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1 October 2020

How to install a hot tub

Use our step-by-step guide to avoid making simple mistakes when installing a new hot tub
Installing-hot-tub-advice
JH
Jade Harding

Installing a hot tub in your garden is actually far simpler than you might expect. In fact, once you’ve decided on and prepped the location, there shouldn’t be much else to do to get it up and running.

However, there are some key things to consider before your tub arrives, including whether you'll need to request planning permission, and ensuring that the ground it will sit on is suitable.  

Find out everything you need to know about installing a hot tub below, or head straight to our guide on how to use a hot tub.

Where to put a hot tub

Preparing the place where you plan to put your hot tub is essential. This will help the installation process go as smoothly as possible, and ensure ongoing maintenance won’t become a nightmare.

There are five main things to consider when settling on a location:

1. Solid ground

Make sure you have a firm, flat, level base to sit the hot tub on. Slabs, concrete, gravel, brick and paving stones should all be fine. You can also buy hot-tub pads to place on more uneven ground to create a sturdy foundation.

Decking is a popular choice, but you'll need to check with a professional to ensure yours can take the weight of the tub.

The same applies for wood-fired hot tubs. You'll also need to invest in a hearth plate to stop any embers from ruining your flooring.

2. Drainage

Your hot tub will need to be drained at least a few times a year, so it’s best to locate it near an existing drain if possible. If there isn’t a suitable space in your garden, you can either install a new drain, or find the lowest part of your garden so you can flush the water straight into the ground when it's time to change it. You can do this using a hose attached the hot-tub plug.

You will inevitably get some water overflow from the top of the tub as people use it, so make sure your flooring won't be damaged by the extra moisture. This is particularly important if you have wooden decking.

3. Power supply

There are two ways to connect your hot tub: plug it into a wall outlet, or attach it directly to your home’s central circuit-breaker box.

Always check which one your hot tub needs before buying.

You'll then need to hire an electrician to either connect your tub to the mains or install a waterproof, outdoor plug socket on to the side of your house if you haven’t already got one.

The socket also needs to be protected by a circuit breaker or residual current device (RCD).

Most wood-fired hot tubs won’t need any electricity to run.

If you’re looking for a recommended electrician you can trust, visit Which? Trusted Traders to find someone near you who has been through our rigorous background checks.

4. Easy access for use and maintenance

Try to leave around 1-2 feet surrounding the hot tub so that any maintenance works can be carried out easily. Close proximity to an outdoor tap and hose will make it much easier to fill the tub after each clean.

You should also ensure you can get in and out of the tub safely.

5. Privacy, noise and aesthetics

As well as the technical considerations, your hot tub's location should also be an enjoyable place to sit – ideally you'd have a spot with a nice view.

If you plan to use your tub while socialising, think about placing it near an outdoor seating area, and ideally close to outdoor lighting so you can use the tub safely at night.

Keeping it near to the house will make it safer and much easier to use when it’s cold and dark.  

Importantly, try to pick a private spot. You don't want to be overlooked by your neighbours, or disturb them when the hot tub is in use.

Can a hot tub go in a shed or summer house?

Yes, a hot tub can be installed in a shed or summer house. In fact, a hot-tub enclosure makes it more likely you'll get year-round use even on rainy days, as well as offering more privacy. They can help to retain heat in the tub, too.

You’ll need to make sure the space is big enough, with plenty of ventilation so the steam doesn’t damage the enclosure. You'll also need access to a power supply.

A permanent gazebo is a good option if you’re happy to commit to a bigger home-improvement project, while pop-up tent gazebos are handy if you’re on a budget and want to stow it away when it’s not in use.

Do you need planning permission to install a hot tub?

This depends on where you live. In most cases, you don’t need planning permission for a hot tub. However, if you live in a conservation area or in a listed building, then it’s likely you will need planning permission.

You’ll also need to check local regulations if you plan to build a permanent enclosure or gazebo around your hot tub, or if you want to it install it in a front garden.

Do you need to add chemicals to a hot tub?

