Hot tubs come in many different sizes but as a guide here are some typical dimensions;

In terms of height, most hot tubs are between 75 and 95 cm in height, bit some can be higher.

One of the most overlooked aspects of a hot tub installation is delivery access. Most hot tubs are delivered on their side, so even if your garden has room, making sure you can get the hot tub in is important.

If your access is tight, speak to your supplier about using a Hiab or crane to lift it over a fence or the house itself.

Remember, hot tubs are heavy 1,500 kg or more when filled, so a solid, level base is essential. Also, don’t forget to allow space for the step at the front of your hot tub. These are usually 40cm or more in depth. At the back, you will need between 20 and 40 cm clear space for the cover to sit in when it is lifted using a cover lifter.

Suitable bases include a bespoke concrete pad, a patio and reinforced decking. There are also mesh systems available that you can fill with gravel, which is installed correctly can provide a more cost effective solution than a concrete pad.

Avoid placing a hot tub directly on grass or bare soil, as these are unstable and can cause damage over time.

Servicing Clearance

Even if your hot tub fits perfectly into a tight spot, you still need to leave space around it for future maintenance or repairs. For most hot tubs, access to the front is the most important as this is where you access the majority of the working parts, like the heater, control panel and pumps.

Ideally, you will allow at least 60 cm clear access all around in case an engineer ever needs to gain access to carry out a repair. If you don’t have this, then all is not lost. It is possible to drain and push the empty hot tub to create access to a side otherwise blocked by a fence or wall for example.

If you’re building your tub into decking, make sure to leave removable access panels or hatches and a crawl space for an engineer to use. Any good landscaper should be able to create this without too much of a problem.

The other thing to remember about sinking a hot tub, is make sure there is adequate drainage from the hole. This could be drainage pipes to a soak away or a sump pump which pumps out rain water as necessary.

Plan for the Area Around the Hot Tub

To really enjoy your spa, think about the surrounding space as well. As already mentioned you’ll need extra room for the steps and cover lifter but think about access, paths and whether you might add features like a gazebo, outdoor bar and lighting around it.

The more thought you give to the environment around the tub, the more comfortable and attractive your setup will be.

Electrical Space Requirements

For UK installations, there are two main types of hot tubs, those that can run off a standard 13 amp supply and the more premium ones that require a larger 32 amp cable.

Leave room for safe cable runs and ensure your layout includes space for the rotary isolator and access to the power source.

Choosing the right base for your hot tub is essential to ensure its longevity, safety, and performance. A hot tub filled with water and people can weigh over 2 tonnes, so a strong, level, and stable foundation is a must. Below are the most common base options, each with their own advantages:

Concrete Base

A concrete slab is one of the most popular and reliable options. Ideally, it should be at least 4 inches thick and reinforced with steel mesh for added strength. It provides a perfectly level, solid surface that can easily support the weight of the hot tub. Concrete is durable, weather-resistant, and low-maintenance, making it ideal for long-term use.

Patio Paving Slabs

Many customers opt for paving slabs, provided they are laid on a sturdy sub-base of compacted hardcore and sand. The slabs must be level to avoid putting uneven pressure on the hot tub frame. This option is both functional and aesthetically pleasing, blending well with garden landscaping.

Decking

Decking can be a great choice if properly reinforced. Standard garden decking isn’t usually strong enough, but with additional support beams and footings, it can easily hold the weight of a hot tub. Composite decking is also a popular low-maintenance option, offering resistance to water and rot.

Gravel with Hot Tub Pads

For a more flexible solution, some use a compacted gravel base topped with interlocking plastic hot tub pads or tiles. The gravel allows for drainage, while the pads provide stability and protect the underside of the spa.

We are here to help and offer advice so don’t be afraid to pick up the phone and ask for advice.

One of the most important aspects of installing a hot tub is ensuring it has the correct and safe electrical supply. Hot tubs require a dedicated electrical setup, tailored to their power needs.

Cabling Requirements

Hot tubs require an armoured cable, known as SWA (Steel Wired Armoured) cable, to connect them to the main electrical supply. This type of cable is durable, waterproof, and protected against accidental damage, making it perfect for outdoor installations. The thickness (gauge) of the cable depends on the power rating of your hot tub and the distance from the house consumer unit (fuse board). Generally, 6mm or 10mm SWA cable is used, but it’s essential to have a qualified electrician calculate the exact size based on load and distance to avoid voltage drop issues.

