Newbie roof raise question.

[UpShinnCreek]

Ok, I will admit off the bat that I have never done this. I see and read where folks have cut the roof off to raise it. It provides extra head room which I need. Sometimes, folks raise the windows up, too. This allows for better sight lines when standing in the bus, and more importantly, taller wall space under the windows. I understand why both of these are done and want to do the same.

My real question is why cut and raise the roof as opposed to drilling the rivets that hold the floor to walls and raising the walls and roof together. I am only wanting to raise 6-8". In my mind, there would be a few cuts I would still have to make. I would have to cut around the entry door, no need to make it taller. I have a 71 passenger International Bluebird dog nose. I would like to raise the rear emergency exit so it is taller and extend the door. I would be ok with raising the windshield as well. I just see the dog nose that low anyway. I would have to add more metal at the wheel wells if everything is moving up. By raising the walls with the roof, I also raise the "skirts." Since I don't have any underbody storage, I would be cutting out the skirts to add boxes anyway.
It seems like this would be a simpler solution but know I must be missing something. Why is this a bad idea?

[o1marc]

I still haven't figured out how to transition the front . Seems like a lot more work than the usual method of midwindow cut. Most replace the windows with something different. Here's one issue I see. To raise the whole body you would need to remove the ribs from the floor, really bad idea. Think about the ribs in your thought process.

[o1marc]

The door extension is easy. Just remove the old header and move it up or fab a new one. Sheet metal door extension. I went with double doors for loading ATVs/snowmobiles, etc. I needed the extra 4" headroom to keep from taking my head off riding bikes in.

[musigenesis]

These videos should show you that your conception of how a bus body is built is pretty different from how it's actually built and that your idea of how to raise it won't work very well. This video shows your specific make of bus being built (not in great detail but enough to see how the structure is formed):

https://www.youtube.com/watch?v=-Wx1...irdCorporation

And these two videos go into more detail about how an International bus is built - the construction techniques are nearly identical:

https://www.youtube.com/watch?v=SBcU..._channel=ICBus

https://www.youtube.com/watch?v=YxZB..._channel=ICBus

The ribs of a school bus are not directly attached to the floor in any way. They are attached via tabs and machine screws to the chair rail structure which is itself screwed to the floor; the multiple-bend shape of the chair rail not only secures the outer sides of the seats but also helps ensure that the ribs do not bend inwards as the result of a side impact. The side panels are riveted to the ribs with the skirt portion riveted to triangular brackets screwed to the underside of the body floor.

You might conceivably be able to grind out the screws that attach the chair rails to the floor and remove the rivets that attach the skirts to the underfloor brackets and then lift everything, but you would then have to build a fairly substantial steel-framed wall (equal in height to the height of your raise) to span the created gap between the floor and the bottom of the raised chair rail. The weight of what you're raising would also be substantially greater (probably about 2.5X) than with a traditional raise.

I suppose this would be doable, but definitely not simpler than the standard methods which have been used by many people. If you're an experienced metal fabricator with excellent welding skills, it would probably be fun to watch this being done. If you've never done anything like this before, I think your odds of success would be a lot lower than with a traditional raise.

[UpShinnCreek]

Originally Posted by o1marc

I still haven't figured out how to transition the front . Seems like a lot more work than the usual method of midwindow cut. Most replace the windows with something different. Here's one issue I see. To raise the whole body you would need to remove the ribs from the floor, really bad idea. Think about the ribs in your thought process.

I would have to remove the ribs from the "sockets" that the slip. I would have to weld on an extension. If they won't slip out of the sockets, I can cut them and add in a piece just like is done higher up with a traditional roof raise.

I will be using the original windows and replacing a few with sheet metal.

[UpShinnCreek]

Well it seems like it doesn't matter anymore. Just got insurance and while they will only offer liability and uninsured/underinsured coverage, They will not cover anything with a roof raise. No structural changes.

[Bus'n it]

It's not so much just a roof raise, but any type of conversion. Liability only. You would have to finish the bus and find a private insurer to get anything above liability. Seems as if all insurers have gone this route even if you bought a MCI coach and had it professionally built. I called my insurer NG and they said they no longer offer anything but liability insurance on any type of conversion.

[UpShinnCreek]

Yeah, my policy is through NG, as well. And they required that I insure another vehicle with them as well. Conveniently, my youngest son will get his license next month. I put the vehicle he will drive on there. Hopefully, I won't see an increase in my insurance from USAA on my 5 other vehicles. They all have full coverage and I shudder to think how much they would increase with a new male teenager on the policy. Just liability and uninsured/underinsured coverage cost 50% more than the full coverage I had on the vehicle he will drive.

[thjakits]

As mentioned above - if you are NOT a experienced truck/bus body man - stick with the - by now - traditional way to raise the roof!

Now - IF you are raising the roof - then raise to the max practical!! The work is exactly the same! "I don't need that much storage space!" - no bus converter ever said!!
8" isn't worth the raise!!

You have 3 choices:

- Cut below the windows and raise them...
- Cut above the windows or through the windows and move the upper edge of the windows to keep them low...
- Cut as you wish and close the bus with new sheetmetal - then cut RV windows exactly where you want them!!