Roof insulation

[tomas_maly]

So I stumbled upon this approach to insulating the ceiling from the outside...

http://www.busnut.com/artgm04.html

I'm already 6'2" or so and so I can't touch the inside of the bus, neither the ceiling nor the floor (I can probably insulate the floor from underneath). This insulation on the roof sounds great, but how do you avoid leaking between where the layers of aluminum overlap? Siding on a house is a no-brainer, as each piece above the other overlaps the top of the piece below, so water can't get in the walls. But what do you do on the roof of a bus?

The aluminum isn't fastened across from driver's to passenger's side - only from front of the vehicle to back. This guy says not to fasten it on top when the temperature causes expansion in different seasons - but then how do you prevent gaps that could easily gause water to leak in? I don't see any mention of adhesive where they overlap. I don't imagine there's adequate slope between the layers (which seem to be almost perfectly horizontal) to guarantee water from not leaking in. Maybe I'm missing something.

 

[chev49]

i didnt use the 1 inch sheets, i used the 1/2 in ones, and it works well up to 90 or so temp running only 1 ac. After i add the ceramic beads to the painted roof, and get the solar panels on the roof, i am guessing that i can go up to almost 100 outside temp whilst running only 1 ac.
And i can always add another layer of 1/2 sheets if necessary, but i dont think it will be.
just my experience.

 

[lornaschinske]

So I stumbled upon this approach to insulating the ceiling from the outside...

http://www.busnut.com/artgm04.html...Maybe I'm missing something.

That is not the full article. It is simply a "taste" to give you a little info. If you really want to know, then buy the Notes. George sells them on his Epic Conversion Support website for a mere $2.50. His roof does not leak. I used to post on the same coach forums as him. He would have mentioned it. I also used to subscribe to his Coach Builder Bulletin as well. I believe the back issues are no longer available.

 

[TygerCub]

wow. I remember seeing that back in '09 when I first stumbled on this idea of conversion rather than purchase. Of course, I was thinking about converting a bread truck at the time, but was doing a lot of research non-the-less, and spotted that site.

I did notice that after installing the deck on the bus, the roof in the back stays substantially cooler than the front of the bus. I still have to paint the roof with the solarflex, though, so hope that will change once I get "a-round-tuit". I really, really like his idea better, though and still have ideas about doing it later.

 

[lornaschinske]

... once I get "a-round-tuit"...

There are lots of things I need to do once I get a round tuit. Luckily I have been unable to acquire one.

What I like about George's exterior insulation it that it can be added later fairly easily if it is found to be needed. It's not something we have completely discounted.