For future reference, and educational use I will leave this here.
Originally Posted by Intalleyvision
So I'm convinced to use your method to raise the roof. Could you tell me exactly what you used? It seems like you attached the top of the scaffolding to the roof somehow? Is that correct? And then you just jacked up the scaffolding and therefore the roof?
Yes, I attached the tops of the scaffold frames to the ceiling in the bus. I also added a brace from the bottom of each scaffold frame, back to the ceiling, one 2x4 on each side.
To attach scaffold to ceiling, I first screwed a 8 foot 2x4 flat on the ceiling, spanning 3 ribs. Screws were number 14 3/8th bolt head screws, 2 inches long. I used two screws into each of the 3 ribs the 2x4 spanned.
The top peg of the scaffold would but up to the 2x4 on the ceiling. Under pressure, the top peg will dig into the 2x4 some. This is normal, and will keep the ped from moving.
Now the braces.
Scaffold uses metal braces that attach to pins that stick out from the scaffold frame. There are four half inch pins per scaffold frame. The bottom two pins are the two we are going to use.
Now drill a hole with a 1/2 inch wood drill bit, about 4 inches from the end of a 8 foot 2x4. That hole is what the 1/2 inch pin slides into.
Now swing the other end up to the ceiling, along side of the 2x4 that is screwed to the ceiling. Use some 3 inch deck screws, and screw into the side of the ceiling 2x4.
This creates the triangulation needed to keep the roof from moving front to rear.
The width of the scaffold frames keep the roof from moving side to side. Just be sure to lift both sides evenly.
When screwing up the jacks, I lifted the front 2 inches, then moved to the back. I kept repeating this till I was up 23 inches.
If you use 4 frames vs 2, you can use the metal scaffold braces, and no 2x4 triangulation brace is needed.