Roof Membrane Separating

[Always Learning]

Also, what adhesive would you recommend to secure the membrane? Gorilla glue or some type of RV adhesive?

You might want to start looking for adhesives here.

https://alphallc.us/products/adhesiv...ants-cleaners/

[Riverbug]

Thanks Chad. Biggest concerns are tiny leaks that I can't find and don't show up until the damage has been done. With the current prices of these things, we do plan to hold onto the camper and the truck for the long haul. You, geotex1, and others have provided solid input. I have lots of options and it will all come down to $$ and a personal decision.

I hear you. I've refurbished a few TT now so I understand the issue with leaks - it is inevitable. Our 2022 MLE is the first new RV we ever purchased. Our plan is to take the next year to make sure it's the one we want to keep long term. If it is, we budgeted before buying to take it to RV Roof Install to have a new roof done. By waiting a year we can determine what solar, cell booster antenna, or other accessories we want before we have the roof installed. Best of luck!

[geotex1]

You're exactly right. Not enough coffee - our bourbon for that matter. Kind of like getting a new truck instead of changing the oil.

Couple of questions: would you glue the underlayment to the deck or use screws and glue? Also, what adhesive would you recommend to secure the membrane? Gorilla glue or some type of RV adhesive?

We leave Monday for a five week trip to the Northeast. Not wanting to "hurry up and fix it" I'm going to leave well enough alone until we get back home. I don't want to take the risk of glue not setting up, rain, etc. The roof is secure right now and was fine on a huge trip we took out west back in March.

Thanks so much for reaching out to me. Appreciate your insights.

Yeah, do this repair when you can be stationary for a week at least, and it's always better to do these when there is low humidity (I manufacture commercial TPO roofing systems).

Here are the facts of the matter. The Alpha System's TPO on your rig is applied with a water-based acrylic emulsion - it's all they use with their TPO. I have not seen them sell it in small containers. However, there is nothing special about the formulation other than it is inferior to commercial product as it is designed for lower peel strength to facilitate re-roofing. You can find water-based acrylic emulsion adhesive for TPO of many brands in quart size. Make absolutely sure you use water-based! The super thin TPO for RVs is not compatible with solvent-based adhesive.

Regarding fixing the underlayment to the decking will really depend on what you find. Simple pulled fasteners would be nice, but that's a 50/50 in that the fasteners you are seeing probably have nothing substantial to bite into. The original roof decking is generally a specifically engineered oriented strand board (OSB) for roofing applications (but I cannot tell you how many RV manufacturers do not police the production line because the product has two distinct faces and only one side prepared for proper bonding of membrane!!). Anyway, what often happens when peeling a membrane off the decking is that it'll take chunks and splinters of the OSB with it, particularly along the edges - either completely pulling them off or just freeing it out of the pressed composition. If you find this to be the case under the veneer underlayment and why the fasteners didn't hold, you will need to repair that first in order to have something to fasten to. If it's is a loosened piece, you may be able to inject a good polyurethane-based wood glue to bond it to the rest, but if it's real loose you want to pull that out and proceed to make a leveling repair. FYI - good re-roofs will actually do all these deck repairs before laying the underlayment, but I would not be surprised if an RV dealer did not. I'm going to try my best to explain the trick of the trade here to have such a repair, and you need to use a quick-curing, non-shrinking, two-part, PENETRATING epoxy-filler. This can be found in any quality boating supply house and I have even seen it in the big box stores in recent years.

After inspecting and determining this is the situation you have, you will need to drill 2 to 3 0.25-inch holes in the underlayment above the chunked-out area. Do your best to clean out the recess between the underlayment and decking - shop vac with an edge tool. Tape up everywhere you do not want to get epoxy on, including the underlayment on the side of the seam that is adhered. Mix up the epoxy and force it in under the underlayment in a quantity a bit more than that needed to fill the void. Then press the underlayment down - slowly, and the holes you drilled will eject the excess epoxy. Press the underlayment until flush to the adjacent piece and weight it down with a brick, sandbag or such after you use a putty knife to remove the ejected epoxy from the holes till it is flush with the surface. Let that repair dry for at least 48 hours. Once set, if you have an air stapler, that's best to use to secure the underlayment to the repair because the veneer is so thin (the penetrating epoxy will give you some bonding too). If you do not have one, I suggest you use wafer head screws for the additional bearing area of the large head and being a low-profile head. The screws need not be recessed since you are capping the repair area. The underlayment just needs to be secure.

