Confused about best practices in hot tub frame construction? Steel, PVC, or wood? In this article we will take a deep dive into steel frame hot tub construction with the predominant material of choice being galvanized steel.
First off, let’s look at overall cost of materials from a manufacturing standpoint. In general, a wood frame hot tub is less expensive than a steel frame. However, the difference in cost will also depend on whether the wood frame of the hot tub is made of all treated wood or if it’s just the base and also how stout the frame is built. Similarly, one would also need to consider the gauge of steel (lighter versus heavier) and respective costs. In essence, a robust and fully treated wood frame may not be as big of a difference in price than a light gauge, sparsely constructed metal hot tub frame. You have to really look under the hood when comparing wood and steel to see what type of material and what level of construction each hot tub manufacturer is using. You can’t just get caught up in a good sales pitch.
Second, let’s take a look at strength of material. A steel frame is going to be stronger than wood in general, however, we will refer to the example above in the case that one frame maybe be designed and constructed better than the other which will make a meaningful difference.
Third, we will look at manufacturing and fabrication. A wood frame is going to be less labor intensive and easier to construct than a metal frame. A metal frame requires specialized equipment for drilling, fastening, cutting and potentially welding. A wood frame requires less specialized tools for fabrication and construction.
Fourth, we will look at longevity and life expectancy. A treated wood frame can last 40 years under the right conditions and a galvanized steel frame can last 70 years under the right conditions (in either case it will outlast the life of the hot tub which is 15-20 years). In a hot tub however, both can prematurely deteriorate especially a steel frame if exposed to salt air or water. Salt air, regular water exposure, heavy moisture, or humidity can cause a steel frame to rust and fail. This is the number one concern when using steel in a hot tub. If there is a leak in the plumbing and chlorinated hot tub water is coming in contact with the frame then its going to cause rusting and deterioration. Additionally, if the bottom steel framework is not sealed and comes in contact with ground water than it will also cause rusting over time.
At the end of the day, the hot tub industry still uses treated wood as the material of choice when building hot tub frames. In fact, many of the players that were pushing metal frames 10 years ago have now gone back to wood. It may be because the cost versus benefit is just not there now that steel frames have been out in the industry for 10 years and the long term effects can be seen.
Below is a list of brands for reference that currently offer steel frame hot tubs or offered them at one point and no longer do. You will see that out of 80 hot tub manufacturers across North America less than 5% of them use steel.
- American Whirlpool Hot Tubs
- Vita Spas
- Tranquility Spas
- Alps Spas
- Master Spas – no longer offering
- Clearwater Spas – no longer offering
- Phoenix Spas – no longer offering (out of business)