How to Tell What Your Bathtub Is Made Of?

Bathtubs serve as the ultimate place for human relaxation, providing both a soothing retreat for the mind and a therapeutic space for recuperation. As an expensive household item, everyone hopes to extend the lifespan of their bathtub through proper maintenance. To do this effectively, it's crucial to understand the material of your bathtub. This article aims to help you identify the material of your bathtub, which is essential for daily maintenance and can also serve as a reference when purchasing a new bathtub. Let's get started!

Visual Inspection

The simplest method is to look for manufacturer documents, labels, or markings. This information may come with the bathtub’s packaging or be found on a label located at the bottom, edge, or near the drain of the bathtub. Labels usually provide important information about the materials used in the construction of the bathtub, such as "enameled steel," "fiberglass-reinforced acrylic," or "cast iron."

If this information is no longer available, you can also determine the material by observing the surface sheen of the bathtub. This mainly involves distinguishing between a glossy finish and a matte finish. A glossy finish reflects light like a mirror and appears very bright. Common materials with a glossy finish include enameled steel, cast iron, ceramic, and acrylic. Matte finishes, which diffuse light and appear duller, are commonly found in fiberglass, solid surface, and stone materials.

Tap Test

Different materials and densities produce different sounds when tapped, making this a simple way to identify the material of your bathtub. Using a coin to tap will yield more pronounced results.

Tapping iron and steel bathtubs usually produce a solid, dull sound, but since these are often coated with an enamel layer, tapping cast iron and steel bathtubs will produce a clear porcelain-like sound. Copper bathtubs, being thinner and less dense, naturally produce a clear sound and may also have some resonance.

In contrast, acrylic and fiberglass bathtubs produce a sound similar to solid plastic when tapped, which is more muted and lacks a clear ring. The difference between the two is that acrylic bathtubs, being hollow, give a distinct hollow sound. Solid surface bathtubs, made from composite materials, have a sound similar to tapping stone and are easily distinguishable.

Touch and Press

This method involves feeling the temperature and elasticity of the bathtub surface. If the surface feels warm and has some give, your bathtub is likely made of acrylic or fiberglass. Other bathtub materials, such as solid surface, ceramic, steel, or cast iron, will not have this effect and will feel hard and cold.

Magnet Test

You can also use a magnet to check if it sticks to the outside of the bathtub. If it does, it indicates the presence of metal in the structure, suggesting that your bathtub might be made of cast iron or steel. Acrylic, fiberglass, and solid surface bathtubs do not contain a metal core, so a magnet will not stick to them. However, keep in mind that copper is a non-magnetic material, so a copper bathtub will not attract a magnet either.

Water Droplet Test

Most bathtub surfaces are non-porous, so water droplets on their surfaces will remain bead-like. However, there are some differences. For example, enameled steel and cast iron bathtubs might leave residues when wiped, whereas water droplets on solid surface bathtubs can be wiped away cleanly without leaving marks. Unlike these non-porous materials, fiberglass bathtubs might have slightly poorer water resistance, and prolonged water exposure might lead to minor seepage, resulting in less effective air drying.


By using the 5 methods provided in this article, you can accurately determine the material of your bathtub, this will help you better repair and maintain it. If you find that the bathtub is damaged beyond repair or wish to replace it with a new one, Giving Tree Home can offer you quality options. Currently, we primarily sell bathtubs made of acrylic and solid surface materials. However, we will continue to expand our range to include more varieties and styles to meet all your needs in the future.

Acrylic Tubs  Solid Surface Tubs