Can I Put A Hot Tub On My Raised Decking Area?

March 2022
Anton White

Yes! A decking area is a great place for your hot tub. For a start, it will minimalize dirt getting into the tub, and will also mean you will also have space for seating and is easily accessible.


But you will have to make sure that your decking is supported and has the strength to support it. Hot Tubs are very heavy once filled with water and people, so joist spacing and supports will have to be closer together. In this article I will go over three key areas to consider.

- Joist Spacing

- Support Spacing

- Ground Preparation

- Joist, decking, and support material


Joist Spacing

When building your decking area, you will want to plan out where your hot tub is going to go. Once you know where this is, halve the spacing in between joists. This will ensure that the deck boards do not have to span too far between supports. 150-200mm in between joist centres is a safe option.


Support Spacing

Supporting the joists is also very important. Depending on the recommendations between support for joists, reduce this up to half to be extra sure that there is no way that the joist can be too weak to support. For example, our 72mm aluminium joists can span 1.2m, but we would recommend reducing this to 600mm so that there is no way that the joists would struggle for strength.


Ground Preparation

The best way to prepare the ground for supporting a hot tub on top of a suspended paving/ composite decking system, is the have a solid concrete base, at around 100mm thick. If this is not possible because the ground is on a slope or any other reason, we recommend removing soil where the pedestal support will be going and pour a small concrete pad (30x30cm) underneath each pedestal. We do not recommend placing the pedestal straight onto grass or mud due to the weight of the hot tub on top. It would more than likely sink over time.


Joist, decking, and support material

Wooden joists, decking or supports are likely to rot within a few years of installation. This is because of the high water volume that it will experience with the humidity that a hot tub creates. We recommend working with joists and decking that is not badly affected by water. For example aluminium joists or composite decking. This will not rot and are sure to last for many years to come.




In conclusion, we recommend you double up on supports and joists where your hot tub is going, this will make sure that there is no possibility of anything going wrong further down the line. Any technical questions regarding the strength of our joists or pedestals? Contact our friendly team, they’d be more than happy to help.


Now that you've read more about what materials you may need for a project like this, you may begin thinking about using our materials as an option for your hot tub project. With so many options available, we know it can seem like a big decision to make. Why not begin by ordering one of our free sample boxes to help you choose which style will best suit you? You can also call us for any special sample requests such as aluminium joists or pedestals

You can call us on 0208 159 2999 or send us an email to to get quotes, guidance and any technical support with your plans. If you think you will require the help of a professional installer, we are happy to recommend one to assist.