When outfitting cabins, especially rental units, lodges, or frequently used guest housing, showers get heavy, repeated wear and tear. In that environment, what seems like a cost-saver up front can become a recurring maintenance problem. In our research, we found most factory-built cabin builders and modular home builders resort to using a one-piece fiberglass shower insert or fiberglass shower pan with a three-piece fiberglass surround.
In talking with clients, campgrounds, rental owners, and ranchers, the shower insert has proven to be a costly choice, with constant repairs and replacements due to cracking and not holding up to the wear in the cabin.
When we started our cabin journey to source cabins for our own ranch, we knew we wanted a long-lasting, quality shower, and chose a cultured marble shower for its durability, low maintenance, and aesthetics. We did not want a travel trailer feel to the ranch cabins.
Below is a comparison of how they perform under the stresses of high use, what failure modes show up, what considerations matter for durability, and why, in many cases, solid surface / cultured marble offers better long-term value — especially with a steel base to avoid base flex or break issues.
Key Failure Modes & Issues Observed with Fiberglass Inserts
Based on contractor reports (including from properties like Jellystone that rent many cabins), the common problems with fiberglass one-piece inserts in heavy use are:
Weight limits, flexing, and structural weakness
Fiberglass pans and inserts are often designed for residential or lower load use. If someone is heavier or if two people lean heavily, the pan can flex between its supporting structures (if the base isn’t rigid or well supported). That flexing contributes to fatigue over time, cracking around corners, or failure around the drain.
Fiberglass inserts may carry modest load ratings (often in the 200–300 lb range in standard specs), while higher-end solid surface pans can support greater loads and last longer — meaning less downtime, fewer repairs, and happier guests.
Cracking and material fatigue under repeated stress
Because fiberglass units are not entirely solid (they may have webbing, hollow portions, or thin shells with resin and fiberglass weave backing), repeated load, shifting of the subfloor, or lack of solid support underneath leads to cracks — either visible or hidden. Once they crack, leaks follow.
Finish degradation: scratches, dulling, and staining
The gel coat or finish of fiberglass is susceptible to abrasion from stone, boots, grit, and cleaning chemicals. Once the surface is scratched, water and soap scum accumulate, making cleaning harder and the cosmetic appearance worse. Harsh or acidic cleaners can also degrade the resin and finish.
Limited longevity in high-use environments
In rental cabins, repeated turnover, heavy-duty cleaning, and multiple users increase wear. What might be acceptable for a private home for years becomes unacceptable in rentals after only months. Replacement cycles tend to be more frequent, with contractors reporting fiberglass units as a main repair item.
Support and installation issues worsen wear
If the floor base isn’t very rigid or if the fiberglass pan isn’t properly supported underneath (mortar bed, framing, bracing), it results in more movement and stress. Over time that causes sealing or caulk failures, cracks, and leaks.
Guest complaints: “Bounce” or flex in the floor pan makes the product feel cheap or shaky, leading to complaints and sometimes safety concerns.
What Cultured Marble / Solid Surface / Cast Polymer Showers Do Better
Cultured marble and solid surface (resin plus stone dust or synthetic fillers) products address many of those failure modes — especially when other system elements (base, installation) are done correctly. Key advantages include:
More rigid, less flex, better structural stability
Solid surface and cultured marble pans are thicker or more uniformly filled, often with higher-density materials, so they flex less under weight. With a steel base underneath (not wood), there is far less risk of movement, base shift, or sagging. Steel base-built cabins essentially eliminate much of the base flex issue that fiberglass suffers from.
Non-porous, better leak resistance
Cultured marble, properly finished, is non-porous (or nearly so), which prevents water absorption, mildew, mold, and staining. Water can’t seep through small cracks in grout because panels tend to be seamless or have fewer joints. They also rely less on caulk, grout, or silicone at every joint, making maintenance easier and more watertight.
Greater durability under heavy or frequent use
With repeated exposure to moisture, heat, and cleaning chemicals, cultured marble resists many of the factors that wear fiberglass down. Minor chips or cracks are less frequent, and the surface finish holds up longer. Some solid surface trays are rated for higher weight or heavier loading.
Aesthetic and maintenance advantages
Seamless or fewer seams make cleaning easier and reduce mildew, mold, and discoloration. Cultured marble and solid surface materials come in various colors and patterns that mimic natural stone or look more upscale — an aesthetic guests appreciate. They are less prone to staining and easier to maintain with non-abrasive cleaners.
Longer service life, lower lifecycle cost
While the initial cost is higher, the long-term value is greater. Over years of heavy use, fiberglass units often require frequent replacement, repairs, or downtime. Cultured marble and solid surface options typically last 15–25 years in residential settings and significantly longer than fiberglass under similar conditions in rentals.
Trade-Offs & Possible Weaknesses of Cultured Marble / Solid Surface
To be fair, there are drawbacks and considerations, especially in a factory cabin or steel-base context:
- Weight: Cultured marble and solid surface pans are heavier than fiberglass inserts. Handling, shipping, and installation require greater weight capacity. However, our steel base cabins easily handle the extra load without risk of floor failure.
- Damage to finish: Even cultured marble and solid surfaces aren’t immune to scratches or chemical dulling. Heavy impacts can chip the surface. Proper maintenance and non-abrasive cleaners are essential.
- Cost: Higher initial material and manufacturing cost. However, the long-term savings from fewer repairs and replacements often outweigh this.
- Repair difficulty: Minor surface repair is possible, but major damage or failure under the pan can require more involved work compared to swapping a fiberglass insert.
Summary: What Choice Makes Best Sense Long Term in High-Use or Rental Cabin Situations?
Fiberglass one-piece shower inserts have their place — lower cost up front, easier shipping and handling, and faster replacement. But in rental units with heavy usage, their lifespan before major repair or replacement tends to be shorter. If you are buying a factory-built cabin that has a wood base system and floor joists elevated off your foundation, you do not have the ideal support for the insert, which can cause even a good insert to crack and fail over time.
Cultured marble or solid surface / cast polymer showers cost more initially and need careful finish and maintenance, but the trade-off is a significantly longer lifespan, fewer repairs, better resistance to damage, improved appearance over time, fewer customer complaints, and fewer unseen leak problems.
With our steel floor base and floor joists supported by steel I-beams, many of the concerns about using cultured marble are minimized. Even fiberglass shower inserts hold up better with a steel floor system versus a wood floor system.
If you’re considering new cabins for your ranch, campground, or rental property and want a shower that stands up to heavy use while maintaining a high-end look, contact us today to learn more about our steel-based cabins and durable cultured marble shower solutions. Discover how you can combine long-term durability with low maintenance for your property.