We've been sitting on the same kind of crapper for centuries. Sure, the plumbing has gotten more tucked away and seats are now fashioned out of all sorts of materials and styles (including plush vinyl embroidered with cats), but as far as the toilets themselves go, hundreds of years after they were invented, they're still largely porcelain.
But why? Isn't there some fancy new material that's better at holding up to our modern gustatory preferences?
A toilet needs to do three things well, according to Brian Hedlund, Kohler's senior product manager for toilets. First, "It needs to be a flushing engine." Next, he says, "It needs to be water-proof, clean, and sanitary." Finally, explains Kohler's king of thrones, "it needs to be sturdy." Because people sit on it. Some of those people will be quite heavy. Porcelain, as it turns out, aces at all three of these requirements.
Most important to the user is that the toilet be an effective, ahem, waste remover. But what looks to most of us like some water swirling down a hole to who-knows-where is actually a machine with a pretty complicated design. "The tank, bowl, jetway, trapway -- it's highly detailed," says Hedlund. "There's a lot of intricate engineering." Vitreous china toilets (what we call porcelain) are made from clay and water. The manufacturing process, which includes being poured into a mould, finished, glazed, and then sent through a kiln, is pretty straightforward and fairly inexpensive.
Plastic, on the other hand, is formed into objects via extrusion or injection moulding. For a structure as complicated as the toilet, plastic manufacturing is prohibitively expensive. That's why plastic's presence on the throne is typically confined to the seat; it's just too expensive to have a leading role.
Another factor is durability. Let's face it, we've all needed to haul arse to the toilet -- and when that happens, the thing better damn sure not give way beneath us. Vitreous china is super-strong and highly rigid. Plastic, though, has some give. While it likely won't buckle under the weight of a hard landing, it certainly might feel that way, and the way it feels matters to users.
OK, so maybe plastic isn't practical. What about stainless steel? It's strong and easy to manufacture. Hell, they have steel toilets in jail, right... The problem, it seems, is user experience. While stainless steel is super sturdy, it's also really sensitive to temperature changes. In other words, it will freeze your arse. Topping it with a plastic or wood seat just doesn't look right, and prison chic doesn't go very far in the average home.
Porcelain is also a champ at shrugging off water. It may sound simple, but a porous material will allow liquid and bacteria in, so being impervious to both is important in a structure that's main job is to deal with waste. The key to keeping water out is in the porcelain's glaze. After the toilet is coated, it's fired in a kiln. Unlike, say, grout in a shower, which takes on both water and bacteria, the glaze stops bacteria at the toilet's surface.
Having all the gross stuff remain on the toilet's surface also makes it easier to clean. (Imagine if cleaning the toilet were any less pleasant.) And every year another wave of aggressive cleaning products claim to do better work on the bowl. In order to ensure that the toilet can withstand the pressure from both abrasion and chemicals, Kohler sends their cans through the equivalent of 20 years of use, or 80,000 scrubs. The testing, Hedlund says, just confirms that people are more likely to upgrade their toilets for water conservation or style reasons than for actual need.
It's amazing the porcelain has remained our number one for so long, especially considering, says Hedlund, that "no one uses the toilet the same way." I'm not really sure what he's talking about, but it makes sense for the man behind the magic to have high standards. In fact, it's very comforting -- a defective toilet is an awful, awful thing.
Rachel Swaby is a freelance writer living in San Francisco.