needs a rigid, drainage-friendly surface underneath

Assembly Overview

The Celto is designed for follow-the-numbers modular assembly. The kit ships flat-packed with every panel, board, and fastener pre-cut and numbered to match the illustrated 20-step manual. Two adults can complete the Celto S in one long day, or the Celto M in one to two days with three people for the glass panel installation.

Assembly Sequence (Overview)

1. Site prep - level the foundation, position the base runners
2. Frame the floor panel (F1 + F2 base with structural brackets)
3. Erect wall panels (W60 side wall + W80 back walls with W290 rear support)
4. Install ventilation ports (intake V200 at 200 mm from panel edge, exhaust V400 at 400 mm)
5. Set ceiling panels and interior cladding
6. Install door frame with S80 screws + door with matte black hardware
7. Set tempered glass side panels with aluminum retaining slats
8. Install benches, backrests, and (if included) LED strip channel
9. Lay EPDM roof membrane
10. Mount and wire heater; install thermostat sensor per heater manual

All required nails and screws are counted and included. Only recommended tools: a cordless drill/driver with Ø 3 mm and Ø 4 mm pilot bits, a level, and rubber-soled work gloves.

Warranty & Care

Structural Warranty: 24 months on the Celto cabin structure, hardware, and factory workmanship, honored by the Estonian manufacturer through Midwest Nordic. Damage from improper assembly (contrary to the printed manual) or unauthorized modifications voids the warranty.

Heater Warranty: Each heater in the Heater Package options carries its own manufacturer warranty - Harvia (2 years), Homecraft (2 years), HUUM (5 years on the Drop and Hive Mini heaters, 2 years on UKU controllers).

Exterior Wood Care: Every Celto ships in natural unstained spruce. Left untreated, the exterior will silver over time from UV exposure - a signature "Nordic weathered" look many customers love. To preserve the fresh tone or achieve a specific color, apply an exterior wood stain (Behr, Cabot, Sherwin-Williams, Sikkens, Olympic - any quality hardware-store brand) within the first few weeks of assembly. Reapply per the stain manufacturer's recommended interval (typically every 2-4 years). Clean with a soft brush and mild soap; avoid close-range pressure washing.

Interior Wood Care: The interior spruce, aspen benches, and backrests do not need any coating (coatings would crack under sauna heat). Sweep out ash / stone dust after each use; wipe down benches with a damp cloth. Every 6-12 months, treat the benches with sauna-safe paraffin oil to preserve grain and moisture resistance.

Celto Frequently Asked Questions

What is a Celto sauna and how is it different from Leil?
The Celto series is manufactured by Saunasell OÜ, a subsidiary of Leil Saunas OÜ in Estonia. Where Leil's Patio / Dice / Round Cube lines target the premium, architectural end of prefab sauna design, the Celto series is engineered as the accessible entry point into premium outdoor sauna ownership - the same Estonian manufacturing pedigree, a curated two-size lineup (S and M), and a simpler configuration decision, at a lower MAP price than the equivalent Leil model. Celto is available exclusively through Midwest Nordic in North America.

Is the heater included?
No - like most premium prefab saunas, Celto ships as a cabin kit and heater is selected separately. That said, we've made it easy: choose a complete Heater Package from the dropdown on this page and we'll ship the heater, sauna stones, and control unit factory-bundled with the sauna kit. If you already have a heater, or if you want to source one on your own, select "Bring Your Own Heater" and the kit ships without the heater.

What heater size do I need?
Celto S: 4.5-6 kW is ideal. Celto M: 6-9 kW is ideal. The bundled Heater Package options on this page are sized to match - pick any option in the dropdown and you'll get correct output.

How is Celto sized for occupancy?
The Celto S is a 1-2 person sauna with a single bench and a removable bench box (which doubles as a changing seat). The Celto M is a 3-4 person sauna with two-tier benching and a front-room bench box.

Can I install a Celto indoors?
Celto is engineered as an outdoor sauna - the EPDM roof, exterior wall coatings, and ventilation are all sized for outdoor use. It's possible to install indoors in a large space (garage, basement) as long as you provide equivalent ventilation and manage the heater's steam/humidity output through the room's HVAC - but our recommendation is to install Celto outdoors as designed.

