Is RV composite building material a game-changer?

Will Azdel revolutionize the RV industry?

By Andrew Herrick
The alchemists of ages past sought to transmute common, basic elements into that most prized of possessions: gold. (They weren’t much different than today’s crypto miners, those digital chemists bent on transforming 0’s and 1’s into cold cash.)

Anyway, Material Science engineers of the modern era have accomplished something similar. Weaving together the humble elements of polypropylene and fiberglass, a company called Hanwha Azdel has created a unique construction sheet material: Azdel. And Azdel in RVs has taken the industry by storm.

If you haven’t heard of it, just turn around … It might be listening in your walls.

Let’s shake hands with Azdel

Before you meet Azdel, you need to become acquainted with its predecessor, lauan plywood.

Lauan plywood was the commodity plywood of choice for the RV industry for decades. It was used as the substrate for exterior fiberglass, interior wall coverings, ceiling panels, and interior partitions. It was the sub-epidermal layer that bound your RV together.

Unfortunately, lauan is susceptible to rot, mildew, delamination, disintegration, and the other problems that plague engineered woods. The industry-wide delamination failures of the late 20th century permanently stained the plywood’s reputation.

Enter: Azdel.

Originally designed for automotive manufacturing, it snuck into the RV industry back in 2006. Some enterprising RV manufacturers realized that thin, lightweight, waterproof composite sheets like Azdel might just make the perfect substrate for laminated assemblies. And if/when the RV leaked, the composites wouldn’t surrender at the first sign of attack. And guess what? It worked!

It worked so well, in fact, that Hanwha changed its name to Hanwha Azdel and launched an inclusion marketing campaign called “Azdel Onboard.” The company maintains a who’s who list of major RV manufacturers utilizing Azdel in RV construction.

Four myths about Azdel in RV construction

I should interrupt this regularly scheduled program to make a confession:

I like Azdel. I like it a lot. I think it’s the material of choice to use as a substrate for exterior fiberglass and ceiling panels. I’m kind of a fangirl about it.

But nothing ruins a good thing like over-promising and under-delivering. I want you, the RV owner, to be an educated buyer. Azdel is a wonderful product, but it’s not alchemy.

So let’s dig through a few myths about this wonderful material so you know exactly what you’re paying for.

Myth 1: The walls won’t delaminate

Ever hear the joke about the panda that eats shoots and leaves? Choose your words carefully!

Not to split hairs, but Azdel the material won’t delaminate. It’s not a layered product; it’s woven, like a mat.

But laminated walls made with Azdel can still delaminate! Glue bonds between layers can still fail. Or if the lamination plant has a problem with its pinch roller, the individual wall layers can still separate.

Conclusion: In my experience, walls made with Azdel are far less likely to delaminate in the event of a leak. Whereas plywood swells and eventually disintegrates, Azdel is virtually unimpacted by leaks.

(Semi-) Myth 2: Azdel will cut your energy costs

I call this a semi-myth because it’s not technically incorrect (sorry for the double negative).

Yes, Azdel claims about twice the R-value of wood. And wood has an R-value of around R-1/inch.

But Hanwha goes further and says this will “decrease heating and cooling costs.”

Eh … I doubt that. You’re talking about a layer of material less than 1/8” thick. That’s too thin for almost any material to be an effective insulator.

A 2.7mm layer of Azdel has an R-value of about 0.2. Just compare that to the foam core, usually 1-2 inches thick, with an R-value of around R-4 or R-5/inch.

Conclusion: Azdel might increase the nominal R-value of your wall by 5% or so, but I doubt that’s a significant difference in actual heating and cooling costs. Most RVs are just too drafty. And most of your heat loss is through your windows and roof, anyway!

So can Azdel help even out temperatures throughout different rooms? Somewhat.

But is it going to save you boo-koo bucks in propane or electricity? Not likely.

(Semi-) Myth 3: Azdel increases your fuel efficiency

This myth also comes courtesy of the Hanwha marketing team. And again, it’s technically correct … less weight = less power to transport = less fuel consumed.

But how much weight can Azdel save you? Is it significant?

Let’s do a little back-of-the-envelope math. I promise it won’t take long!

If a 32-foot-long, 96-inch-wide travel trailer uses 2.7mm Azdel composite panels instead of 3mm lauan plywood for its exterior fiberglass substrate, interior wall covering backer, and roof panels, how much weight will it save??

(Am I the only one getting flashbacks of high school algebra? If two trains leave Denver and San Diego at the same time, one traveling 87 mph …)

Anyway, go ahead. Guess! How much weight will the Azdel save?

(This is like counting the number of marbles in a glass jar.)

And the answer is … about 200 lbs.

Conclusion: Is 200 pounds enough weight on a 32-ft long travel trailer to significantly impact your fuel economy?

Nope.

However, all that Azdel will buy you another 200 pounds of cargo capacity. Personally, I’d take extra storage any day over a 0.1% increase in fuel economy. Even if you don’t take advantage of the extra capacity, you’ve at least reduced stress on your tires and axles.

Myth 4: Azdel anywhere = Azdel everywhere

This myth sprouted out of the weeds of assumption. Many buyers mistakenly assume when an RV has a green “Azdel Onboard” sticker on the sidewall that means the RV is lauan plywood-free.

This is not true. (In fact, it’s very rare to find an RV that is truly wood-free.)

Just because a manufacturer uses Azdel beneath the fiberglass doesn’t guarantee they’re using Azdel beneath the wallpaper. Or in the ceiling panels. Or in the partition walls. Or anywhere else that lauan plywood is the norm.

And if you’re looking for wood-free construction … then what about the OSB plywood decking? Or the wooden subfloor frame? Or the particleboard cabinet frames? Or wrapped MDF countertops? …. That’s a lot of wood and sawdust!

Conclusion: You should explicitly ask where Azdel is being used. Don’t assume! (And don’t assume the salesperson knows, either.)

Takeaway: Do the myths outweigh the facts?

So, some of the finer points about Azdel in RVs are a bit … overblown.

But I’m happy to report that, in my experience, Azdel does what it says. It’s lightweight. It’s formaldehyde-free. It doesn’t absorb water or delaminate. It doesn’t easily stain or warp. And those are plenty enough reasons for me to use it!

Here’s a promotional video about Azdel Onboard.

##RVT1166