Should you find that you aren't missing a chunk, but just have edge splitting of the decking such that the underlayment fasteners cannot hold, then bonding with any quality polyurethane based glue will work provided you clean the area of loose material and then apply pressure with the brick, sandbag, etc. till it cures.

[gsmithrr]

Flex armor runs about $180 per foot it is sprayed on over the existing TPO (if feasible) and is about 3/16 of an inch thick

[timlisajax]

Wow - thanks so much for taking the time to walk me through the repair Rob. I did mention that I am on my third roof. The second roof, the dealer failed to install the veneer as directed by GD. Shortly after the install, chunks of the OSB board were evident under the membrane, screws were popping up under the membrane, and staples were getting ready to punch through. So GD paid for another lousy install by the dealer, but at least this time they put down the veneer. Needless to say I am done with this particular dealer.

One of the other posters suggested RV Roof Install if we plan on keeping the camper for a long time. We absolutely love the 337 and the suspension work we've done. I am leaning on the new RV Roof Install roof just to get it right once and for all and for something that will last at least another 10 years. Yep, I know its expensive but I really have no idea what is going on under the membrane that the dealer put on, any pinhole leaks, what else will come loose, etc. And there is a huge value of peace of mind. Lots to think about.

Thank you again for your very detailed response. I am going to do what you suggest when we get home and then make the decision - maybe in the Spring - on a new roof.

BTW - went to school in western PA and really like the drive to Corning through the central part of the state.

[zenasboy]

This thread is just what I was needing to come across. I found the exact same problem on our '18 303RLS a couple of months ago. The decking is coming loose on each side of the bedroom AC and is also pulling the rubber roofing loose. Like timlisajax, my initial though was to just screw straight thru the TPO and then eternabond & dicor the h3!! out of it. Thank you geotex1 for the detailed directions.

Right now I've just been keeping an eye on it watching to see if it gets any worse, but now have a good plan to repair it when that time comes. Will eventually do something like the roof armor but the repair outline above will get us by in the meantime should it become necessary.

[timlisajax]

Flex armor runs about $180 per foot it is sprayed on over the existing TPO (if feasible) and is about 3/16 of an inch thick

Thanks for the info. My concerns with anything sprayed or rolled onto the existing membrane is that there is no assurance that the base OSB, veneer, glue, screws and whatever else is under the membrane is sound and secure. Would hate to drop $5-$6K on a sealant without the assurance the the substructure is in good shape. Just my .02. Others may feel differently.

[timlisajax]

This thread is just what I was needing to come across. I found the exact same problem on our '18 303RLS a couple of months ago. The decking is coming loose on each side of the bedroom AC and is also pulling the rubber roofing loose. Like timlisajax, my initial though was to just screw straight thru the TPO and then eternabond & dicor the h3!! out of it. Thank you geotex1 for the detailed directions.

Right now I've just been keeping an eye on it watching to see if it gets any worse, but now have a good plan to repair it when that time comes. Will eventually do something like the roof armor but the repair outline above will get us by in the meantime should it become necessary.

I received a quote of $5,300 for the roof armor system. That is sight unseen so it would be adjusted upon their physical inspection. Makes sense.

The problem we have is that we have no assurance that the OSB or veneer wouldn't come loose down the road. Also, the roof armor system is applied without removing the AC units and installing new gaskets (according to their video). That may be an upcharge if they offer the new gasket install - don't now.

Totally agree - the info Geotex posted is spot on. When we get back from this trip, I'm going to do the fix he describes and "probably" go the RV Roof Install route. Just having trouble justifying that kind of an expenditure. Yep, the alternative of a hidden water leak could be far more expensive.

[gcjackson77]

I too have a 2018 Reflection 220RK. The roof membrane tore and pulled apart from the front seem. Seems common. GD advertised a 12 year warranty but refused to fix it. Dealer wanted $12000 to replace it. Grand Design warranties are worthless Dealer wanted to sell us a new Grand Design RV with an 18 year roof warranty. Really now! Now days I hear owners referring to their GD RV as the Grand Disaster RV.

[gsmithrr]

I hd flex armor done for about $180 per foot a year ago.

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