Goostoff wrote:
My trailer is getting some age on it and has never had any roof maintenance done so I think it is time to get it done. I had a vent start leaking on our last camping trip so I figured why not just do everything.
First question it what is the best way to remove all the old calk around all the vents and stuff.
second...about how many tubes of goop will I need. Its a 35 foot 5th wheel with single AC unit, 3 powered vents, sky light, and 3 plumbing vents. I hate to be short half way through the job but also hate to have a bunch of extra sitting around.
I also have the rubber roof paint. Should it be painted before calk or after.
Thanks for any help you can give a guy.
Hi,
On your EPDM roof,
To get the old caulk scraped up, use a heat gun and all dulled up edges stiff blade metal scraper. I use a 1" wide blade, anything much wider and you do not have enough strength to push it. All dulled up, means every edge on that scraper blade is slightly rounded, no sharp edges. Feel it with your hand before using. The heat gun, do not stay in one place, keep it moving to only warm the caulk and not burn the rubber, and the old caulk will scrape up easier. Pending how hot outside it is, it may not take very much heat. At 50F outside, it will take more heat. You will get the feel of it quick how much heat you need. Have the scraper more closer to parallel to the roof as opposed to a 45 degree or higher up angle so you do not dig into the roof. If you want to get back to bare roof and bare moldings, (I recommend doing this) there is a chemical clean step to follow after scraping. Ask for what that is.
A roof that size will take 9 to 10 tubes of Dicor self leveling roof sealant caulk.
I cannot stress enough to make sure the roof rubber is clean before putting your new caulk down. The caulk will not bond long term to dirt or mold. Clean before you start scraping the old up.
If your roof on a 2005 camper never had any maintenance done to it, unless it was stored under cover all those years, odds are favorable there is some kind of a leak that needs a repair. Check close, and address each area when you are removing the old caulk.
Before coating or new caulking, look at all your roof plastic, how aged and deteriorated are they? Sky lights, tank vents, fridge vents etc. Consider replacing aged old roof plastic attached to the roof before re-caulking or coating.
Make sure when you caulk, you have good contact to the aluminum moldings, and onto the EPDM. The caulk will shrink as it cures a little and a light coat at the molding, can shrink away from the molding in a year or more and leave an exposed slit water can get in.
And yes, you want to coat over the new caulking after it gases off. It will help keep the sun UV from breaking down the new caulking.
When using coatings or even Eternabond, heads up. Dicor gases off as it cures and the gas has to escape or it will bubble up under what ever you coat put over it. Waiting 3 to 4 weeks for total gas off will make sure this issue does not happen.
Now as to which coating to use? There are a lot of coatings out there and the prices are all over between them. The question comes down to, how long are you going to keep the camper, are there places where ponding water sits after a rain storm, do you have any Eternabond on any of the seams, do you want this coating to last 10 plus years (or the life of the camper) without recoating in between?
If there is any water damage under the EPDM, repair it before coating the roof.
I myself restore old campers and after dealing with the pain of a water damage restore, you do not want to have another roof leak so I go after long life roof coatings. I'm into the high solids silicone coatings that have lots longer warranties on the life of the product, can handle ponding water and do not require frequent re-coating. But they cost more. (Henry 885/887 Trop-i-cool, Crazy Seal, Gaco brands for the DIY'er, RV roof Armor to have it hired out) Before I type a lot on this, it comes down to cost. These high solids silicone coatings cost the most, then a coating you have to re-apply every 3 to 5 years. Again this comes back to, how long are you keeping the camper and is it OK to save $$ and do more re-coats?
Here is a tip I have learned on coatings and I now swear by. Learn how to do an adhesion test to your cleaned roof before any type of coating is used. This test is not hard to do and after the first one you have done, it is a 5 to 10 minute job on a cleaned roof to apply. And after the cure time, it takes less then 5 minutes to read the outcome of the test. Now you know you have a good or bad bond.
You will have to get the exact method from your coating product manufacture and what is their spec to pass the cohesive failure by. This adhesion test is also nicknamed a pull test. You put a layer of a certain thickness on the roof, and then gently embed/place a mesh material of a certain size on top of the coating. Most of the mesh is under the coating, and a tab hangs out uncoated. Top coat with another coat of the material at a certain thickness. Then wait for the cure time the coating manufacture states. Using a fish scale, you pull on the exposed embedded mesh and read the pounds of force to pull the mesh off the roof. The goal is you get a cohesive failure where the mesh pulled apart between the top and bottom layer and the bottom layer is bonded to the roof. And the pull force to failure was equal to or greater then the manufactures ratings.
If your coating manufacture has no such test or data as to what is a good or bad bond to the roof, then consider what your are applying may not last a long time and you are OK with that. That adhesion test is very standard in the building industry for coatings where lots of dollars are at stake if the coating fails. Educate yourself on all this and the warranties before doing a camper roof coating. And make sure the coating is RV rated, the application on a building standing still is different then an RV rolling down the road twisting and flexing.
Also a tip, many coatings will not adhere long term to the top surface of Eternabond tape unless a prior treatment of the E bond is done. The TPO surface is so slick in it's natural state, the bond will not last long term. I'm a firm believer in E bond and it saved may camper long ago. Just understand how to use coatings over the Ebond the day you want to coat over them.
Hope this helps
John
