Should I use Flex Seal to protect 2-year-old RV’s roof?

Dear Dave,
We are trying to figure out if we need to put a roof coating on our 2-year-old 5th wheel. We were looking at Tropi-Cool or Flex Seal but heard that it forms a hard shell and makes it difficult to make any repairs later, like fixing or replacing gutters. Can you tell me if this is something we should do if there are no current problems on a 2-year-old rig? —Hugh, 2023 Jayco Eagle 321RSTS 5th wheel

Dear Hugh,
According to the Jayco website and the brochure for the 2023 Jayco Eagle, your roof has a patented Magnum Truss™ Roof System. It features a one-piece seamless material that has a 20-year warranty. I went through the brochures, the owner’s manual and several videos, and there was never a reference to the actual roof membrane anywhere. The owner’s manual only recommended cleaning the roof material once a year with a mild detergent, but nothing about a conditioner or sealant.

Since your owner’s manual states to just clean it once a year, I would imagine the material is a newer PVC material that does not need a conditioner. Check your owner’s packet to see if there is an information sheet or brochure on the material such as DiFlex II or Lasalle Bristol.

You still need to check the sealants annually and reseal to prevent moisture penetration. However, I do not feel you need to do anything special since there are no signs of wear or fatigue.

My recommendation for your RV’s roof

Do not use Flex Seal, as this product will get hard and crack prematurely. I am not familiar with Tropi-Cool, however, most of the aftermarket roof treatments should only be applied when the roof material is starting to show signs of wear or tears/separation in the material. At this point I would recommend RV Roof Magic, as I have applied it to a few vehicles that still look new 3 years later.

The challenge with roof material maintenance and conditioning is there are so many types of materials available such as EPDM, TPO, and a bunch of what is classified as PVC. Also, there is usually very little documentation on what material is up there.

To add to the confusion, manufacturers are known to switch materials during production due to supply issues or cost. So the brochures and other documentation just use a generic description, such as with your Jayco model.

Use of EPDM for RV roofs

In the mid- to late-1980s, RV manufacturers started using a rubber membrane, as the previous aluminum skin was only 4’ wide. That required a seam and a potential for leaking, it created a black streak down the sidewall, and then it became very expensive. Many RV manufacturers started using ethylene propylene diene monomer (EPDM), as it was less expensive and much easier to apply due to the flexibility of the material.

However, EPDM has a few maintenance issues as it starts as a black rubber material and the top color is added. So it can break down and cause residue on the sidewalls and deterioration on the roof. It is recommended to clean the roof at least twice a year and condition it with a UV deterrent such as 303 Protectant or Dicor EPDM conditioner. It also expanded and contracted with temperature changes. Therefore, any termination in the material such as roof vents, air conditioners, and all along the edges need to be inspected and resealed, if needed, quite often.

Use of TPO

Then thermoplastic polyolefin (TPO) material was introduced. It expands and contracts less and is manufactured with a single-ply material with the color inherent throughout. You can tell which product you have by removing a roof vent frame and looking at the underside of the extra material. EPDM has black backing and TPO is the same color as the roof. TPO does require cleaning once a year and a conditioner, as well. It also requires a visual inspection of all the sealants and resealing when necessary.

 You might also enjoy this from Dave 

What is your opinion of RV Roof Magic? Does it work?

Dear Dave,
I was wondering if you have ever or could possibly do a non-biased review on RV Roof Magic? It sounds very interesting, but I’m not a big truster of these kinds of products until a non-biased review is done. Thank you! —Don, 2022 Forest River Salem Hemisphere

Read Dave’s answer.

MORE ON RV ROOFS

• DIY resealing an EPDM roof on your RV. If I can do it, so can you!
• How to protect and maintain newly replaced RV roof. Plus, why new roof was needed
• Can you use Flex Seal on an RV roof? If not, then what?
• Which RV roof covering is better, FlexArmor or fiberglass?

Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”

Read more from Dave here. 

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