Can I use the Celto year-round?
Yes. The Celto is engineered for four-season outdoor use in every US climate zone, from South Florida humidity to Minnesota winters. EPDM roof, 60 mm insulated panels, tempered glass, and marine-grade fasteners are all rated for freeze-thaw cycling.

What foundation do I need?
A level, rigid, non-shifting foundation is required. A concrete pad, gravel pad with pavers, or a reinforced deck rated for the sauna's weight will all work. Bare compacted soil is not sufficient.

How long does assembly take?
Celto S: 6-8 hours with two adults. Celto M: 1-2 days with 2-3 people (you want a third person to safely lift the glass panels into place). The kit ships flat-packed with pre-numbered panels and a step-by-step illustrated manual.30 A for 4.5-6 kW heaters, 40 A for 8-9 kW heaters. Harvia KIP B uses an integrated dial (no external control needed). Harvia KIP W ships with the Xenio WiFi smart control; Harvia Virta uses a separate Xenio WiFi wall control mounted just outside the sauna. Homecraft heaters ship with the TKE2-2 WiFi controller. HUUM Drop and Hive Mini include the UKU WiFi controller as part of the package.

Why does Celto use spruce instead of cedar?
Nordic spruce is the traditional wood for Finnish and Estonian saunas - it has lower resin release at high heat than cedar (so it won't drip or over-scent), a lighter and cleaner grain, and better dimensional stability across freeze-thaw cycles. The interior benches and backrests are Aspen (or optionally Alder), both of which are exceptionally low-thermal-conductivity - cool to the touch even at 200°F.

Does the Celto come pre-stained in a color?
No - every Celto ships in natural unstained Nordic spruce. The sample photos you see throughout this listing (whitewash, beige, anthracite charcoal, etc.) are examples of finishes customers have achieved by applying an exterior wood stain from a hardware store after assembly. This gives you complete freedom to match the sauna to your specific landscape, deck, or home exterior - and there's no color upcharge because you pick and buy the stain locally. Any quality exterior wood stain (Behr, Cabot, Sherwin-Williams, Sikkens, Olympic) works.

Can I leave the Celto in natural wood without staining?
Absolutely. Untreated Nordic spruce will silver over time from UV exposure - a signature "Nordic weathered" look many customers love. If you want to preserve the fresh tone, apply a clear UV-protective wood oil in the first year. Either path is fine - this is a design choice.

Is the Backrest and Under Bench Lighting worth it?
The factory lighting kit delivers accent LED illumination behind the backrest and under the bench - a warm, dimmable glow, not a bright overhead light. Most customers who add it never wish they hadn't; a few who skip it install a hardware-store LED strip later. The factory kit is specifically engineered for sauna heat and humidity; generic DIY LED strips are often not heat-rated for a sauna environment.

What's the warranty?
24 months on the Celto structure and hardware from Midwest Nordic. Each heater carries its own manufacturer warranty (Harvia 2 years, Homecraft 2 years, HUUM 2-5 years depending on component). Painted exterior finishes are backed by our finish warranty against premature checking / peeling in normal residential outdoor use.

How is shipping handled?
Celto ships freight LTL from our warehouse. Delivery is curbside (the driver drops the crated kit at your driveway or garage entry) - you'll want two people ready to move the crates to the assembly site. Contact us for a shipping quote based on your zip code before placing the order.

Can I order additional bench sections, LED, or replacement parts later?
Yes. Every Celto part in the manual has a part code; we stock replacement panels, benches, glass, and hardware. Contact Midwest Nordic customer service with your model and the part code.

The Full Leil Celto Line

• Leil Celto S - 1-2 person compact outdoor sauna. Base MAP $4,990. Ideal for smaller yards, condos with private outdoor space, or as a companion to a hot tub / cold plunge.
• Leil Celto M - 3-4 person outdoor sauna with two-tier benches and front-room bench box. Base MAP $5,990. Our most popular Celto configuration for family and couples' use.

Also from Leil Saunas

Explore the full Leil family: Patio series (7 sizes, XXS through L Plus), Dice series (5 modern geometric layouts), and Round Cube series (4 cylindrical premium models).

The Leil Celto series is sold exclusively through Midwest Nordic in North America - not available at any other US reseller.

Base MAP shown reflects the sauna cabin kit only. Final invoice reflects your selected heater package, finish, and lighting add-ons. Contact Midwest Nordic for shipping quote and delivery scheduling.