By Alicia, owner of Windows Plus
One of the questions I hear most is some version of “what’s the difference between fiberglass and acrylic, and does it really matter?” It matters more than most people expect. It’s the difference between a tub or shower that still looks good in fifteen years and one that’s chalky, stained and flexing underfoot. Here’s the plain-English version.
Is fiberglass porous?
The fiberglass itself is covered by a thin surface layer called a gel coat, and that gel coat is what you see and touch. When it’s new, it’s fairly smooth. As it wears, it gets rougher and more porous. That’s when you start to see:
- Stains that don’t scrub out, especially around the drain and in corners
- A dull, chalky film that comes back no matter how often you clean
- Hairline cracks and small chips where the gel coat has worn thin
- Mildew that settles into the surface instead of wiping off
So the short answer is yes. Fiberglass becomes more porous with age, and that’s the root of most complaints about it.
What is acrylic, and is it the same as fiberglass?
They’re not the same, even though acrylic tubs and showers are usually reinforced with fiberglass on the back. The difference is the surface. An acrylic unit starts as a solid sheet of acrylic that’s heated and formed into shape. The color goes all the way through, and the surface is non-porous from day one.
If you’ve heard acrylic called “plexiglass,” that’s the same family of material. It’s the same idea: a hard, smooth plastic that holds its finish.
Fiberglass vs. acrylic shower: side by side
- Surface: Fiberglass has a thin gel coat that wears. Acrylic has a thick, solid surface with the color all the way through.
- Stains and mildew: Fiberglass gets harder to clean over time. Acrylic wipes clean because there’s nothing for grime to soak into.
- Scratches: A deep scratch in fiberglass can go through the gel coat. Light scratches in acrylic are far less noticeable, since the color doesn’t change underneath.
- Feel: Thin fiberglass units can flex when you step in. A reinforced acrylic base feels solid.
- Warmth: Acrylic holds heat a little better, so a bath stays warm longer.
- Upfront cost: Fiberglass is cheaper to buy, which is why it’s in so many builder-grade homes. It usually costs more over time because it wears out sooner.
Why we only install acrylic
We install acrylic tubs and showers, not fiberglass. When we tear out a bathroom, the most common thing we find is a builder-grade fiberglass unit that yellowed, cracked near the drain or started to flex. I don’t want to put in something we’d be tearing out again.
We pair the acrylic tub or shower base with grout-free wall panels, so there are no grout lines to stain or reseal. For most homes, the whole job is done in one to two days.
Signs your fiberglass tub or shower is done
- The floor of the shower or tub flexes or creaks when you step on it
- Cracks near the drain or along the corners
- Stains or a chalky film that won’t come clean
- Soft spots or water stains on the ceiling below the bathroom
A flexing base or a crack near the drain can let water get under the unit and into the subfloor, so I wouldn’t wait long on those two. Patches and refinishing kits cover the surface for a while, but they don’t fix a base that’s moving.
What replacing it looks like
We focus on the wet space: the tub or shower, the walls around it, the base, the door and the fixtures. We remove the old unit, check the subfloor, install the new acrylic tub or shower and walls, and leave you with a working bathroom, usually in a day or two. If you’re debating a tub versus a walk-in shower, our shower replacement and bathtub replacement pages walk through both. For budgeting, see our tub-to-shower conversion cost guide.
Want someone to look at yours?
We’ll come out, look at what you have, show you the acrylic options and give you a written price. No pressure, and our own crews do the work. See our current offers or schedule a free in-home estimate.
