Question about replacing lap sealant on roof.

[{tpc}]

So far, knock on wood, we have not had any problems with leaks. Though I have yet to get the trailer out from storage this year.

At any rate, I am wondering about replacing the lap sealant on the roof. To me, I often use the "if it ain't broke, don't fix it" approach to these types of things, and I am wondering if following that "literally" is the right step here.

Should I go up and try to scrap it all off and replace with new? Or should I look for any cracks or areas where it looks like it might be a problem and just cover those spots? Or maybe remove just problem areas and replace with new?

My fear is that I'm going to end up doing more bad than good if I try to take it all off, but at this point I have yet to inspect it, so I guess I need to see if it needs it first anyways.

Thoughts?

[wiredgeorge]

Try scraping hehe.... NO. Take a tube of self leveling Dicor up on that roof and go over any cracks and seams that may need it. Try to scrape old Dicor is an exercise in futility. You should do this at least once a season. It is pretty hard to scrape a rubber roof (or whatever it is called) anyway.

[chuckster57]

We clean the seam with Fantastik and clean rag. Let it dry and lay a bead right over it.

[JRTJH]

You can go here: https://dicorproducts.com/rudys-downloadable-rv-roof-care-handbook/ and download DICOR's guide to how to maintain your EPDM/TPO roof membrane. Lots of good information and it's easy for the "do-it-yourselfer" to follow.

[{tpc}]

Thanks for the link, very informative. So it seems that I can inspect and add as necessary, or do as chuckster suggested and clean it and lay a bead right over it.

[JRTJH]

I think both are essentially the same thing. You've got to clean it to inspect it properly, and adding sealant to the existing is the same thing as laying a new bead over it (overlaying). So, yeah, both "methods" or "suggestions" are the same thing.

[Jweems]

So far, knock on wood, we have not had any problems with leaks. Though I have yet to get the trailer out from storage this year.

At any rate, I am wondering about replacing the lap sealant on the roof. To me, I often use the "if it ain't broke, don't fix it" approach to these types of things, and I am wondering if following that "literally" is the right step here.

Should I go up and try to scrap it all off and replace with new? Or should I look for any cracks or areas where it looks like it might be a problem and just cover those spots? Or maybe remove just problem areas and replace with new?

My fear is that I'm going to end up doing more bad than good if I try to take it all off, but at this point I have yet to inspect it, so I guess I need to see if it needs it first anyways.

Thoughts?
Most of the information I have seen and my own experience says that you should clean the roof 2-3 times a year. While doing that it is reccomended that you clean off the areas where there is sealant and inspect those closely. If you see cracks, holes, etc cover those areas with reccomended lap sealant. It is best to stay ahead and do this preventative maintenance regularly.

[BrentB]

Or cover it once with Eternabond tape and be done with it!

[ctbruce]

Or cover it once with Eternabond tape and be done with it!As noted in other threads, once Eternabond is down, down... eternally. Ifyo have a problem underneath it that needs fixing, it ain't coming up. Just a word of caution.

[chuckster57]

As noted in other threads, once Eternabond is down, down... eternally. Ifyo have a problem underneath it that needs fixing, it ain't coming up. Just a word of caution.

Yup, and the edges require lap sealant to prevent peeling, so you can’t really “forget it”.

[BrentB]

Yup, and the edges require lap sealant to prevent peeling, so you can’t really “forget it”.

I know you've probably seen more of this stuff than I have, but mine has been on for three years with no peeling.

[Steveo57]

As noted in other threads, once Eternabond is down, down... eternally. Ifyo have a problem underneath it that needs fixing, it ain't coming up. Just a word of caution.But aren't 99% of the problems that you might need to get underneath it caused by water leaks? That's like saying don't build your house properly because it will be hard to take apart if you have a problem. I've never had any issues after eternabonding, but plenty beforehand.

Just my 2¢ worth and no offense intended. I know you guys have seen plenty more issues in your line of work.

[chuckster57]

If for example the screws start backing out where the membrane meets the front/Rear cap, You cant get to the screws to do a proper repair without significant damage to the membrane. OR if you need to do some repair work on the caps and taking off the screw rail is needed.....

a one hour repair can turn into a multi hour full membrane replacement.

