Dear Dave,
I had a tree fall on my trailer which will require roof and some rafter replacement. The repair company I will be using to replace the roof is a long-time repair/RV manufacturer. They offer a seamless aluminum roof for an additional $300–$400. They claim there will be minimal weight difference between the aluminum and TPO, but with a longer lifetime and higher damage resistance. Do you have any thoughts as to which product might work the best? —Norm, 2019 Grand Design Imagine 2150RB
Dear Norm,
Most RV manufacturers used aluminum for the outer layer of the roof construction for many years, and most changed to rubber or fiberglass in the mid-1980s. While I was at Winnebago, we switched from a two-piece aluminum to fiberglass as it came in a full 8’ wide piece. There were no seams, it was more durable than the EPDM available at the time, and it added to the structural integrity of the roof and other components.
Other manufacturers elected to use the Ethylene Propylene Diene Monomer (EPDM), as it was cheaper and easier to install. There were still a few companies that used aluminum such as Holiday Rambler and Airstream, which is still using it today.
Several different RV roof materials available
Technology has changed and there are several different roof materials available such as TPO and even PVC. These became popular as the EPDM material had a tendency to expand and contract with temperature changes. It also had issues with leaks, and even with the material not sticking to the substructure and peeling off! I have personally witnessed a couple units that had the material wrapped around the windshield.
In my opinion, TPO (Thermoplastic Polyolefin) material has several advantages over aluminum. I spent five years traveling around the country in new units training dealers. The first two years, the product had the two-piece aluminum roof material. The aluminum units were very noisy in heavy rain or hail, and the aluminum looked like a golf ball after a hailstorm with all the dents. A tree branch would also score a line that could not be fixed. Granted, most of this was cosmetic, but still it did not look good. At times it created a puncture or gouge. Those were harder to repair and to keep from leaking later.
When we switched to a fiberglass roof, the noise was slightly lower and there was virtually no damage to the material from hail or branches. I have not had the opportunity to spend as much time in units with a rubber membrane to do a fair comparison. But the few times I did encounter rain it seemed to be much quieter, as the softer material seemed to have a sound-deadening quality. I have not been in a unit with a rubber roof during a hailstorm but have talked with several owners in my seminars that have and did not have damage.
Over the years I have found that any damage to a rubber membrane due to branches or other issues was easily fixed with a tape patch and self-leveling sealant.
Black streaks versus chalking
My biggest complaint with the aluminum roof was the black streaks that would run down the sides of the rig. As the aluminum material is exposed to the sun and moisture, it oxidizes and creates dark streaks that are difficult to clean. Even if the aluminum is painted, it will still oxidize and require cleaning. The rubber membranes will also oxidize and start to break down. However, the result is a white chalky appearance that is much easier to clean.
Longer lifetime and higher damage resistance
I agree that there is probably no weight difference between the two materials, but I question the longer lifetime being an advantage. If properly cleaned and maintained, the TPO material has been proven to last 40-50 years in commercial applications. However, since it has only been used in the RV industry for about 30 years, I think it does have a good track record. On the other hand, there are Airstream trailers that are 50+ years old with the aluminum still in good condition. Therefore, I think you have to look at the longevity of the rest of your RV.
As for damage resistance, I do believe the aluminum is a stronger material than TPO, but I would question what damage it would be more resistant to. Aluminum would not be more resistant to a tree falling on your roof and not only damaging the material but also the substructure. In my opinion, most of the structure of the roof is the substructure, which would be the wood material underneath the outer layer. This could be a thin layer of paneling called luan, which is only about 1/8th inch, or it could be a 3/8-inch particle board.
Which material is better?
Since the aluminum material is $300–$400 more, I would ask the questions of what maintenance is required, what about black steaks, are there more labor costs other than the material, and what is the warranty?
My preference would be TPO, but let’s see what our readers think.
You might also enjoy this from Dave
My RV needs a new roof. What are the pros and cons of PVC vs. TPO?
Dear Dave,
I have to get a new roof on my RV, scheduled for September. The RVgeeks recently did an article on TPO (what I have) and EPDM roofing, describing the pros and cons. My guy wants to use PVC. What are the pros and cons for this roofing material? —Jim, 1999 Fleetwood Discovery 36T
Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”
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My first 5th wheel, an Innsbruck had an aluminum roof, it was great in a drizzle of rain at night with the rain gently pitter pattering. I never experienced a hail storm but did occasionally have heavy rain, not real pleasant. Yes the black streaks were terrible, at least twice a year removal and the longer I left them on the sides the harder to remove. The next one was EPDM, and I didn’t care for the cleaning procedure. Our 2002 Mountain Aire had the fiberglass roof that’s the best for all situations. Easy to clean, inspect, and reseal.
