Wood-Fired Hot Tubs
Aiste Grand.Six seats, one fire, zero fuss.
Our best-selling wood-clad hot tub, thermowood shell, integrated wood-fired stove, six-person soak in under 90 minutes.
Overview
Aiste Grand Hot Tub.
The Aiste Grand is the hot tub we install more of than any other, a 2m diameter thermowood soaking tub that comfortably seats six adults and heats from cold to 38°C in around 90 minutes on a single stove-load of dry hardwood.
Everything about it is built for Scottish weather. The shell is thermally-modified spruce, the internal liner is glass-fibre reinforced polypropylene, and the stove is a submerged marine-grade stainless unit that pulls water through a natural convection loop, no pumps, no electricity to run it, no annual boiler service.
It ships as one piece, lands on prepared slabs, and is ready to fill within an hour of the crane leaving. That's why couples, growing families and short-let hosts across Central Scotland end up choosing this one over an acrylic spa.
Key features
What makes it different.
Genuine 6-adult capacity
2.0m internal diameter with a moulded bench, six adults sit shoulder-square without knees touching.
Wood-fired, no running cost
Integrated marine-grade stainless stove. Around £2 of hardwood per session. No standing electricity draw.
90-minute heat-up
From 8°C cold-fill to 38°C in roughly 90 minutes with dry ash or beech at ~4kg/hr.
Thermowood outer shell
Kiln-modified spruce, stable, rot-resistant, silvers gracefully. Not painted stain that peels off in year three.
Insulated lid included
Two-piece insulated lid keeps heat overnight for a same-day reheat in 20 minutes.
10-year shell warranty
Structural warranty on the shell, 2 years on the stove, lifetime local support from our Falkirk workshop.
Specification
The numbers behind the object.
- Capacity
- 6 adults
- External diameter
- 2.15 m
- Internal diameter
- 2.00 m
- Water depth
- 0.90 m
- Water volume
- ≈ 1,600 litres
- Heat-up time
- ≈ 90 minutes
- Shell
- Thermowood spruce, 40mm
- Liner
- GRP polypropylene, food-grade
- Stove
- Marine-grade stainless, submerged
- Weight (empty)
- ≈ 320 kg
- Warranty
- 10 yr shell · 2 yr stove
Living with it
How it actually works day to day.
You don't chlorinate a wood-fired tub the way you would an acrylic spa. Most owners run a light hydrogen-peroxide dose and drain/refill every two to three weeks, takes an hour, costs pennies, and the water is markedly softer on skin than any chemical spa we've been in.
The stove eats surprisingly little wood. A typical family soak, heat from cold, three-hour session, one reheat, burns 8–12kg. That's a single kiln-dried netted bag from any Scottish forecourt for around £6. Compare that to an acrylic spa averaging £45–£90 a month in electricity through a Falkirk winter.
Maintenance is minimal. Sweep the flue once a year, keep the stove ash-tray clean, and reoil the outer thermowood every 2–3 seasons if you want to keep the honey tone (or leave it and let it silver). No pumps to replace, no ozonator boards to fail, no control unit to reboot.
Best for
Who typically buys this one.
- Families of 4–6 who want one tub that fits everyone
- Rural properties without a hardwired outdoor spa circuit
- Short-let / Airbnb hosts wanting a low-running-cost trophy amenity
- Owners who value the ritual of the fire as much as the soak
On-site footage
See it in motion.
Still images only tell you so much. These short clips show the Aiste Grand Hot Tub exactly as it sits in a finished garden, the details a spec sheet can't convey.
Aiste Grand as a cold plunge
See the Aiste Grand set up for cold-water immersion, the same thermowood shell most owners use as a heated tub, filled cold for a post-sauna plunge. Notice how quickly it fills, how stable the shell sits on the base, and how the timber weathers naturally after a season outdoors in Central Scotland.
Real installations
Aiste Grand Hot Tub in Scottish gardens.
Every photograph on this page is a genuine Signature Garden Rooms installation.
Around 90 minutes from a cold fill of ~8°C mains water to a soaking temperature of 38°C, using approximately 8kg of dry hardwood. A same-day reheat under the insulated lid takes 15–25 minutes.
Next step
Ready to talk about the Aiste Grand Hot Tub?
Tell us your garden, your access, and roughly when you'd like it in. We'll come back with a considered price, honest lead time, and any planning notes for your site.
Fully insured · £5m public liability · Falkirk-based, working across Central Scotland