How To Tell What Material Your Bathtub Is Made From (And Why It Matters)

There is nothing more relaxing than creating your own spa moment after dealing with the noise and chaos of a long day. The calming sound of the warm water and the chance to unwind can feel like pure bliss. But one thing might put an abrupt end to those peaceful spa nights — not knowing what your bathtub is made of. It might sound odd, but not knowing could cause you to damage your tub without realizing it, since different materials require different cleaners and cleaning methods. A simple test involves tapping the side of your tub: a deep, metallic ring usually means cast iron or porcelain-coated steel, while a dull or hollow thud points to acrylic or fiberglass.

Bathtubs have certainly changed over the years, and so have the materials they're made of. Many early bathtubs were either wood or enamel-coated cast-iron. Of course, heavy cast-iron tubs are still around today, but most modern bathtubs are made from enamel- or porcelain-coated steel, acrylic, or fiberglass. Each material has unique strengths and weaknesses. For example, cast-iron tubs are great for holding heat, but they are heavy and difficult to move. Enamel- and porcelain-coated metal tubs are also prone to chipping, which can be difficult to fix. Modern acrylic and fiberglass bathtubs are lighter, but they are notoriously hard to keep clean, as they are prone to staining and scratching.

A lot can go into choosing the right bathtub style for your bathroom, as well as choosing the material you want it to be made out of. But if you're stuck with the bathtub that was already in place when you bought your home, it's important to know how to care for it to get the most out of the one you have. Besides tapping on your tub, you can also use a magnet to try to determine what it's made of — if the magnet sticks, you most likely have a coated steel or cast-iron tub. Additionally, you can try the press method: you press on the tub with your hand, and if it has a little give or bounce to it, it is most likely acrylic or fiberglass. Once you know the material, you can care for it properly.

With acrylic or fiberglass bathtubs, it's best to use a non-abrasive, non-bleach-based cleaner. One of the best methods to clean an acrylic or fiberglass tub is to mix baking soda, water, and dish soap to make a paste. Spread the mixture around your bathtub and allow it to sit for at least 10 minutes, then gently scrub with a soft sponge or microfiber cloth before rinsing. Weekly preventative cleaning will also help keep soap scum from sticking to your bathtub and make cleaning easier. For enamel-coated tubs, you can use harsher, more traditional cleansers, but you should still avoid very abrasive cleaners and brushes, as they can still scratch or chip the enamel.