Rubber roof bubbles

[Wally]

went on the roof last weekend to see that there's small bubbles on a small area of the rubber roof. It seems to bu on surface and very smooth. Sombody experience this problem? Is the roof about to leak? It's a 2014 reflection GD 323BHS. See the picture. Thank for help.

[TucsonJim]

Hi Wally,

When Grand Design first started, they used a roofing material called EPDM (ethylene propylene diene monomer). They switched to another material called TPO in mid 2015. So your roof is EPDM. I believe the original supplier to GDRV was Dicor. The roof came with a 12 year warranty which is transferable. However, the warranty states that it doesn't go into effect unless the roof has failed. And by "failed", they mean leaking. In addition, EPDM roofs take quite a bit of maintenance such as regular cleaning, coating and resealing. And for them to honor the warranty, they will most likely require proof of this work being done.

So what is causing the blisters? Typically on an EPDM roof, those kinds of blisters are caused when moisture gets between the roofing material and the sub-roof. As the moisture tries to evaporate, it forms tiny bubbles which cause the adhesive between the roofing material and the sub-roof to separate.

What can you do? Here's how I'd approach it (In no particular order):

1. Thoroughly clean the roof with a rubber roof cleaner, and then coat it with a rubber roof treatment.
2. Do a very detailed inspection on the roof's lap sealant. If there is any lifting, cracking, voids, or hard areas, you'll need to reseal it with lap sealant. Use self leveling on horizontal areas and non-sag on vertical areas. If the existing sealant is in bad shape, remove it first. It it just has minor cracks, then you can coat over it.
3. Thoroughly inspect the inside of the RV for any stains or evidence of water leakage.
4. Contact Dicor to ascertain whether this issue could be covered under the warranty.
5. If needed and the whole roof is questionable, just replace it. Leaks will kill an RV faster than most any other issue.

Jim

[Country Campers]

This may be caused by high moisture inside the RV as well. Lots of cooking , boiling water , long hot showers , with out running a fan or a/c could cause moisture build up inside the RV that could collect on the sealing surface between the roof coating and sub-roof as Jim has mentioned above. It is possible that you do not have a roof leak but a thorough inspection will surely be warranted.

Brian

[BrianCriss]

My question is: since GDRV switched their roofing to TPO, does it require maintenance? If so, what is the recommendation? I have a 2020 Reflection 29RS and prior to this had a class A motorhome with a fiberglass roof that was maintenance free.

[howson]

My question is: since GDRV switched their roofing to TPO, does it require maintenance? If so, what is the recommendation? I have a 2020 Reflection 29RS and prior to this had a class A motorhome with a fiberglass roof that was maintenance free.

Not much different from the EPDM
except you use an alpha aproved roof sealant instead of a dicor sealant

[TucsonJim]

My question is: since GDRV switched their roofing to TPO, does it require maintenance? If so, what is the recommendation? I have a 2020 Reflection 29RS and prior to this had a class A motorhome with a fiberglass roof that was maintenance free.

The TPO roof requires very little maintenance in comparison to the older EPDM roofs. Basically you need to clean it every 3-4 months with soap and a brush. In addition, the seals need to be checked for cracks and resealed if necessary.

Here is a link to the Alpha Systems Roof maintenance sheet. I'd encourage all owners to read this sheet. Then, when you clean and reseal your roof, keep a record for your maintenance log in case there is ever an issue.

https://www.alphallc.us/wp-content/u...structions.pdf

Jim