How to Know If You Have a Fiberglass Shower

It can be challenging to determine whether you have a fiberglass shower or an acrylic shower. The materials look similar, often with a shiny finish. They're both lightweight, making them ideal for second-story bathrooms, and they're easy to clean. There are some subtle differences that can help you to know if you have a fiberglass shower.

Both fiberglass and acrylic tubs use fiberglass in the construction, but the overall process and materials are slightly different. Fiberglass tubs and showers use molded, reinforced plastic to create the shower shape. A layer of gelcoat resin helps reinforce the fiberglass design and gives it some protection.

Acrylic showers are vacuum formed from sheets of acrylic. Fiberglass reinforcement adds to the strength and durability of acrylic showers and tubs. Acrylic is nonporous, whereas fiberglass tubs are porous. Since acrylic is nonporous, it retains heat better than fiberglass when used in tubs. Fiberglass tubs often let bath water cool down quicker because the heat retention is lower.

The first test to tell if you have a fiberglass shower is to press on the material. Acrylic and fiberglass tubs and showers both have a little give to them, so when you press on them, you might be able to feel the slight flexibility. It could also be an enamel-coated steel tub, which won't have the same give and flexibility. You can also hold a magnet to the tub to see if it's metal since the magnet will stick to a metal tub.

Looking at the design of the shower can give you a clue as to whether it's fiberglass or acrylic. Because of the manufacturing process, fiberglass tubs are often more basic with fewer design options. If your tub is simple with little detailing, it could be a fiberglass tub.

Acrylic showers and tubs often come with more custom features molded into the design, such as shelves, seats and other extras. Acrylic also comes in many different colors and textures unlike fiberglass, which is often made in basic white with little texture or decorative detailing. If your shower has lots of detailing, texturing or color, it could be acrylic instead of fiberglass.

Acrylic and fiberglass can both become damaged if you drop something heavy on it. Acrylic tends to be more durable and resists regular signs of wear, including fading, cracking, scratching and chipping.

With a fiberglass tub, you'll often see those signs of wear over time. If you drop something on it, the tub is more likely to crack. You might notice scratches developing on fiberglass tubs from routine use. Acrylic tubs can receive damage over time, but if you're seeing signs of wear or damage, it's more likely a less durable fiberglass tub.

Fading is also very common on fiberglass tubs. You might notice the fading more on the bottom of the tub than the sides. If it looks like there's discoloration between the sides and the bottom of the tub or if there's fading on the shower walls, it's more likely to be a fiberglass tub.

Since fiberglass is a porous material, water can infiltrate the shower every time you use it. That moisture can cause the shower to warp. If you notice your shower surround has changed shape over time or has areas that look misshapen, you could be dealing with fiberglass.