Hot Tub Installation Guide

Posted by Nick Clamp in Hot Tub Installation Guides on 24th August 2020

Have you dreamed about installing your perfect hot tub but don’t know how? WhatSpa? is here to help with our simple 7 step pre-delivery hot tub installation guide.

Creating a domestic outdoor oasis, equipped with a relaxing hot tub is a dream for many of us.

Unless you are a hot tub aficionado, pool engineer, or landscape gardener, the prospect of installing a portable spa correctly and creating a complementary environment could be more than a little daunting.

Which is why we have created this step-by-step pre-delivery guide to help you with your planning and realise your perfect wet leisure project. Get it right and you will have something that will enrich your leisure time, health and relationships on a daily basis. And you really can’t put a price on that!

Step 1. Do your homework

Photo © All Weather Leisure

Most reputable dealers will carry out a site survey at your home, before your delivery date, to give you an idea of what is possible and advisable within your garden/home. They will also hold your hand throughout the whole process, and will work closely with landscapers and electricians to ensure a seamless installation.

Your first step should be to identify what kind of hot tub you want. Look at what you want from the spa with regards to size, seating, hydrotherapy jets, features and general appearance. If you have a smaller area then make sure you read our small hot tub guide to maximise the space. This is where websites like WhatSpa? come into play, as you can research different products from various brands and find the best hot tubs.

Before you go headlong into wet testing and buying, measure the area of your garden that you have earmarked for your shiny new spa; and even use string, or tape, to plot the footprint of the spa to ensure it will fit comfortably.

It is wise to get your shortlisted hot tub dealers to conduct a site survey before you commit to buying, or certainly within seven days of purchase, as this is the timeframe that will enable a full refund if there are any unforeseen issues with the delivery process.

Remember that hot tubs are typically delivered to site on their sides via a specialist ‘spa dolly’ or ‘spa sled’. If you are doing your own pre-delivery measuring, the height of the spa when it is sitting flat on the ground plus about one or two inches for packaging is the critical clearance width that you will need at every point on the route, from the kerbside to your chosen location. Hot tubs do not bend in the middle, so be particularly careful with any bends or kinks in the route and look out for outdoor taps, downpipes or boiler flues that may jut out from walls along the way. If you are in any doubt, ask the dealer to do a site survey.

If you decide to employ the services of a separate landscaper make sure there is plenty of communication between yourself, the landscaper and hot tub installer. There’s no point having your hot tub delivered when the groundworks aren’t suitable or complete.

Step 2. Choosing your position

Photo © North Spas

Although the tendency is to put a spa at the bottom of your garden, remember that the further you locate your tub from the house, the longer your walk to it. There is something to be said for having your tub closer to home, particularly when the cold weather draws in. Common sense says the nearer you are to your tub, the more likely you are to use it!

Does your chosen spot afford you privacy from the neighbours? Generally, the closer you position your hot tub to the house, the less overlooked you will be due to the acute angle from neighbour’s windows.

Is there a pleasant view from your tub? Have a walk around your garden to visualize the best location. As silly as it sounds, make an outline of your hot tub’s perimeter dimensions using tape or string, grab a low-seated garden chair and sit on each side and corner to give you an idea of the view you will have. This is particularly important if you are choosing a ‘lounge-seater’ model as it is important that your views from the lounger are facing the best aspect of your garden view.

Consider the route from the house to the hot tub – a clean path will mean less grass and soil gets transferred from feet to spa. Avoid placing your spa underneath a tree, as the last thing you want to do is continually pick out decaying leaves from your water.

If you have children then consider whether you can see where they are and what they are up to, if say, you are relaxing in a nearby patio area while they splash around in the spa… or vice versa!

It is advisable to have an outdoor tap and hosepipe within reach, and desirable to have an accessible drain, which makes emptying your tub easier. For safety’s sake, avoid placing your hot tub within three metres of overhead power cables.

Step 3. Plan your landscaping

Consider what you want out of the landscape. Do you want it purely for relaxation, or do you want an area for entertaining as well? If you want to create something special that will wow your guests, there are plenty of additional ‘props’ that can add to your outdoor living lifestyle such as garden buildings and automatic covers, outdoor bars, BBQs, outdoor kitchens and even pizza ovens. At this stage you can also start to consider the type of hot tub housing that is available to maximise your hot tub enjoyment.

