A modern toilet exists as something of a contradiction. By virtue of its function, it’s far from a sanitary item. Yet it’s manufactured to be one of the easiest-to-clean items in a home.
And while toilets are amazingly durable — they can stay in service for a century or more — anyone who’s ever made the mistake of over-tightening a toilet bolt knows the distinctive tink of a cracked toilet base or tank.
Given all this, it’s no surprise so many people wonder what toilets are made of. So I consulted with two toilet-industry insiders, one from a leading manufacturer and another from the pre-eminent testing organization.
About the Experts
John Koeller, an engineer, has been studying toilet performance and water use efficiency since 1993. He co-founded MaP (Maximum Performance), which tested close to 6,000 toilet models from 192 brands since 2002. The company makes all test results free and available to the public.
Ryan Grotegut is the marketing manager for toilets at Kohler Co. He focuses on new product development, ranging from more traditional toilets like the Kohler Highline to the highest end models like the Numi 2.0.
Sources
Pipe Dreams: The Urgent Global Quest to Transform the Toilet, by Chelsea Wald (Simon & Schuster/Avid Reader Press, 2021).
What Is a Toilet Made Of?
Chances are you’ve heard toilets are made of porcelain. But that’s not technically correct.
While Victorian-era toilets were indeed porcelain, by the 1920s manufacturers began switching to vitreous china. Of course, now you’re probably wondering, what is vitreous china?
Without getting too technical, that’s a coating applied to porcelain that makes it smoother and more durable. Vitreous china is the name of the coating and the finished material, the same way toasted bread is simply called “toast.”
Today, residential toilets are almost all made of vitreous china. “All Kohler toilet products are made from vitreous china,” says Grotegut.
Still, most people simply call them porcelain. We’ll use the terms interchangeably here.
Do Toilets Have To Be Porcelain?
Well, no. Before porcelain’s rise in the 1880s, most toilets were wooden. And before that, stone.
If you really wanted to, there’s nothing to stop you from building your own plastic toilet with a 3D printer. (Although, considering the difficulty of cleaning 3D printed objects, it’s probably not a hygienic choice.)
Or maybe your tastes run more ostentatious? A gold-plated toilet will run you from $2,000 to $3,000. Of course, that’s just gold plating over porcelain.
I could only find one functional solid gold toilet, which was valued at around $5,000,000. I say ‘was’ because it was stolen in 2019, and the toilet was likely melted down and resold. (Let’s hope that gold didn’t end up in anyone’s dental fillings.)
Today, it’s not unusual to see outhouses with wooden toilets, while toilets in prisons and airplanes are typically stainless steel. And portable toilets, found at concerts and job sites, are typically plastic. But in the realm of residential toilets, vitreous china is still king.
Why Are Toilets Made of Vitreous China?
It boils down to water resistance, durability and public perception. Let’s look at each:.
- Water resistance: Essential for material that’s continually exposed to water. “Vitreous china has incredible resistance to water absorption,” says Grotegut. “Even plastic has the potential to absorb water in small amounts over time, which is the last thing anyone wants to happen inside a toilet bowl.”
- Durability and strength: Also important for such a frequently-used product. It’s true porcelain toilets can last for years. But the same is true of stainless steel, and we’ve already mentioned porcelain can crack if over-tightened. So that brings us to …
- Public perception: This can override many other factors. For many homeowners, porcelain simply “feels” cleaner and sturdier than other materials. Koeller has seen manufacturers offer lower-cost toilets by using plastic in areas like the tank. But sales never seem to support this move. For Koeller it’s clear: “Americans prefer vitreous china.”
You may notice we didn’t include performance on this list. According to Koeller, two decades of MaP testing shows effective hydraulic design sets toilets apart, in the bowl and the way water moves from the tank into the bowl.
What Are Toilets Coated With?
Porcelain toilets are coated with vitreous china, which can cause confusion, because the toilets themselves are also called vitreous china.
Essentially, a toilet is formed from ceramic clay. During the firing period, it’s subjected to high heat and becomes porcelain. After the toilet is fired in a kiln, it’s treated with vitreous china to make it even smoother and more water and stain resistant.
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