I would ask one more question- roof top safety. How secure is the footing? When in full sun, how hot is one material vs another to have under me?
Absolutely correct Jim. Compared to TPO, the aluminum roof will heat up in the sun and in turn, elevate the interior temperature forcing you to run your A/C unit a lot more on hot days.
I have had all three types and IMO a single fiberglass sheet is #1. I never had issues with TPO or sealants sticking to it and I’d put that in 2nd place. The aluminum roofs I had on my Jayco trailers was just laid down loose & fastened on the edges, so it was very “wrinkly” which wasn’t fun to walk on. It was noisy. I also found that sealants didn’t want to stick as long…perhaps due to a lot of expansion & contraction. It would be my last choice.
ALL roof materials need maintenance and cleaning. Fiberglas and aluminum washed easily. TPO took more work from bird droppings or other stains. My roof is washed several times a year, so they never get too bad.
My 1985 Coachman had an aluminum roof. It was full of tiny holes supposedly caused by acid rain. We replaced it with rubber? The same stuff that flat roofs are covered with. About $350 plus my son in laws and mine free labor. Still on the road.
The holes are called electrolosys which is moisture trapped between the aluminum and substructure and it reacts with the metal similar to a anode rod in water heaters. We had issues with that on sidewall aluminum with Winnebago back in the 1980’s
Dave wow that sure was in depth write up on roof materials & their issues! Actually I’m going to print it out & save it. Out 1965 Utopia trailer had an aluminum roof & it had a terrible under structure & it looked like a wave all over, though it never leaked. I agree with you about TPO material.
Thanks
Happy Veterans Day
Snoopy
Snoopy, Thanks for your Service!
Having had a trailer with aluminum and having worked with aluminum for 25 years this would be my choice today. Not because I love the sound of rain but it’s durability.
there are sealants such as “Sikaflex” that work very well with aluminum.
So in the event that you scratched an opening in it patching with aluminum and gluing it down with Sikaflex which is also an adhesive is very easy to do.
I think that under the rounded (EPDM) edge of our CedarCreek is aluminum already so to glue and seal to it should work.
Dave, your 40-50 year life span on commercial TPO roof is 100% false. An 80 mil TPO won’t make it 50 years and I believe you recommend 40 mil products.
The only way a 40 mil TPO roof makes it 50 years is if it’s parked indoors for 35 of them.
If you are introducing a restoration coating into the equation in an effort to extend the life of a TPO roof, then yes, you can make it last 50 years by applying 25-30 mils of Dicor over it at 10 year intervals.
IMO, a TPO roof is better than aluminum even with spending money on restoration coating to make it last 50 years. It is an absurd assertion that it would make it 50 years without service if its parked outdoors tho.
I think aluminum is cool for the nostalgic look and to be fair, there’s a lot of aluminum roofs still out there on mobile homes and RV’s alike. That said, there’s a lot to be said for current technology. I’m not sure TPO increases durability as much as it decreases O.E.M. assembly costs but it does seem to have a lot of positives, especially from an insulation perspective.
Dave, just to quantify my previous comment, I do not mean to sound insulting but TPO is such a good product it can almost sell itself so making a crazy 50 year lifespan claim as commercial roofing product is unnecessary. I did not mean to come across as insulting but it is such an outlandish claim, it needs some clarification.
I currently own a company with over 100 million feet of roofing under warranty. That’s the equivalent of 334,000, 36 foot RVs. I know something about this. Water heaters, not so much, but roofing, quite a lot.
Your information is always so good and accurate on the roofing topic, I am simply saying that 50 years on a commercial building….. never.
I currently have a 30’ 1989 Holiday Rambler Alumilite travel trailer- original Aluminum roof. Does it have some hail damage? Of course. Would you know it if you walked up to it? No! Would you care if you did climb up and look down on it? I doubt it.
It has a 5’ long crease where a tree limb drug across it. Again, you wouldn’t know it unless you climbed up and looked for it.
We had a 2012 Open Range with a rubber/TPO/PVC?? Roof with big patches where limbs had torn it. Looked way worse than the Aluminum roof on the 1989. BUT once again you’re going to have to climb up and look at it to see it. Who cares what it looks like. In an overhead shot of RV storage is ugly RV roofs! Even new!
1988 Super Chief Aluminum. Still swell, It looks to be one piece to me.
I’m happy with “LUCY’S covering over my head.