Philip Edwards is a landscape gardener specialising in wet leisure designs. Philip says there are a number of factors to consider when planning your ideal garden. “You need to think about whether you want the spa area hidden or visible, how easy it is to get power to the area, and can you easily drain the wet area,” says Philip.

“How do you want to link the area in with the rest of the garden? Will noise from the area cause a problem with neighbours? Is lighting or rain protection required?”

So what are the common mistakes to avoid? “Gravel or grass around the tub can end up in the tub from feet and block access to maintenance points,” says Philip. “Avoid slippery or rough paving, use good treated softwood/hardwood or synthetic decking that does not splinter easily, avoid herbaceous or deciduous plants and choose materials around the area that will link in with the rest of the garden. The trends for 2019 are for clean, contemporary garden design, complemented with evergreen planting with contrasting colours that create movement.”

Communication between client, hot tub installer and landscaper is vital, says Philip. “For a high-end designer look, it is essential to have the project managed, which could be by the designer or the landscaper – very rarely can the client manage this themselves. It is better to choose a landscaper who can cover all the aspects in-house, with electrics being the exception,” advises Philip.

The trend for some hot tubs – particularly larger models – is to have them ‘semi-sunken’ into the ground. If this is the effect you are after then it may require some ground excavation, which will have an influence on the length and cost of your project.

Talk to your hot tub dealer and ask them to recommend a landscape gardener or architect. Their experience will be invaluable, so use it.

Step 4. Solid hot tub base

Photo © Urban Cedar

Your hot tub needs a good solid, level foundation. A hot tub on its own is a heavy item, typically weighing in at around half a tonne when empty. Fill the same tub with water and four people and that weight can rocket up to two-and-a-half tonnes. So the area you sit your tub on must be able to support the stresses and strains associated with this considerable weight.

What you don’t want is a spa plonked half-heartedly on a patch of gravel. If the support is inadequate your tub may shift, putting stress and causing possible damage to your shell. It’s common sense but putting your spa on a slope will lead to uneven water levels.

If you are installing your tub on a concrete base make sure it is at least four inches thick. If you plump for decking make sure the structure is up to the task of coping with the stresses placed on it. As a general rule the cross-members supporting the deck should be 4”x 2” and no more than 18” apart.

Your spa may look better sunken – partly or completely – rather than on top of the base structure. If you have an undulating garden don’t be afraid to give it some elevation, although bear in mind that if you do suspend your spa the decking will have to be robust enough to cope with the stresses and weight. Remember to build in access points for an engineer to get access to the equipment bay for servicing later.

Step 5. Hot tub electrical requirements

You don’t need a permanent water supply for a hot tub or garden spa, but you will need a suitable electrical supply to run the tub.

Most reputable hot tub showrooms will be able to recommend a local trustworthy electrical contractor who is au fait with the ins-and-outs of hot tubs, so don’t be afraid to ask. They will also be very happy to liaise with your chosen ‘sparkie’ regarding the spec of the spa and the resultant power supply requirements.

When appointing an electrician to prepare your hot tub electrics check that they are a suitably qualified electrician. Do not attempt to install hot tub electrics yourself if you are not qualified. The Government introduced a new ‘Part P’ law in January 2005, which demands that most electrical work in UK households is only carried out to Minimum Technical Competence (MTC) standards. This law means that electrical safety requirements have been included in a new Part P of the Building Regulations.

Part P Explained

The law states that anyone carrying out fixed electrical installations in households in England and Wales must ensure that electrical installations are:

  • Designed and installed to protect against mechanical and thermal damage, so that they do not present electric shock and fire hazards to people.
  • Suitably inspected and tested to verify that they meet the relevant equipment and installation standards.

It is now against the law to have a new circuit installed in your home without having it inspected and tested to ensure it is Part P compliant. Make sure that your electrician is Part P registered and that you receive a Part P certificate after the hot tub electrical supply work is completed. This will need to be kept on file as all electrical works will need certification evidence should you ever decide to sell your home at some point in the future.

