I just purchased a 1998 national tropical 36 foot class a motor home... The roof is in good condition and there are no signs of leaks anywhere... I want to do preventative maintenancce BEFORE I have any leaks or problems... I've searched everywhere... What is the type / material of the roof???? I know it's a rubber membrane... What would be the best do it yourself coating to put on the roof ??? I am also going to replace all the plastic covers too... They are pretty britle and I want to be safe.... And while I'm at it I want to seal / caulk all the vents and seams while I am at it... Is there a specific caulk I should use???? Thanks in advance for any help.... Dave
1998 national tropical roof type / material
- Thread starter 1adam-12
- Start date
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Gary RV_Wizard
Site Team
The rubber used in RV roofs is EPDM sheeting that comes either from Dicor or Alpha. You can buy numerous brands of paint-on roof coatings and they all work as long as they are listed as being compatible with EPDM. Most of them recommend the use of a primer as well, but a few types are self-priming.
As for caulk, there is a slight chemical difference between the Dicor and Alpha brands of EPDM roofing, so that the manufacturers recommend using Dicor's lap sealant (caulk) for their roof material (probably 90% of RV roofs) and the alpha brand for Alpha's roofing. I've used both sealants and can't see any difference, but maybe there are some instances where the difference tells.
There is no need to re-coat the EPDM rubber sheeting until it shows signs of wear, meaning you can begin to see the weave of the backing material. Until then, just clean it occasionally to wash away the chalky residue and kill mold. The rubber itself is not what leaks, as long as it remains intact. The preventive maintenance you need to do consists of inspecting all the joint sealant periodically and touch up any areas that look dried out or flaking away.
As for caulk, there is a slight chemical difference between the Dicor and Alpha brands of EPDM roofing, so that the manufacturers recommend using Dicor's lap sealant (caulk) for their roof material (probably 90% of RV roofs) and the alpha brand for Alpha's roofing. I've used both sealants and can't see any difference, but maybe there are some instances where the difference tells.
There is no need to re-coat the EPDM rubber sheeting until it shows signs of wear, meaning you can begin to see the weave of the backing material. Until then, just clean it occasionally to wash away the chalky residue and kill mold. The rubber itself is not what leaks, as long as it remains intact. The preventive maintenance you need to do consists of inspecting all the joint sealant periodically and touch up any areas that look dried out or flaking away.
Gary RV_Wizard
Site Team
I'm glad you brought that up - some folks do get confused about that. TPO is a different roof type than EPDM rubber. While it is a flexible sheet material, it is not usually referred to as "rubber" and, more important, wasn't in use when the OP's 1998 Tropi-cal was built. His is EPDM. TPO still needs caulking (as does fiberglass and metal as well), but is unlikely to ever need recoating. It's a very durable material.