In short, yes. All hot tubs need to be treated with chemicals to ensure they stay clean and hygienic. But the amount of chemicals can vary.

The two most important chemicals when installing your tub are PH controllers and a sanitiser (either chlorine or bromine). 

For all tubs you'll then need to keep these levels balanced on an ongoing basis, as well as using products that help with things like cleaning the filtration. Read more on topping up the chemicals for regular maintenance in our guide to using a hot tub.

Sanitiser chemicals

Chlorine is sightly cheaper than bromine, and very effective at killing bacteria, but does give off gasses that can cause skin irritation for some people. Bromine works well in hot temperatures – it costs a little more than chlorine, but doesn't give off as much surface gas. Both are suitable for hard-shell and inflatable tubs. 

Add the recommended sanitiser granules for your tub size once the pump is running. When starting up, you'll need to shock the water with a higher dose of sanitiser – around 60g of chlorine granules per 1,500 litres. 

The levels are measured using parts per million (ppm). The first treatment should bring the ppm levels to around 5-8. Leave it for an hour or so and then retest. Don't let anyone get into the tub until the levels are at around 3-5ppm for chlorine and 2-5ppm  for bromine. 

Hot tub pH controllers

Then you need to check your pH levels – they should be between 7.2 and 7.8. Anything else means the water is either too acidic or too alkaline, which can cause skin irritation and cloudy water. To balance it out you need to use an increaser or reducer. 

Your hot tub should come with instructions on how to measure pH, and what to do to balance it. 

Once the water is balanced, you're good to go. 

Chemicals in wood-fired hot tubs

Wood-fired hot tubs are slightly different. You'll still need to check and balance the pH levels, but most manufacturers recommend avoiding chlorine-based treatments as they can damage the system. Instead you should use a non-chlorine shock oxidiser once a week to help prevent bacteria build-up and cloudy water. 

Hot tub delivery and installation

The delivery and installation process varies from brand to brand, but most manufacturers of hard-shell and wood-fired hot tubs will offer kerbside delivery.

Some, such as Jacuzzi, will also provide free installation and a consultation with the engineer to run through how to use your new tub. Others charge extra for an upgraded delivery service that includes installation.

Those that offer delivery and installation will ask you about your garden access to ensure the tub will fit when they arrive – if it’s too big, they can also arrange for a crane or a hiab (a delivery truck with a built-in crane) to lift it in.

But if you're getting kerbside delivery, you’ll need to check the dimensions of your hot tub yourself and ensure you have enough space and an access point to get it into your garden, as well as the tools to move it into place – not always an easy task.

For inflatable hot tubs, you’ll only be offered delivery through a normal courier service, and you’ll typically need to set it up yourself.

Regardless of the type of tub, any electrical and base work will need to be completed before delivery.  

Delivery times depend on the brand, what’s in stock, the type of tub you’re getting and where you live. If you’re customising your own hot-tub design this will take longer, too.

Installation times for hard-shell tubs should take around four to five hours, but it’s likely you’ll need to wait at least 10 hours to actually use it. This gives you time to install it, fill it up and heat the water. The same applies for wood-fired tubs.

Inflatable hot tubs only take around 15 minutes to inflate, but heating can take up to 24 hours.

DIY hot tub installation

Once the electrical prep and delivery have been taken care of, installing a hard-shell hot tub shouldn’t be too much of a hassle.

It will come assembled, so you’ll just need to ensure you have the means to fill it up. Then it’s a case of adding the chemicals according to the instructions, and heating it up. If the tub needs to be connected to the mains, however, you will need to get an electrician to finish the job.

Most wood-fired hot tubs will come fully assembled bar the flue. The manufacturer should provide instructions on how to attach this.

Inflatable hot tubs are very easy to set up. You simply need to connect the inflation tube to the inflation valve, and let the pump do the work. Once it’s inflated, you need to fill it, add chemicals and heat it up. Instructions may differ slightly from tub to tub, so always check the manual beforehand.

Once everything’s up and running, check out our guide on how to use a hot tub.