Building cedar hot tubs is a great way to create a hot tub that is lightweight, strong, and also happens to be pleasing to the eye.
Step 1 - Basic Set Up
First and foremost, find a good place to put your hot tub. You should have a level plot of land that is capable of supporting the tub's entire weight. Next, you are going to want to cut lengths of your cedar wood that fit the size of your hot tub. The dimensions that you choose are going to vary based on the desired size for your hot tub. Smaller tubs and larger tubs are going to have varying dimensions, for example.
Step 2 - Prepare the Wood
Next you are going to want to punch holes in your tub bottom with a hole saw that are fitted to the size of the suction fittings of your tub. Your holes should never be more than five inches away from the edge of this bottom piece as they should not be easily reachable. Next you will want to punch holes in the staves where your hot tub jets will be placed using the hole saw. Finally, cut a hole in a stave for inserting your hot tub skimmer. It should be placed near the holes for suction fittings.
Step 3 - Chine Joists
Now you should place all of the chine joists down on the ground to support your hot tub, securing them with bolts to the concrete where your hot tub will permanently rest. The smaller joists should be placed on the ends and the larger joist should be placed in the center. The tub bottom should be placed on top of these joists and should be secured into place using nails or bolts. Make sure that they are pounded completely in so that nothing is sticking up or out.
Step 4 - Suction Fittings
The suction fittings should be fit in and secured in the holes cut for them, attached to the bottom of the tub. The staves should be attached around the bottom of the tub, interlocking with one another. Tub bands should be slid over them, with one resting 20 inches from the top and then another one resting 20 inches from the bottom of the tub. The tub bands should be tightened until they are completely firm.
Step 5 - Final Steps
Hammer nails above and below the tub bands to keep them in place, making sure that all of the nails are evenly spaced around the diameter of the tub. Seal every single seam in the tub using an epoxy sealant, making sure that the entire tub is completely watertight. The sealant should be kept warm and allowed to dry for a period of at least 24 hours. The bench supporters should be fit in a ring around the tub, taking care not to allow them to cover any holes you created. Now the benches can be installed and nailed or bolted in.
The tub skimmer should also be attached and the PVC pipe should be connected to the suction fittings and made watertight using PVC sealant. The water pumps and other accessories should also be attached at this time, using PVC sealant to make sure that everything is watertight. There should be a water pump for high speed jets and one for lower speed jets as well. The thermowell should be attached to the water filter and the water heater, and the timer and its control box should also be installed at this point.