TikTok Shows You How To DIY A Wood-Fired Hot Tub Just In Time For Summer Nights

Soaking in a hot tub can bring a multitude of benefits like stress relief, pain relief, and improved cardiovascular health, so it's no wonder that they are such popular investments. A standard hot tub can cost anywhere between $2,000 to $11,000, with the average cost falling somewhere around $6,000, according to Angi's List. Of course, that doesn't include the electric or gas bill, maintenance costs, or repairs that you'll need to keep your hot tub in good, working condition. Plus, you'll have to learn when and how to shock your hot tub to keep it from turning into a bacteria-laden bucket. For some people, the cost and effort of a hot tub is worth it for the relaxation it brings, but what if we told you that you could make your own affordable, easy-to-maintain, and totally off-grid hot tub with a simple TikTok hack?

If you're daydreaming about soaking the summer away under the stars, you don't have to blow your budget on a fancy high-tech hot tub. A TikTok video, shared by Sydney Emett (@Lifesrad), shows how she and her husband, Alex Emett, built their own wood-fired hot tub. Here's how they did it, the questions they answered along the way, and the science behind the hot water magic. 

Grab a coil kit and a container

In their viral TikTok video, Sydney and Alex Emett are seen stacking pave stones to create a fire pit around a large steel coil. Their steel coil kit with tub attachments was purchased for about $650 from Salty Barrel Hot Tubs, an Australian-based company specializing in portable, wood-fired hot tubs. Of course, any thick steel coil would likely work for this simple wood-fired hot tub hack, as long as the metal itself is durable enough to withstand high heat — Salty Barrel's coil is made with 304-grade stainless steel. "The only tools we needed were pliers to get the fittings on, a screwdriver to tighten the hose clamps, and then a drill for the inlet and outlet," explained Alex (via TikTok). 

The heating coil system can be attached to nearly any large, heat-safe container or Salty Barrel's portable hot tub base. In the TikTok, Alex and Sydney use a 170-gallon CountyLine brand tub, which can be purchased for about $199.99 at Tractor Supply Co. Alex attaches the water inlet and outlet hoses to the barrel by drilling two perfectly sized holes, then uses the attachments included with the kit to make the seal watertight. After filling the tub with water and lighting a fire inside the fire pit, steam can be seen rising from the tub as the two happily hop in! As a charming bonus, the fire also provides nice ambient lighting and extra nearby warmth for moonlight soaks. 

Cool science and hot safety tips

This DIY luxurious hot tub is surprisingly eco-friendly and affordable, but how does it work? And is it safe? The hot tub doesn't use electricity or natural gas to heat the water; it doesn't even need a pump to push the water through the coil. Instead, the system relies on a scientific phenomenon called thermosyphoning. Cold water naturally settles at the bottom of the tub, where it flows in through the water inlet and into the large metal coil. Fire heats the water, which causes it to rise through the coil, getting hotter and hotter as it goes. When it flows back out through the water outlet, it pulls more cold water into the coil behind it, and the process repeats!

One potential downside to the setup is that it can take a while for the water to heat — roughly 1 to 2 hours for a tub of the Emetts' size. Some folks may also worry about the water getting too hot due to the lack of temperature controls, but as Alex explains (via TikTok), "It's not like we're boiling this thing. It's literally just 105 to 110 degrees." The couple also keeps a cold water hose nearby to lower the temperature inside the tub if needed. Of course, once the water is warm, you can also douse the fire to stop the thermosyphoning process. Cleaning the tub is also easy and chemical-free; drain, wipe, and cover it when not in use.