5 Things Most Buyers Never Know About Cedar Hot Tubs

A cedar hot tub is any outdoor tub built from Western Red Cedar, from a traditional cedar barrel hot tub made entirely of wood to a cedar-clad tub with a metal structure underneath. They can be heated by wood, electricity or both, pared down for an off-grid cabin or fitted with filtration for daily use at home. Five things about them catch most buyers out, and they decide whether the tub is still in use in twenty years.

1. Cedar is the outside. What holds the water is the question

Two very different tubs get called a cedar hot tub. In a traditional barrel hot tub the wood is the vessel: staves held by steel bands, sealed only because the wood has swollen. In a cedar-clad tub, the water sits in a structure of another material and the cedar is the exterior, the seating and the lid.

AlumiTubs pioneered the second kind in 2001, with a riveted marine-grade aluminum structure under Canadian Western Red Cedar. The reason is what happens to all-wood construction over time: the grain harbors bacteria that a rinse does not reach, the staves move with every wet and dry cycle, and eventually the tub leaks. An aluminum structure does not absorb water, so it can be fully insulated on every side, filled from a lake or the ocean, and drained without consequence. It is also the reason a cedar hot tub of ours weighs 200 to 300 lbs empty rather than several hundred more. Every hot tub material compared sets the trade-offs out plainly, including where aluminum is not the right choice.

2. An all-wood tub has to stay full

This is the one nobody mentions in the showroom. A cedar barrel hot tub seals because the staves are swollen. Leave it empty for a few weeks and the wood contracts, gaps open, and the next fill leaks until the wood swells again. So the tub is kept full year round, which means standing water to treat, algae in the grain, and in a cold climate a real freeze risk, because the one thing you cannot do is drain it for the winter.

A cedar-clad aluminum tub has none of that. Drain it after a weekend, leave it empty until spring, fill it the day you arrive. For a cabin, a rental with gaps between bookings, or anywhere with a hard freeze, that single difference decides the whole ownership experience. What to expect in your first year sets the two side by side, season by season.

3. Heating is not one decision

Cedar hot tubs are heated by wood, by electricity, or by both in one tub. Wood fired needs no power at all, heats from cold in about two hours on a Small, three on a Standard and five on a Large, and is the choice for off-grid properties and for anyone who wants the fire to be part of it. Electric holds a set temperature and includes filtration, so the water is ready without lighting anything, which suits daily use and guest properties. A Hybrid carries both, run alone or together, and keeps the tub in use through a fire ban.

The part buyers miss is that on an AlumiTub the heating can change later. A Wood Fired built with the optional compatibility ports can take electric heat and filtration years afterward, and the 120V filtration converts to 240V heating with the same equipment. We do not offer propane or gas. The heating options guide compares all three side by side, and how long it takes to heat covers running a fire well.

4. Depth matters more than diameter

Many people have been disappointed to receive a cedar hot tub that is too shallow, leaving shoulders in the cold air while the lower half soaks. Bath-style and oval tubs solve it by making you recline. A round tub solves it with depth.

Every AlumiTub is 38 inches deep as standard, which puts 21.5 inches of water over the seat at the recommended fill, and 44 or 48 inch builds are available with bench heights to match. That is the figure to ask any manufacturer for, and most cannot give it. Diameter is the easier decision: lay a garden hose out at 5, 6 and 7 feet, sit inside each with the people you will actually soak with, and see how it feels. The Standard at 6 feet, seating five, is the one most families choose. What size you actually need works through it.

Round also matters for a reason beyond depth. In a barrel hot tub everyone faces inward and the view runs all the way around. In a rectangular tub it is a shared bath.

5. The cedar looks after itself

New cedar is a warm red-brown. Left alone outdoors it silvers to a soft gray over a couple of seasons, which is the wood weathering rather than failing, and many owners come to prefer it. If you would rather keep the original tone, the boards can be sanded back or finished with a copper-free stain or clear coat. Copper-free matters on an aluminum tub, because copper reacts with the structure.

What the cedar never does on a cedar-clad tub is carry the water, so a board that weathers badly is replaced on its own rather than the tub being rebuilt. Western Red Cedar is naturally rot and insect resistant, one of the best insulators of any North American softwood, and fully biodegradable at the end of a very long life. Ours is milled by a neighbor on the Sunshine Coast from trees that have already fallen. Why AlumiTubs use Canadian Western Red Cedar covers the wood and how to care for it.

Common questions

What is a cedar hot tub?

Any outdoor hot tub built from Western Red Cedar. In a traditional barrel hot tub the cedar staves are the vessel itself, sealed by the wood swelling. In a cedar-clad tub the water sits in a structure of another material, such as marine-grade aluminum, and the cedar forms the exterior, the seating and the lid.

Do cedar hot tubs leak?

All-wood cedar tubs seal only while the staves are swollen, so they leak after being left empty and can develop leaks over time as the wood moves and the grain harbors bacteria. A cedar-clad tub with an aluminum structure holds water without depending on the wood, so it can be drained and left empty between uses and through winter.

How deep should a cedar hot tub be?

Deep enough to cover the shoulders sitting upright. AlumiTubs are 38 inches deep as standard, with 21.5 inches of water over the seat at the recommended fill, and 44 or 48 inch builds are available. Ask any manufacturer for the water-over-the-seat figure rather than the tub height.

Do you have to stain a cedar hot tub?

No. Left alone, cedar silvers to a soft gray over a couple of seasons, which is weathering rather than failure, and many owners prefer it. To keep the original tone, sand the boards back or use a copper-free stain or clear coat on the exterior only, never on interior seats or the firebox fence.

Sizes, heating options and the 25 year structural warranty are on the cedar hot tubs collection.