Interesting Leak situation

[Wade]

This is probably old news for many here but it is new to me. During my first real trip, during a steady rain, water started dripping in around my center roof vent.  The first thing I did months ago on acquiring the Toy was to wash the roof and look for leaks.  There was a leak at the over-cab emergency exit roof vent. That leak was at the seam between the roof and the vent. Easy fix and the coach was water tight until the trip.  The leak looked the same and I expected another easy fix.  Unfortunately there was no place that I could see for water to get in around that roof vent. All the seams appear to be water tight.

I have a metal roof with some rubber like paint on it and all seams taped first.  Everything looked to be in good shape and indeed had been.  However, I knew that I wasn't imagining the leak and I knew there was not enough wind and water to have it be coming in over the vent lip.  There had to be a leak.  Looking closer it appears that what happened was that when they put the "rubber" paint on, there were places where the paint bubbled.  This had not been a problem. However, over time, the tops of some of the bubbles wore through and now I have leaks that just happen to end up coming out at the roof vent. Actual leak is a foot or more away.

My plan is to scrub good with TSP or such, wait for a couple of good dry tarp free days, and then re-coat with roof sealant.  In the mean time I guess I'll just have to keep it under a tarp until I can find the dry time. Roof sealant won't be here for a few days.

Any tips or corrections to my plan are welcome.

Thanks,

 

Wade

[jjrbus]

My roof was in great shape and so was what looked like the original factory sealant.  It must have been kept under cover. Within a year the sealant looked pretty bad so I cleaned everything up and resealed, took a bit of time but not a bad job.

After rains I am finding a bit of water on the floor under the fantastic vent.  I am in Florida so we get some torrential downpours.  I inspect but cannot see where the water is coming in or anything that looks like a potential leak. I had to replace the arm on the fan and I also inspect the dome on the Fantastic fan and there is what looks like a scratch, but it is more than a scratch it is a tiny crack.  So with no other culprits in sight I put a bit of sealer on the crack and no more leak!

TSP is a great cleaner but also harsh. It needs to be rinsed off while you are cleaning.  It can actually etch glass, stainless steel and aluminum and damage some paints!  I would try something weaker or be very diligent about rinsing with copious amounts of water as you clean, not after you are done!

[RVdaytrader]

If you have vents with plastic frames they will crack over time and can be hard to see. I had hairline cracks in two of mine. Sealed them up and no more leak.

[Back East Don]

I mainly use simple green up top.  It was suggested by a good friend who had been around RV's for years and said he used it on everything including EPDM.  I tried it and it did a great job and have been using it ever since.  I ended up using liquid EPDM on my roof and wonder if that is the rubbery coating you have.  I had a ton of pin holes and even though I went really thick and heavy up top, the larger holes just sucked the stuff in.  So a thin coat might have not penetrated nearly deep enough to seal and you have a through hole that water is getting into.

If you have not been introduced, allow me.  Dicor lap sealant is sort of the standard for sealing roofs.  For up top use self leveling.  Check out this video for a quick primer on how to use it.  And this one

You should be able to find it at an RV place but if not, Amazon has it.

Wish I got a check from these guys.

Edited August 17, 2016 by Back East Don