How I repaired the Cavalier FEMA trailer leaky roof

[natemoore]

The problem with this way of installing a roof is that there is no drainage plane for water to make it over the edge of the roof and down the side of the aluminum siding. The rubber membrane should have been cut in such a way as to overlap the aluminum siding on the sides and back, with a fold at the corner. This would have been a good drainage plan. However, the dumb masses at Gulf Stream cut the membrane short at the rear and cut the corner on the membrane. Water has a way of finding its way in, but it generally doesn't defy gravity. The water found its way through the rubber sealant they poured on and the capillary effect took over. To further compound the problem, they installed the vertical aluminum molding up and over the top, which created a dam for water trying to drain off the roof.

http://www.gsowners.com/attachments/photobucket/img_11900_16c6a49d3060c017a58c076124946ff7.jpg

[natemoore]

This is what it looked like underneath.

http://www.gsowners.com/attachments/photobucket/img_11901_3c0d198547882cc645849a41e40564aa.jpg

[natemoore]

I failed to take intermediate pictures, but what I did was remove the top molding entirely, then pull back the horizontal drip channel and vertical corner molding on both sides to allow room to work on the membrane.

I scrubbed everything with mineral spirits to remove residual sticky white rubber and dirt. A plastic putty knife is good for removing caulk from painted surfaces without scratching them.

I used Endurabond, 4" wide, extra thick roof repair tape and the normal 2" wide Endurabond tape.

I used the 4" wide tape to extended the roof membrane down over the aluminum siding in the rear and the sides. I overlapped in the rear by about 1-1/4" and about 2" on the sides. Next, I applied an 8" long strip on the sides, overlapping the first strip by about an inch and over the sides by about 2".

Next, I reinstalled the horizontal drip channel molding and the vertical corner molding, making sure the membrane is flat as possible. However, I did not want to create a dam in the corner like was originally there, so I trimmed about 5" of the top portion of the vertical corner molding such that only about an inch wrapped up over the top.

http://www.gsowners.com/attachments/photobucket/img_11902_a68fdb4c3b2b3f44bbdf99c3e304ca84.jpg

[natemoore]

I reinstalled the top corner molding using only three screws to minimize the number of holes in the membrane. I put ProFlex RV sealant under the molding where the screws were going to be inserted.

This top corner molding could have been left off altogether, but I reinstalled it to hold the rubber down while going 60 mph down the highway.

I still saw all sorts a ways for water to get behind the vertical corner molding, so I ran a 2" wide strip laterally on top of the top corner molding, covering the top of the vertical corner molding and overlapping a little.

http://www.gsowners.com/attachments/photobucket/img_11903_94efdbb1310a2c91818dca0136b0cc88.jpg

[natemoore]

http://www.gsowners.com/attachments/photobucket/img_11904_4fc47816d33e9058f821d4e06c4dd641.jpg

[natemoore]

ProFlex RV sealant is not a silicon, but a solvent based caulk that they claim sticks to anything. I used it to seal the vertical seams between the aluminum siding and the vertical corner molding. If you keep a little bowl of mineral spirits handy, you can dip your finger into it and tool the ProFlex, creating smooth pathways for the water to follow.

The vertical seam is important, but since water wants to obey gravity, it isn't as likely to get in behind the vertical corner molding.

The roof is convex, so water is going to travel down the side of the horizontal corner molding and straight down the side and down the gutter. Note that if I had not trimmed the vertical corner molding where it went up and over the roof, the water would be obstructed on its way off the roof.

http://www.gsowners.com/attachments/photobucket/img_11905_d1f6f3c279a1d27b91f38ae84b5a7a8a.jpg

[natemoore]

Even though the interior looked okay at first glance, it didn't take me long to realize I had roof leaks in both front corners, too. I pulled back the corner molding and pulled up the roof rubber to reveal the black mold growing underneath. Bleach didn't touch this stain, so I just let it dry out in the sun for a couple days.
http://www.gsowners.com/attachments/photobucket/img_12159_3329b394eda2f379d998264f67530007.jpg[/img]

