Leak Hunting: What was on my roof?

benherman1 · March 04, 2020, 06:08:39 AM

I decided to start hunting down the leaks in my roof yesterday since it was pretty windy outside but still warm enough the bus wasn't a freezer. After peeling down what I thought was the original ceiling then the original ceiling that it was installed over I found a perfect circle of holes in my roof. It looks like someone made a very half baked attempt at sealing these holes after removing whatever was up there. The cable has two wires that are terminated at spade ends on the other side. I'll be properly sealing the holes and drying out then painting the metal. Any idea what this was on the roof?

edvanland · March 04, 2020, 08:28:13 AM

Probably some kind of TV antenna.

freds · March 04, 2020, 08:36:28 AM

Previous owners the root of all evil LOL!

PS. I hope that the next owner is not cussing me out(grin)...

benherman1 · March 04, 2020, 10:04:21 AM

At least the good news is now that I know there are two layers of ceiling I can stand up straight if I redo it with just one layer and proper insulation above it. I also plan to put one of the "heat blocking" sealants on the roof to help out. I like to keep cool when I can so I'm hoping this will help out.

buswarrior · March 04, 2020, 11:32:28 AM

Moving forward, it will be rare to get a bus without various holes punched through the roof for communications and tracking gear.

Vhf radio, cell radio, gps antennae, wifi antennae, satelite tv tracking antennae, electronic log book jazz...

Some buses will see 3 or 4 generations of stuff screwed to the roof, and associated screw holes inside the overhead bins/beside the driver/on the dashboard where the rest of the equipment was installed. Beware of finding the poorly terminated former power cords for all this stuff. Nobody takes care ripping out, they only sometimes take care installing, to prevent call-backs...

Happy coaching!
Buswarrior

DoubleEagle · March 04, 2020, 12:28:56 PM

And, be very thorough inspecting the roof for all such holes, including loose rivets. Just one 1/8" hole can pass gallons of water down into your finished interior causing rot and fungal mold. Repairing the holes can not be done with bondo or cheap caulking, it will take the good stuff from 3M or Sikaflex, or you rivet/bond new sheetmetal over the area. Everything you use should be paintable.

Nova Eona · March 04, 2020, 03:08:40 PM

Quote from: DoubleEagle on March 04, 2020, 12:28:56 PM
And, be very thorough inspecting the roof for all such holes, including loose rivets. Just one 1/8" hole can pass gallons of water down into your finished interior causing rot and fungal mold. Repairing the holes can not be done with bondo or cheap caulking, it will take the good stuff from 3M or Sikaflex, or you rivet/bond new sheetmetal over the area. Everything you use should be paintable.

I've actually been wondering this lately myself - what is the best material and practice when it comes to filling and sealing small holes in aluminum siding and roofing?

DoubleEagle · March 04, 2020, 08:42:27 PM

Quote from: Nova Eona on March 04, 2020, 03:08:40 PM
I've actually been wondering this lately myself - what is the best material and practice when it comes to filling and sealing small holes in aluminum siding and roofing?

That will be a matter of opinion, of which there is no shortage here, but I would use shavehead rivets with a little Sikaflex to seal it well. It all depends on the size of the hole and how many are within the area. Here is a marine products site that sells Sikaflex: https://www.jamestowndistributors.com/userportal/document.do?docId=1007 There are many other suppliers, so check around. Sikaflex is quite often used to bond the sheet metal on the side of the conversions, and will hold as good as rivets. Check the archives here for discussions on which Sikaflex to use; they have many formulations.

chessie4905 · March 05, 2020, 04:15:28 AM

Also consider Flexseal. That stuff is awesome. Much tougher than silicone.

buswarrior · March 05, 2020, 05:34:33 AM

Don't use a silicone caulk, unless you want paint or anything else to never stick again, have to redo it over and over...

Damned marketers... silicone has its uses, but it makes a lot of trouble.

Happy coaching!
Buswarrior

benherman1 · March 05, 2020, 07:44:06 AM

My current plan is to drill the holes out just a bit to get the ripped areas out then put a short stainless bolt through with a large washer above and below with a bit of sealant to keep things dry.

In other news I worked my way father back on pulling the ceiling last night and found the AC was installed so badly the whole front half wasn't even clamped down. It will be removed and replaced with a patch. The bus already has floor ducts for the heater so the obvious solution is to install AC there.

peterbylt · March 06, 2020, 10:47:25 AM

When I was first tearing out the original ceiling I discovered that over the years, whenever they needed a new antenna, they just drilled a hole and put in a new antenna leaving the old base.

I discovered 13 antenna bases.

After removing all the bases I had 13 aluminum patches cut, using my sander I ground everything smooth and glued in the patches with Sikaflex 252, no leaks in 3 years.

Peter

dtcerrato · March 06, 2020, 10:52:40 AM

It appears that all those "old mounts" may have been some kind of an antenna array where all of them may have been utilized at one time.

benherman1 · March 06, 2020, 11:48:40 AM

I thought my three antennas was bad... As far as patch material goes I found out my local scrapyard had a nice pile of never used stainless sheet metal so I bought a piece to patch with. Is it ok to wire wheel the old paint off or should I be using a solvent?