Your hot tub retailer can liaise with your electrical contractor regarding the exact specification for your spa but you must meet the following specification:

  • The hot tub must be hard-wired on its own fused spur back to your household consumer unit (i.e. the tub should not be sharing a supply with any other appliances).
  • The hot tub should be protected by a sufficiently rated MCB (mains circuit breaker) and should cover the maximum amperage pull of the spa plus 25 per cent to allow for brake torque (i.e. the extra rush of current when pumps are first started). So a hot tub that has a maximum current draw of 20 amps should be fitted with a 25amp MCB.
  • The hot tub should also be protected against earth faults by an RCD (residual current device). This is a trip switch, which prevents danger of electric shock from damaged or waterlogged cables and connections. A suitably rated 30mA RCD is recommended.
  • Outdoor cabling should be protected from damage by either laying protective ducting (pvc pipe) below ground or by using ‘steel wired armoured’ (SWA) cable. Your electrician will calculate the size of cable required depending on the loading and the distance from the mains supply. Six mm2 3-core SWA cable is perfectly suitable in most cases but always consult an electrician first.
  • An IP65 (waterproof, minimum 45-amp) rotary isolation switch is also recommended so that the hot tub can be isolated outdoors in an emergency or for service work. This is simply a rotary on/off switch but should be sited more than two metres away from the hot tub so that bathers cannot be in the spa whilst touching the switch.
  • Leave a tail of SWA cable from the isolation switch that is sufficiently long to feed inside the spa cabinet and reach the load box within the hot tub equipment bay. Contact your dealer to confirm the requirements.

Once electrical installation is complete, lock off the isolation switch in the ‘OFF’ position, coil up the SWA cable tail and tape off the exposed wires at the end of the cable to prevent water ingress in the period between now and delivery day.

Upon delivery the hot tub supply can then be directly hard-wired into the load box inside the spa. Waterproof gland packs should be used to prevent ingress of water on all outdoor electrical connections (two at the isolation switch and one inside the hot tub). Ensure that all earth cables are clearly colour-coded with green/yellow insulating tape or earth sleeve.

Finally, once the hot tub is wired, filled and working, your electrician will need to conduct their tests to ensure Part P compliance and also issue your Part P certificate.

Step 6. Delivery day

Photo © All Weather Leisure

The delivery of your hot tub is an essential part of the process – we’re not talking about a courier dropping off a Blu-ray player here! Hot tubs, by their nature, tend to be large, heavy and bulky items. If all a retailer offers to do is deliver it to your kerbside without installation then head for the hills!

Factor in how easy or how difficult it will be for a dealer to deliver your spa to the exact spot required. If you have easy access to the required spot then it may simply be a task for your dealer to wheel or slide the spa into position on a ‘spa dolly’ or ‘spa sled’. You may have to remove fencing or gates to enable access.

However, if you have restricted access to your garden (a particular issue for people living in terraced streets), there is every possibility that the spa will have to be craned into position. This will, of course, affect the cost of installing a hot tub.

If you do need a crane delivery, there are two types of offerings from crane companies. A ‘contract lift’ is a full service contract where the crane company is responsible for everything including writing method statements and risk assessments, liaising with transport authorities for road closures and also providing banksmen and insurance cover. The cheaper ‘crane hire’ means that you are responsible (and liable) for all of these extras.

We always recommend that you opt for ‘contract hire’ for the protection and convenience that it offers. Note that hire time starts from when the crane leaves the depot so always opt for a reputable local crane hire company and get several quotes to ensure best value.

Step 7. Up and running

Photo © Hot Tubs Hampshire

Once your hot tub is delivered, placed in situ, filled with water and the electrical supply is installed, your hot tub installation team should ‘commission’ the hot tub and check that everything is fully operational before ‘handing over’ to you with a thorough training of how all of the hot tub features work.

Reputable dealers will fill it up and ensure that your water is safe and balanced with the appropriate water care products. They also provide information about testing and maintaining clean water, and will lead you through the process before leaving you alone to enjoy your new pride and joy.

Ensure that the spa has a comprehensive instruction manual written in clear English, as this is a legal requirement for all electrical goods.

Keeping it simple

Not everyone wants the full spa and landscaping works. If you want to keep things ultra-simple then there are a number of affordable spas on the market that offer ‘plug and play’ practicality.

Many hot tubs manufacturers are now producing models that can run on a 13-amp supply. They will still need to be connected to a waterproof outdoor socket which is RCD protected for those who don’t want the hassle of putting in a dedicated electrical supply. We’ve recently published a comparison of 13 amp vs 32 amp hot tubs.

All you have to do is find a sturdy, level surface, fill your tub with water, balance the water to make sure it is clean and safe and away you go!

About the author

Nick Clamp

I am the Editor-in-Chief at WhatSpa? Media Group and my job is to keep you informed about the very latest hot tubs on the UK market... the best job in the world! When I'm not being deluged with press releases and hot tub brochures I enjoy keeping fit and participating in endurance events including triathlons and distance running.

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