[natemoore]

http://www.gsowners.com/attachments/photobucket/img_12160_226ff09ec1a81189baebec5e471a2970.jpg

[natemoore]

http://www.gsowners.com/attachments/photobucket/img_12161_85d8d629075da44b06cb0330391e0a42.jpg

[natemoore]

I don't like the way the Gulf Stream dumb masses did the aluminum corner molding and drip channel molding. I trimmed about 5" off the channel molding

http://www.gsowners.com/attachments/photobucket/img_12162_42cc29660feab2e2db4b565225b14022.jpg

[natemoore]

And I trimmed about 3" off the corner molding that wraps around on top. Again, just like it did on the rear corners, this molding dams the water instead of allowing it to drain off.

http://www.gsowners.com/attachments/photobucket/img_12163_a03ccc09cca45791ba3ac41a6771ad64.jpg

[natemoore]

The water now can run laterally along the top cap molding and down the side without being dammed up by the corner molding.

http://www.gsowners.com/attachments/photobucket/img_12164_0f7e5c3c73414841cccb630392cc9484.jpg

[natemoore]

The first thing to do is apply the 2" wide endurabond tape to create a drainage plane down the side.

http://www.gsowners.com/attachments/photobucket/img_12166_5e5245277c17e6e54c2ea25dc47d4aaf.jpg

Note how I lapped the roof membrane over the repair tape.

http://www.gsowners.com/attachments/photobucket/img_12166_2a943b4460894aa9ceb8810fd110372e.jpg

[natemoore]

After doing both sides in the previous step, I applied the 4" wide Endurabond tape over the top cap molding all the way across, making sure to overlap the previously applied 2" wide tape on the sides. That drainage plane thing again.

http://www.gsowners.com/attachments/photobucket/img_12168_a7011c53f1ae0155886364a436de4e28.jpg

[natemoore]

Now, I apply a foot long length of the 4" wide tape down the corner molding. I didn't overlap on the outside because I'd have all these unsightly puckers.

http://www.gsowners.com/attachments/photobucket/img_12169_3e8a3036484a5b181ef7873509011b21.jpg

[natemoore]

Another angle

http://www.gsowners.com/attachments/photobucket/img_12171_a81c4ebde3e34cf44e06b82133476f30.jpg

[natemoore]

I didn't like the way this looked. It seemed that water could still get in behind the corner molding through that hole at the rear of the molding (on top).

http://www.gsowners.com/attachments/photobucket/img_12172_d9bc27934fbfb6453a82100570b5b67b.jpg

So, I applied another strip of 2" tape on top of the molding.

http://www.gsowners.com/attachments/photobucket/img_12172_a5267665230a9f948af8375d30f35d37.jpg

[natemoore]

Another view of the finished repair

The last thing I did was to glop on some ProFlex into the lows spots right in front of the top cap molding just to prevent a pool of water from sitting there. This probably wasn't necessary, though.

http://www.gsowners.com/attachments/photobucket/img_12173_75423c6fca35510031c307dac47a5df0.jpg

[natemoore]

After you put everything back together, be sure to caulk the top edge of the drip channel molding and both edges of the corner molding. You can tool the ProFlex caulk with fingers wetted with mineral spirits. Just imagine you're a little water droplet following a drainage plane, not defying gravity, but quick to obey the capillary effect.

[92AginSC]

Nate - Thank you for the excellent write up. I just bought one off of ebay and I suspect I'll need to do the same repairs. Do you know if all the FEMA trailers suffered from these defective roofs?

Thanks again for taking the time to share this information.

Kevin

[northport James]

Wow, I guess I have my work cut out for me. I recently purchased one at a GSA auction. I found out the hard way the MB floor was "squishy" when I walked on it, and seeing your pics & post point me into the right directions. I'll be starting work in the spring. Thanks for the pics.