How to build your own cheap DIY Jacuzzi (part II)
Click here for the previous steps
Step 5: Structure (II)
With all this done it is time to apply a generous amount of load bearing straps encircling your DIY Jacuzzi. Don’t scrimp on these because they will be all that’s holding the water in. Depending on the size of your Jacuzzi it will hold approximately one to three thousand liters of water; the weight of a fairly large car. I used ten pairs that were each rated to hold 300kg. You want to space them fairly evenly, but put a little more towards the bottom as most of the pressure will be there. If you keep your Jacuzzi in operation for extended periods of time you may want to shore up these straps every couple of months, just to be sure.
Step 6: The rubber sheet
This is the easiest step so far, put in the rubber sheet. This is in fact the most expensive item you are going to have to buy, we opted for 0,5mm thickness standard garden pond sheeting. There is thicker stuff out there but I dare say you don’t need that. Our sheet has held up against a lot of punishment over three years (broken glass, shoed feet, industrial cleaning agents and scrubbers, heat, freezing cold and being shot with paintball guns) so you could probably go even thinner. As to how much to get, calculate the surface of your Jacuzzi and quadruple it. You need a lot to cover all nooks and crannies and you also want it to cover the outside sides to give your construction a bit of waterproofing.
When putting the rubber in, don’t put it snugly over the sofas but throw it in in a ‘messy’ fashion. Because the water will compress the sofa cushions you will need more rubber sheet when the Jacuzzi is full than when it is empty, but you can only put it in when it’s empty so be sure to put enough. If you put too much it flattens out in a harmless flap, if you don’t put enough it might rupture.
Congratulations! Your very own homemade DIY Jacuzzi is now done. Time to invite all your friends and neighbours! (don't worry, they will never believe you just built your own jacuzzi and probably won't show up)
Step 7: Water & Hygiene
The first thing many people ask is ‘How do you get it hot?’. While we tried many different approaches to heating (electric or using copper tubing through a fire for instance) and they all worked to some extent by far the easiest answer is: Fill it with hot water from the tap. To keep it warm? Top it up with more hot water. Sure, in the long run this will be slightly more expensive than re-heating and treating the same water over and over again, but that long run is measured in many years. An electric water heater + pumping installation will cost you more than the entire project so far, while you probably already have a hot water installation in your house. Just use that.
Any Jacuzzi owner (DIY or otherwise) will be the first to tell you that water quality is massively important. Nothing keeps the ladies from returning to your Jacuzzi parties like staph infections or even just a harmless itchy rash. Unfortunately this is the one area where a DIY Jacuzzi really does fall short of a ‘proper’ one. There is no integrated pumping and filtering system to clean the water. We tried to install one, but again you need fairly pricey equipment to do a proper job. In the end we found the best and cleanest way was to empty out the tub after every use and clean the rubber sheet by hand. I would also advise the use of chlorine tablets and (depending on the quality of your tap water) pH regulators, but these are stopgap measures and cannot keep the filth at bay.
After owning and operating a Jacuzzi for a while you start to appreciate how filthy people really are. This concludes this short manual on how to build your own DIY Jacuzzi, we originally built this as a fun project, just to see if it could be done. We expected it to break possibly the first time but for sure within a month. Three years later we abandoned it because we left the house, but it was still going strong at that time. If you have any further questions ask them in the comments, or let me know how you’re getting on with your own Jacuzzi project. I would love to hear your experiences! Here are some pictures of the finished product in action