Additional support may be needed if the roof is not very stable.
Raising garage roof height.
You could brace the inside of your garage and use hydraulic lifts to raise the roof.
Raising the roof and leaving the walls in place is a little easier but the task of disconnecting the roof from the walls is more difficult than disconnecting the walls from the floor.
Hence i wish to raise the roof by say 9 to 12 inches.
But it is a big roof and expensive to do that for a small return.
There is only two ways to do that.
Approaches to raising the roof.
I know that i could take off the roof add a brick layer and then put roof back on.
A truss framed roof on the other hand doesn t have any attic space to expand you re probably going to have to raise a truss framed roof to get more space.
In the first post it says he wants to raise the ceiling height of the garage.
Consult a contractor for an estimate.
You might also try raising the actual garage itself but this obviously has structural challenges.