[ctbruce]

What he said^^^^x2

[itat]

Do screws in the roof really back out very often when they've got a 1/2" of Dicor and Eternabond tape covering them? And how many backed off screws along a roof seam does it take to become a problem? I'm not trying to be a jerk, I'm just asking what are the chances of this actually being a problem?

If you need to get to a screw that's backing out under the Eternabond tape, can you not just cut the Eternabond where needed, screw down the screw and put another piece of Eternabond over the cut? Or even just put in a new screw next to the one that's backing out and cover it with a new piece of Eternabond tape?

[chuckster57]

I’ve seen screws back out/ break off enough to stand by my original position. And I don’t believe even eternabond recommends tape on tape.

[Steveo57]

I'm glad Keystone saved me some work by installing eternabond on the roof seam of the slide on my new Cougar.

[sourdough]

I'm glad Keystone saved me some work by installing eternabond on the roof seam of the slide on my new Cougar.

Just wait 2-3 years when the edges start coming loose......

[BrentB]

Mine has lasted longer than that with no sign of loosening.

[JRTJH]

Do screws in the roof really back out very often when they've got a 1/2" of Dicor and Eternabond tape covering them? And how many backed off screws along a roof seam does it take to become a problem? I'm not trying to be a jerk, I'm just asking what are the chances of this actually being a problem?

If you need to get to a screw that's backing out under the Eternabond tape, can you not just cut the Eternabond where needed, screw down the screw and put another piece of Eternabond over the cut? Or even just put in a new screw next to the one that's backing out and cover it with a new piece of Eternabond tape?

It's not just the screws under the Eternabond tape that can cause problems. Imagine staples backing out on the 3rd rafter from the front cap. You need to remove the trim extrusion at the front cap and remove the side seam extrusions to roll the TPO membrane back to remove the staples. If there's Eternabond tape, your risk of damaging the membrane increases multifold as does the length of time needed to do the repair. That's only one example of how tape on the front seam can affect a repair further back on the trailer. I can think of many more where you would either be forced to cut the roof membrane or not be able to do a "proper repair" because of the Eternabond.

No, I'm not "against using the stuff" but it has its limitations and using it as a "Band-Aid" to cover the front seam is just one of the "shouldn't be a first choice" over using DICOR sealant and doing the job correctly.

[Whitewolf]

When I uncovered our HC the spring I noticed some spots where the front cap meets the roof that had a few small holes in the Dicor. Mostly where the screw head were at. Grabbed a tube of Lap Sealant and plugged the holes. Now lets go campin'!

I can tell you from me replacing the original tanks vents with Siphon 360 vents that scraping off old LS is a pain in the..........

[JRTJH]

"scraping off old LS is a pain in the.......... "

Yes it is... and scraping off Eternabond microsealant is even more painful....

[itat]

Thanks for the different perspective, guys. If you wouldn’t use the Eternabond on a front/rear seam, where would you use it personally?

BTW, Eternabond doesn’t have a problem putting tape over tape and I’d love to see pics of the edges of the Eternabond actually lifting because that stuff is so sticky I can’t imagine that happening. If you had to use a bead of sealant along the edges, it wouldn’t be worth the investment in the tape IMO because one of the biggest benefits is that you wouldn’t have to worry about touching up the sealant.

[JRTJH]

The only place I use Eternabond is on a cut/gouge in the middle of the EPDM/TPO roof membrane or on the "roof/wall edge" of a slide. On any other location I use DICOR self leveling sealant. The only reason I don't use sealant on the slide edges is because the DICOR won't set up and will stick to the rubber seals when the slide is retracted. DICOR takes years to "completely cure" and will adhere to slide seals 2 or 3 years after application if left in contact for months (as in winter storage).

Here's one example of what I call an "eternabond mess". If you google "eternabond tape failure" you'll get hundreds of pictures of the tape not adhering properly. Not all of them are what I'd call "tape failure". Many are probably failure to clean the surface, applying while the surface is damp or oily, etc. I'm not going out on a limb and say "never use Eternabond". Rather I'd say, don't use it as a "band aid" where you should really be using DICOR the way the factory did, to cover screws, penetrations of the membrane and edges of extrusions. Putting a "permanent seal" over the entire area makes it very difficult, sometimes impossible to repair that area in the future.

[itat]

Thanks. That picture looks like an example of poor prep before applying the Eternabond tape. I agree that it will make a repair more difficult because if the area is prepared properly it should stick very well for a very long time.