Isolator Switch

For safety and convenience, every hot tub installation must include a rotary isolator switch, typically rated at 32A or 45A. This switch is installed outdoors, close to the hot tub (not closer than 2m) but at a safe distance, allowing the power to be quickly disconnected in case of an emergency or when maintenance is needed. It also ensures compliance with UK electrical regulations.

Amp Ratings & Power Supply Types

Hot tubs come in two main electrical categories:

• Plug & Play Hot Tubs (13A Supply)

  These hot tubs run on a standard 13A supply and can be plugged into a Caravan socket, but should never be connected in to a standard 3 pin, outdoor socket. They are simpler to install and cheaper in terms of electrical setup. However, they usually have smaller pumps and heaters, which may result in slightly slower heating times or reduced performance compared to higher-rated models.

• Hardwired Hot Tubs (32A, 40A, 45A, 50A Supplies)

  Larger, more powerful hot tubs require a dedicated hardwired connection, typically rated between 32A and 50A, depending on the number of pumps, heaters, and additional features like lighting or audio systems.

  32A is the most common for standard premium hot tubs.

  40A and above may be needed for large hot tubs with multiple jet pumps and rapid heating

These require installation by a qualified electrician, including an RCD-protected circuit and compliance with Part P building regulations.

Always consult your hot tub retailer and use a certified electrician familiar with hot tub installations to ensure your electrical setup is safe, compliant, and tailored to your specific model. Proper installation prevents safety risks and ensures smooth operation for years to come.

Supplying water to your hot tub is straightforward, but there are a few important considerations to keep in mind to ensure optimal performance and water quality.

Most hot tubs are not plumbed in permanently. Instead, they are filled using a standard garden hose connected to your outdoor tap. This makes them flexible and easy to install, as no dedicated plumbing work is required. Simply position the hose inside the spa, fill to the recommended level (usually just above the highest jet), and you’re good to go. Water changes are typically done every 3-4 months, depending on usage and chemical balance. It is advisable to fill your hot tub through the filter housing to push air out of the system, otherwise you run the risk of air locks developing when it is full. These can sometimes be hard to clear.

When it’s time to empty your hot tub, water can be drained via the inbuilt drainage valve, usually located at the base. Some hot tubs allow connection to a standard hosepipe for easy draining to a suitable outdoor area, drain, or soakaway. Alternatively, you can use a sump pump to drain it more quickly. These are relatively inexpensive and readily available online.

Water Softeners – Do You Need One?

In most cases, it is not recommended to fill the entire tub using softened water. While softened water helps prevent scale buildup, it often has a lower calcium level, which can lead to corrosion of metal components and damage to heaters and pumps over time.

Instead, many hot tub owners in hard water areas choose to fill using a standard outdoor tap (without softening) and then manage scale and hardness levels using specialised hot tub chemicals like scale inhibitors. Alternatively, if you do use softened water, it’s advisable to balance the calcium hardness afterward to ensure it stays within the ideal range (typically 150-250 ppm).

Once filled, always test your water using test strips or digital testers to adjust pH, alkalinity, and sanitiser levels before use. Keeping your water balanced from the start ensures a longer-lasting, trouble-free hot tub experience.

Draining your hot tub is a simple but essential part of regular maintenance. It helps keep the water clean, protects internal components, and extends the life of your spa. Here’s how to do it right:

1. How often should you drain it?

As a general rule, plan to drain your hot tub every 3 to 4 months. If you’re using it heavily or have a smaller model, you may want to drain and refill more frequently.

2. Turn off the power

Always switch off the hot tub at the isolator or breaker before draining. This protects the pump and heater while there’s no water flowing through them.

3. Use the built-in drain or a submersible pump

Most Jacuzzi® hot tubs have a built-in drain valve near the base. Simply attach a garden hose, open the valve, and let gravity do the work. Connecting a hose is especially useful as it allows you to divert the water away from the hot tub, preventing pooling around the base.

You can direct the flow toward a drain, gravel bed, or further down the garden — just be mindful of where the water ends up. It’s best to avoid emptying onto lawns, sensitive flower beds, or newly planted areas, as spa water (even when untreated) can affect soil and plant health.

For faster draining, especially if your tub is in a low spot or the hose route is long, a submersible pump can help speed things up dramatically.

4. Clean as you go

Once drained, take the opportunity to give the shell a clean using a non-abrasive spa surface cleaner. Wipe down the waterline, jets, and seats before refilling.

5. Refill with care

Close the drain valve and start refilling through the filter compartment — this helps reduce the risk of airlocks. Once filled, switch the power back on, balance the water chemistry, and you’re good to go.

Top tip:

Avoid draining during freezing temperatures unless absolutely necessary, as residual water in the pipes can freeze and cause damage.