Once you find out that standard stick-built travel trailers are garbage, a natural question comes up: are molded-fiberglass trailers (like Casita, Scamp, Escape, etc.) better than aluminum trailers like Airstream?
"Better" can mean a lot of different things to a lot of different people, so I'm going to talk about it within the context of longevity, durability, and manufacturing quality. Other factors, like luxury and features, are more subjective and up to one's taste. So I'll approach this as if build quality and durability the most important concerns—they are certainly mine.
EarthRoamer
I'm a full-time freelance writer now, but I used to be a mechanical designer. I worked in different industries over the course of my career before ending up at a company called EarthRoamer. If you aren't familiar, they make very expensive, very capable expedition vehicles (basically off-road RVs). While my job was mostly to design the interior cabinetry, I learned a lot about construction standards in the RV industry.
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| Coleman Shasta construction, typical for most of the RV industry |
Most RVs and travel trailers are built like glorified garden sheds. The underlying carriage might be strong steel, but the frame of the "box" is usually just wood. If you're lucky, it might be flimsy aluminum. Some fiberglass insulation will sit between the "studs" and the interior and exterior will get a thin skin of aluminum siding. Other models might use sheets of laminated fiberglass or other composites, but those are still held together by a week frame.
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| An EarthRoamer body |
EarthRoamer was different. The entire "box" was a single molded-fiberglass shell—actually two shells with foam insulation in-between. That is an incredibly sturdy construction method, because there aren't any joints or seams. The walls curve into the ceiling and that provides strength.
Famously, EarthRoamer founder Bill Swails drove a demo truck into a drainage ditch on a remote road in Alaska. The entire truck flipped on its side onto the fiberglass box. If it had been a typical RV, it would have shattered into a million pieces and would have been totaled. But they were able to simply flip the EarthRoamer back on its wheels and kept going. Afterwards, they continued to use that truck for demos for years and all it had was some scratches in the paint.
In contrast, anyone who has owned a conventional RV or travel trailer can tell you that they aren't durable. Just driving normally will it to start falling apart over a few years. Within a decade or two, you either have a pile of scrap or you've spent a lot of time fixing broken cabinets, doors, siding, and so on.
Casita construction
Casita trailers (and other molded-fiberglass brands) are constructed like EarthRoamer. They don't have the sandwiched foam insulation, just a single molded-fiberglass shell with insulation inside. But that outer molded-fiberglass shell is key to their durability. It isn't uncommon to see molded-fiberglass trailers that are 40+ years old and still structurally sound.
Molded-fiberglass is also used for boat hulls, because it holds up to the elements in the long-term and it is very strong. In a conventional trailer, water is always a danger. Even a small leak (which can happen easily thanks to all the joints and seams) can cause wood to rot. That's a serious problem when the entire structure of the trailer is wood.
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| An Oliver molded-fiberglass body, similar to Casita construction |
Casita owners don't have to worry about that. Other than cabinets doors (and exposed wood subfloors on the older models), there isn't anything to rot. Fiberglass is virtually immune to the elements. Its paint might fade in the sun, but it will remain structurally sound unless you physically punch a hole in it.
That is why molded-fiberglass trailers are so desirable. For those of us who have dealt with the inferior construction of conventional trailers, is is a relief knowing that our Casitas are going to hold up in the long term. Sure, an appliance might fail or a latch might break, but those are replaceable. What is important is that the body and structure will always be strong. That is also why they hold their value so well.
Airstream construction
Of course, Airstream trailers also hold their value very well. Part of the reason for that is their style and popularity, but they are also known for longevity.
Most Airstream trailers are built using an aluminum frame with inner and outer sheet aluminum skin. In-between the aluminum skins is insulation. As with molded-fiberglass, this means that there isn't anything structural that can rot. The riveted aluminum is also very strong and won't rattle apart on rough roads.
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| Airstream trailer construction |
Airstream began making their aluminum trailers in the 1930s and their modern models are pretty similar to what they've been selling for many decades now. It isn't unusual to see an Airstream trailer from the '60s still on the road. That's partly because they're valuable and so people put the time and money into either restoring them or keeping them in good shape, but it also speaks to their durability.
Which is more durable?
This is a hard question to answer and my verdict might be controversial, but I believe that molded-fiberglass is superior.
As noted above, fiberglass is impervious to the elements. That isn't true of aluminum. It won't rust like iron or steel, but aluminum can and does corrode. With protective coatings or frequent polishing, the Airstream trailers will corrode. That probably be severe enough to affect structural integrity, but it will happen.
Aluminum also dents easily. Even relatively new Airstream trailers often have visible dents and dings all over the body. Those are nearly impossible to repair perfectly, so an old Airstream will never look new again unless it gets a new skin. There is a reason that many Airstream trailers have protective covers on the front to prevent dings from kicked-up rocks.
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| The Airstream Nest molded-fiberglass body |
But I think the best evidence for the superiority of molded-fiberglass comes from Airstream itself. In 2016, they purchased the Nest Caravan Company in order to take ownership of their molded-fiberglass trailer design. They began selling the Airstream Nest in 2018, so they clearly recognized the value of molded fiberglass. To be fair, they have since discontinued the Nest model, but that seems to have been for reasons other than durability.
Which should you buy?
Whichever one you like better! That answer may be a cop-out, but it is all I can tell. I believe that molded fiberglass is more durable, but Airstream's aluminum construction is almost as good. That means that you should base your decision on the other factors: price, layout, amenities, style, etc.
Current new Casita prices are around $30-35k, depending on options. The cheapest new Airstream trailer is the Basecamp that starts at $46k, while their most expensive Classic model can cost more than $200k.
But Airstreams are much more luxurious and come with many more features and amenities. Casita trailers are relatively spartan. They have the important stuff, but not much more. For us, that is perfect. Others may want the bells and whistles of an Airstream.
Value retention
Finally, let's touch on value retention. Due to the pandemic, the used market is still pretty crazy. But we can compare how each brand holds their value.
At this time, Casita trailers are actually appreciating in value. Used trailers are selling for more than what their owners purchased them for new—that isn't true for Airstream. Part of the reason for that is the wait time to get a new Casita (around 12-18 months), but that isn't the only factor.
But to get a more accurate comparison, let's look further back.
The average price of a 20-year-old Casita seems to be around $15,000 right now, or roughly half of what a new model costs.
Meanwhile, the average price of a 20-year-old 30ft Airstream Classic (the only model that they sold then and now) seems to be about $40k, which is just 21% of the "starting cost" of the current 30ft Airstream Classic.
This would seem to indicate that Casita trailers hold their value better, which could be a reflection of their durability.
In reality, I don't think those numbers tell the whole story. There are just too many factors and too many differences to compare them 1:1.
Conclusion
Neither is "better." Both Airstream and Casita are fantastic brands that will last many decades while holding their value very well. Both are far better choices than any stick-built conventional travel trailer.
An Airstream will cost more, but you'll get more features and luxury (you also have far more variety in sizes and floor plans). A Casita is much more affordable, but also more utilitarian.
Obviously we chose to go with Casita and we don't regret our decision at all. But I still think Airstream trailers are a great option.