25' x 32' garage, Can I remove the Joists?

[BeamerGuy]

Here is my situation. I have a 3 car garage that is 32 feet wide and 25 feet deep. It has a gable roof with 2x8 rafters at 12oc. In the center of the roof is 10x2 or 12x2 nailer. The nailer/ridge pole at the bottom is about 6ft higher than the joists so there isn't much slope for the width. The joists are 2x6's at 12oc, 3 sets run across the garage ceiling. Holding them up are doubled-up 2x10's approx 10 feet long and the joints are sitting on 6x6 beams. Since I'm an auto mechanic by day I want to put a lift in my garage but to do so I need 13 feet of clearance to the joists. Right now I have 11 feet. Also, the gable end is where the garage doors are, and where the 32ft width is.
I was planning on just putting in collar ties at the 13 foot mark, to replace all the joists and then I can remove the 2x10's below them and have a big open space for work. I am not entirely confident that collar ties would be sufficient to support the roof so I also thought of putting in enginneered wood beams across the garage from between the garage doors to support the collar ties and take some wieght off the outside walls.
I have been doing some research about this and haven't really found anything about a room this big. Does anyone have an opinion about what could work? Could collar ties alone be sufficient? I live in pennsylvania so snow load must be taken into consideration. Any help would be appreciated, Thanks!

[Don_P]

You lost me in the ceiling joists but they are restraining the outward thrust of the rafters on the walls so they are neccessary. You can typically raise the ties 1/3 of the way up but the rafter size has to be deeper to account for the increased bending force this induces in them. It looks like the rafters were about at their limit as is. That means my fix would probably be more expensive than a call to an engineer.

[BeamerGuy]

Thanks Don,
I am considering installing 2x10x20 collar ties across the rafters. To support them I am planning on using LVL or something similar, depending on price and options, to supoort the collar ties. The pilasters would come down between the garage doors in the front. That would take the load of center of the roof off the outside walls. Any opinions on that idea? Thanks!

[Don_P]

The conventional way would not be to support the rafter ties but to use a beam type ridge. If the ridge can support the roof then there is no spreading thrust, there would not need to be any ties. The ridge support columns would need to rest on large enough footings to bear that load. Another way is a wall down the middle supporting the ridge.

[pbraun]

I'm for sure no expert, although I did recently see a friend's garage about the same size, with 12' ceilings and one bay with a four post lift, and plenty of room. I'll ask him about the construction details.
Meanwhile, just to be sure, why not get some structural engineer to look it over?