Hi guys. So, the time has come – to replace my RV roof membrane, that is.
As we know, the ol’ gal is a ’91, making her 27 years old this year. I’m pretty sure the roof membrane is original, and I’m also pretty sure they’re not supposed to last this long.
Luckily, the former owner(s?) – one being a marine for sure – took very good care of it, resealing any issues they found over their 30k miles of ownership. Unfortunately, that just doesn’t cut it for a super old membrane, and earlier this year after finding a leak near a vent, I decided recoating it wasn’t worth it because of A) the prep work involved (lots of dicor scraping, ugh), B) the lack of peace of mind it would provide, and C) the fact that I really wanted to see what was underneath in case there were more issues I couldn’t spot. Oh, and in case I haven’t said it enough… D) ROOF MEMBRANES DON’T LAST 30 YEARS. 😀
The only downside to this whole process is the labor. Which I could shell out 3-10k for at a shop. But since the materials only cost 3-400, and I’ve got loads of time and want to do it my way and learn throughout the process, I’ll be handling that. Heee heeeeeeee… yes! I’m as crazy as you think!
Now, I will say, if you are confident that your prep work can be effective, a roof coating or liquid roof is probably a better idea as long as the wood decking on your RV roof is completely solid and issue-free. Unfortunately, I already had a roof coating applied from 2016 that has been flaking off (note: don’t use acrylic coatings, ever, unless you only plan on keeping your RV for a year), and on top of that, I see no way to de-chalk the underlying roof membrane to ensure a proper adherance of a new roof coating. Like really. I’ve tried and tried and the membrane, at this point in its life, basically IS a sheet of chalk.
Now here’s what I’ve done so far….
-Removed all accessories
-Stored the AC
-Removed front, back, and side trim pieces (after removing the awning.. don’t ask about that)
-Tried peeling up the membrane
Here’s a timelapse of getting the AC down:
Now, the membrane is STUCK on the roof decking. Like really, really stuck. It would be back breaking work to peel it all up – and, I think this is evidence that the majority of my roof is already in fantastic condition for its age. It doesn’t need any wood replaced. This is an important factor in following along with me, because what I’m going to do CANNOT be done on a roof with decking that has been compromised.
My plan is to cover the existing roof decking with a new layer of luan equivalent (1/4 in plywood), from edge to edge, instead of peeling up the old membrane the rest of the way.
-Again, after a thorough inspection involving pulling up all of the membrane that I can, the roof decking on 90% of the RV is in good condition and doesn’t need replacing. No past issues have caused rot.
-If I peel up all of the membrane, it will be back-breaking work, and it STILL won’t give me the perfect surface required to glue the new membrane to.
-My entire roof is only about 1.5 in thick, so I believe this additional layer will remove my problems/barriers of a properly prepped surface while only adding a nominal amount of weight AND increasing the weatherproofing of my roof, in terms of winter cold and summer heat. Not to mention soundproofing. 🙂
-Another benefit: the way my RV was originally constructd, the side trim pieces are flush with the top of the roof as it is now, meaning that once sealant is added, this turns into a water bowl. Based on what I’ve seen at the grand canyon.. you don’t want to let water’s erosive powers take hold. So by adding even a nominal amount of height to the roof, I’ll be able to solve the water-bowl-problem lickety split without additional construction headaches.
That’s my plan for now… next steps are to get wood. Stay tuned! 🙂