Hot tub on decking – how to choose and prepare the space

Hot tub on decking usually means choosing between a round wood fired hot tub, a round garden hot tub with hydromassage and a square garden hot tub. Before buying, you need to check three things: whether the terrace can support a filled hot tub with people inside, what power supply is available, and where the heater or control panel will be placed.

How much does a garden hot tub on a terrace weigh?

A filled garden hot tub weighs from approx. 960 kg (SIMPLE 160 cm: 160 kg + 800 l of water) to approx. 1 450 kg (220-220 garden hot tub: 350 kg + 1 100 l), plus the weight of the users. Per 1 m² of the terrace this is from approx. 300 kg (square tubs) to approx. 480 kg (round hot tubs), without people.

When planning a garden hot tub on decking, what matters is not only the total weight but also how the load is distributed over the surface. Round hot tubs take up less space, so the load per 1 m² is higher than for square garden hot tubs of similar filled weight.

The table below shows indicative values for the basic Wooden Pools models, without people inside:

The smaller the hot tub and the more concentrated the load, the more it stresses the terrace structure. That is why with the SIMPLE 160 cm model the load per 1 m² reaches approx. 480 kg, while for large square garden hot tubs with water it is around 300 kg per 1 m².

You also need to add the weight of the users to the total mass. At the design stage, the structural engineer will assume an appropriate imposed load and check whether the terrace can safely carry such conditions over the long term.

Can you put a hot tub on a wooden deck?

Yes, if the terrace structure can carry the weight of the filled hot tub and users – from approx. 300 to approx. 480 kg/m² for the unit with water alone. For a deck on joists or above a room, the load-bearing capacity must be confirmed by a structural engineer; an easier solution is a concrete slab or screed under the hot tub, with decking boards around it.

For a wooden terrace you need to distinguish two things: the strength of the finishing boards and the load-bearing capacity of the whole structure (joists, posts, floor slab). The decking boards themselves are not designed to carry such a concentrated load as a hot tub filled with water.

The safest solution is to place the garden hot tub on decking or garden hot tub on:

• a concrete slab or screed approved by a structural engineer,
• pad foundations or point foundations that transfer the load directly to the ground,
• a reinforced part of the floor structure if the terrace is above an internal room.

The terrace boards can then neatly surround this slab without taking the main weight of the unit. This arrangement also makes levelling and servicing easier, as the hot tub stands on a stable, uniform base.

For a terrace on joists, a professional should check the cross-sections, spacing and support of the structure. Only after this analysis can you decide whether a particular hot tub – for example a round 200 cm garden hot tub for a terrace or the smaller SIMPLE – can stand in a specific spot, or whether additional strengthening is needed.

What power supply is needed for a hot tub on a terrace?

Hydromassage hot tubs and square garden hot tubs require a supply of 1 × 32 A 230 V or 3 × 16 A 400 V (Balboa 3 kW heater). The SIMPLE model requires 1 × 16 A 230 V. Plan the socket and cable route before delivery.

In practice, all square models COMA, NOIR, SOMA, FJORD, OAK, NOVA and AURA are prepared for a 1 × 32 A 230 V or 3 × 16 A 400 V connection. The same power range applies to the round TERA and LUNA models, as well as NORD and SAVA with a wood heater, which are additionally equipped with a hydromassage system and Balboa 3 kW electric heating.

The compact SIMPLE 160 cm hot tub has lower requirements – a 1 × 16 A 230 V supply is sufficient. This often makes installation on an existing terrace easier, as many homes already have such a protected line available or require only minor modifications to the electrical system.

Before choosing a specific model, it is worth checking the consumer unit, available connection capacity and the possibility of routing the cable out of sight (for example under the decking boards). A qualified electrician will select the cable cross-section, protection and connection method in line with the applicable regulations.

Hot tub with wood heater or electric heater on a terrace?

On a terrace you can install both a wood fired hot tub and models heated by an electric element with a hydromassage system. The choice depends mainly on your preferred way of heating the water, the space available for the technical equipment and the level of convenience you want.

With a wood heater

The NORD and SAVA models are 200 cm round hot tubs with a wood heater, a capacity of 1 200 l and a dry weight of 230 kg. In addition to the heater they have a hydromassage system with 20 jets and Balboa 3 kW heating, and their power supply is 1 × 32 A 230 V or 3 × 16 A 400 V.

