If you've decided to invest in a wood-fired hot tub, you've made an excellent choice — but the difference between a tub that performs flawlessly for a decade and one that causes problems within a year often comes down to preparation. The tub itself is only part of the equation. What sits beneath it and around it matters just as much.
This guide walks you through everything you need to think about before your Bauqua tub arrives: how to choose the right location, what kind of foundation to build, how to manage drainage, and the practical details that most buyers only discover after installation.
A wood-fired hot tub filled with water and occupied by several adults is a serious structure. The Amber 200, for example, holds approximately 1,100 litres of water. Add the weight of the tub itself and two to four adults, and you are placing somewhere between 1,600 and 1,800 kg on a single point of your garden.
That is the equivalent of parking a small car in one spot — permanently, in all weather conditions, through freeze-thaw cycles, rainfall, and summer heat.
A surface that looks solid in summer can shift, crack, or sink over winter. A drain that seems unnecessary on a dry afternoon becomes essential the moment you need to empty 1,100 litres of water. Getting these fundamentals right before installation is far easier and cheaper than correcting them afterwards.
Before you think about foundations, you need to decide exactly where the tub will go. This decision affects everything that follows, so take your time with it.
You need more room than just the footprint of the tub. As a minimum, allow:
For the Amber 225 (225 cm diameter), this means your prepared area should be at least 3.8–4 metres wide and long to feel comfortable in practice. A tight fit might look fine on paper but becomes frustrating when you are carrying firewood or stepping out of the tub on a dark winter evening.
A south-facing spot with some natural wind shelter will reduce your heating time and improve your experience significantly. Wind strips heat from the water surface and makes the space feel less comfortable. A garden wall, timber screen, or dense hedge on the prevailing wind side makes a meaningful difference without creating the enclosed feel of a full shelter.
Avoid positioning the tub directly beneath deciduous trees. Falling leaves, bird droppings, and the sap residue that drips from certain trees will contaminate your water and require constant cleaning. Conifer trees cause particularly stubborn staining on fibreglass surfaces.
Most people want their hot tub close enough to the house to be convenient, but not so close that chimney smoke drifts through open windows. A distance of five to ten metres tends to work well for most gardens. If you are installing electricity for the hydromassage, LED lighting, or antifrost system, you will need a cable run to this point — keep that in mind when choosing the location, as cable runs over ten metres become more complex and costly.
This is the most critical preparation decision you will make. The foundation must be:
There are three foundation types that work reliably. Here's how they compare:
| Foundation Type | Best For | Effort | Estimated Cost |
|---|---|---|---|
| Compacted gravel + stone slabs | Most gardens — versatile, drains naturally | Moderate | €400–€900 |
| Concrete slab | Cold climates, unstable soil, lifetime durability | Higher | €600–€1,400 |
| Engineered timber decking | Aesthetic continuity with existing deck | High (structural engineering required) | Varies widely |
This is the most commonly used and most versatile foundation for a wood-fired hot tub. It is relatively straightforward to construct, performs well in all climates, and the gravel layers handle drainage naturally.
How to build it:
The gravel layers allow water to flow down through the stone rather than pooling around the base of the tub. The slab surface provides a clean, stable, frost-resistant platform.
A poured concrete slab is the most structurally robust option and the best choice if your soil has any history of instability, if you are in a region with very cold winters, or if you simply want a foundation that will never require any future attention.
Specification:
One consideration: a solid concrete slab has no inherent drainage, which means you need to plan where water will go when you drain the tub. See the drainage section below.
A well-built timber deck can work as a hot tub base, and many homeowners prefer the aesthetic continuity it provides. However, it requires considerably more engineering than most people expect.
Structural requirements:
Do not place a full hot tub on an existing domestic deck without first having a structural assessment. Do not use decking boards as the bearing surface directly beneath the tub — the stainless steel feet will concentrate the load onto just a few boards. Build or fit a spreader plate or solid timber pads beneath each support point.
Timber decks also require more maintenance over time and are more susceptible to rot in persistently damp areas. A timber base beneath the tub itself — rather than stainless steel — is one of the leading causes of premature deterioration in cheaper hot tub models. This is precisely why Bauqua uses a stainless steel structural platform: it eliminates this vulnerability entirely.
Drainage is the aspect of hot tub installation that buyers most often overlook, and the one that creates the most problems afterwards. You need to think about two distinct drainage challenges.
A standard Amber 225 holds approximately 1,400 litres of water. If you are using the tub without the antifrost filtration system, you will be changing this water every few days. With the filtration system, you will still drain and refill roughly once a month. Each time, you need somewhere for that water to go.
Your options are:
Treated hot tub water contains chlorine, bromine, or active oxygen residues and can have an altered pH. It is not suitable for vegetable gardens, sensitive ornamental plants (rhododendrons, blueberries, azaleas), watercourses, or ponds.
Allow chemicals to dissipate for 24–48 hours after final treatment before draining to a lawn, or use a soakaway pit for any water that was recently chemically treated. Never drain large volumes of chemically treated water into a confined area with no outlet.
The area around a hot tub gets wet constantly — from people climbing in and out, from the tub being filled, from rain, and from the steam that condenses on surrounding surfaces. If this water has nowhere to go, it will pool, freeze in winter, and over time damage your foundation surface.
Build a slight fall (1–2%) away from the tub on all sides when constructing your foundation. If you are using a gravel-and-slab approach, the gaps between slabs allow water to drain naturally. If you are pouring concrete, include a drainage channel or gully at the low edge of the slab.
This is a practical detail that causes genuine problems if it is not considered in advance. Hot tubs are large, heavy items — the Amber 225 arrives in packaging that requires a clear, firm path from the delivery vehicle to the installation point.
Before your delivery date:
The wood-fired heating system operates entirely without electricity. However, if you plan to use the hydromassage, LED lighting, or the antifrost and filtration system — all of which are highly recommended — you will need a 230V single-phase supply with a 16A fuse run to the tub location.
This work must be carried out by a qualified electrician. The installation should include:
Have your electrician complete the installation before the tub arrives so you can connect and test all functions on the day of delivery.
At Bauqua, we speak to a lot of customers who have replaced an older or cheaper hot tub. In almost every case, the problems they experienced — whether a rotting base, a cracked slab, persistent water pooling, or a tub that sat slightly unlevel and developed leaks — came from preparation shortcuts taken at the start.
The hot tub itself is built to last. But no tub — regardless of how well it's built — performs well on a poor foundation. Take the preparation seriously, do it once, and do it properly.
Have questions? Talk to our team →Everything you need to confirm before your hot tub arrives.
A hot tub holds 1,200–1,600 L of water.
Only required if using hydromassage, LED, or filtration.
The hot tub itself arrives ready. What you do in the weeks before it gets there determines whether it performs the way it should, or causes problems within months.
Take the preparation seriously, do it once, and do it properly. The reward is a hot tub that works flawlessly every time you use it — for years to come.
Our Amber series is engineered for long-term outdoor use. Free EU shipping, 2-year warranty, and direct support from the team that built your tub.
Tell us about your plans and we will prepare a personalised recommendation.
We typically respond within 24 hours.
Tell us about your plans and we will prepare a personalised recommendation.
We typically respond within 24 hours.
