Do not use a 2x4 for a support, the roof will snap those in two if a slight breeze comes, and/or the bus isn't 100% level. The roof will slide and snap them.
The B7 rod is not terribly expensive for what it will do for you. About $42 for 1inch x 4ft length. Times that by 4, and you have a roof raise equipment for $168, + tube and some nuts. So Roughly $200 you can have it raised. Plus $80 in welding materials, $280 and it will be solidified at the hat channels, and another $100 in square tubing for the front and rear fortifications, so $380 roughly you got a roof raise safely. This isn't that expensive, and if you think it is, you shouldn't be building a skoolie. I know a lot of young kids are doing these solutions to live because housing is unaffordable, but regardless you gotta spend a little money on the cheap solutioins too.
This doesn't enclose the roof raise, but for this price you can safely and reliably get it done up and welded together solid.
Hat channel extensions $400-600, and 16-18 gauge sheet panels - $1100-1400.
$200 in rivets.
You're looking at $2700 on the high end, and $2300 on the low end to complete it. Less if you have some of the materials already.
The reason we stress doing it right on these forums is also to help with insuring our buses. Don't be the one who ruins the ability to ensure our buses with insurance companies for the rest of us because you didn't properly secure the roof raise get in an accident, your bus falls apart and the insurance company has to pay out way more than it anticipated because it was weak for all the rest of us. We're all in this together whether you realize it or not, your work affects all of us. It's difficult enough to get insurers to insure our buses as it is.
I watched this method and the only issue I have with this is that you require 4 bottle jacks to lift. vs 4 nuts. $5 nuts vs $220 in bottle jacks, and you still require a slide tube if you look carefully on the video you posted. And the roof is sitting on the bottle jack tops, not welded to it so it potentially could still slide off of the jacks. The guy in the video even stated "The only thing holding this roof up now is gravity" Admitting it was free floating on the jacks. Granted it's sort of locked in by the square tubing in the channels on both sides, but still with enough pressure it could pop out of the hat channel. And with being careful it's not much of a risk.
2 bottle jacks are required, not 4 and besides, you will need at least one for the life of the bus.
What keeps it stable, mich more than the screw method, is the fact that it is sliding within tracks. On my lifts i did 4 “ slider tracks” on each side (38’ bus).
To keep the tubing from popping out, I covered/ secured the square tubes that slide within the hat channels with the 3 inch wide sheetmetal covers that already cover the hat channels on the exterior of the bus. You can use nuts and bolts for that.
This keeps the sliding square tube securely inside the hat channels while you lift.
The upper half of the square tubbing you can either weld or pass a bolt thru to the hat channel.
I used a 4x4 across and thru each window, for and aft, and set a stand in the middle which is where i place the bottle jacks creating a “T” if you will, to raise the roof.
As you raise the roof it will be forced to travel within the encased hat channel.
By using at least 4 sliders on each there is very little to no chance the roof will slide to one side and fall.
The screw method also works but if you are not a good welder there is a chance it could give way. Not only that but with the slider method you already have in place the tubes in place for final securement of the roof.
I’m not saying one method is better than the other but i will say i felt it much safer this way.
Either way you do it “gravity” is your enemy. But with the sliders the only way down will be back in it’s original place, just like when you started versus shifting and falling to one side out of alignment.
With the screw method, if one fails, gravity will send the roof in the direction of the failure vs being forced to go straight down into the hat channels.
I also did not use hat channel extensions. I stead i used a1/4 angle iron and welded it to the square tubing. That was so to create a lip so i could rivet the skins to. I also staggered cut all the hat channels in order to eliminate a shearline.
I did 2 roofs this way and one of them was outdoors. That job , the bus sat outdoors for a week with the roof only being held up with 3 slider tubes on each side.