For a hot tub with a wood heater you need to allow space for the heater itself, a safe area around the flue and a zone for storing firewood. On a terrace, the route of the flue and distance from combustible elements is also important and should be discussed with the contractor or chimney specialist.

The NORD and SAVA hot tubs combine traditional wood-fired heating with the advantages of a modern garden hot tub – an acrylic shell, thermo-wood cladding, PUR foam insulation, aluminium frame and equipment including a control panel, LED lighting, ozone generator, thermal cover and steps.

With hydromassage and electric heater

The round TERA and LUNA hot tubs with a diameter of 200 cm have a capacity of 1 200 l, a dry weight of 230 kg and 20 hydromassage jets. They are equipped with a Balboa 3 kW heater and a 1 × 32 A 230 V or 3 × 16 A 400 V power supply.

This is a solution for those who prefer electric heating and full automation – without storing logs and operating a wood burner. The integrated Balboa control system, hydromassage pump, cartridge filter, ozone generator, LED lighting and thermal cover make it possible to keep the water within the desired temperature range throughout the usage period.

At the terrace design stage you need to allow space for the technical enclosure with pump, filtration and electronics, and plan access to these elements for servicing. Also choose a position that allows convenient access to the control panel.

Square garden hot tub

Square garden hot tubs take up more space than round hot tubs, but the lower load per 1 m² makes it easier to install them on a suitably prepared terrace.

The COMA and NOIR models measuring 200-200 cm have a capacity of 950 l, a dry weight of 250 kg and 46 hydromassage jets. COMA has thermo-wood cladding, while NOIR has composite cladding. Both models offer 4 places (2 seats and 2 loungers), a Balboa 3 kW heater and 1 × 32 A 230 V or 3 × 16 A 400 V power supply.

The larger SOMA, FJORD, OAK, NOVA and AURA hot tubs measuring 220-220 cm have a capacity of 1 100 l, a dry weight of 350 kg and 57 jets. Each offers 6 places (5 seats and 1 lounger), an acrylic shell, PUR foam insulation, aluminium frame, Balboa 3 kW heating and the same power standard of 1 × 32 A 230 V or 3 × 16 A 400 V.

If you are looking for a square garden hot tub on decking, a good starting point is the models in the 200-200 and 220-220 garden hot tubs category, which combine advanced hydromassage with complete equipment (control panel, filtration, ozone generator, thermal cover, steps).

Small SIMPLE 160 cm hot tub

The SIMPLE 160 cm model is a compact hot tub with a polypropylene liner, 44 mm thermo-wood cladding and a capacity of 800 l. The dry weight is 160 kg, the number of hydromassage jets is 10, and the power supply required is 1 × 16 A 230 V.

Due to its smaller diameter, the SIMPLE hot tub occupies approx. 2.0 m², but the load on the base reaches approx. 480 kg/m² (without people). This must be taken into account when designing the terrace, especially if it is built on joists or above an internal room.

The SIMPLE model comes as standard with a wooden cover, steps, LED lighting and a cartridge filter. It is a good option if you want a small garden hot tub on decking with simple power requirements and a limited amount of technical equipment.

Hot tub on decking – summary

Before placing a hot tub or garden hot tub on a terrace, it is worth going through a short checklist. This helps you avoid overloading the structure, issues with the electrical installation or difficult servicing in the future.

• Load-bearing capacity of the terrace – check whether the structure can take a load from approx. 300 to approx. 480 kg/m² for the unit with water alone, without people. For a terrace on joists or above a room, consult the design with a structural engineer.
• Base under the hot tub – provide a stable, level and non-moving base (for example a concrete slab or screed) directly under the unit, and plan the decking boards around it.
• Power supply – for hydromassage hot tubs and square garden hot tubs, prepare a 1 × 32 A 230 V or 3 × 16 A 400 V line; for the SIMPLE model 1 × 16 A 230 V is enough. Decide on the cable route and connection point.
• Space for heater or control panel – for models with a wood heater (NORD, SAVA) plan a zone for the heater, flue and logs. For hydromassage models, allow convenient access to the control panel and technical components.
• Access for delivery and installation – check how the manufacturer delivers the hot tub (in one piece or in modules) and whether there is a way to bring it onto the terrace or lift it to a higher level.

If you are considering a specific model, you can use the configurator on the product page, for example for models in the garden hot tubs category, or contact us by phone on +48 888 768 211 to clarify the requirements for the terrace and installation.