QUOTE(euro911 @ Mar 20 2011, 11:05 PM)
I just figured 4.5' for a stock height 914, 4" for the lift rails and another 6" of headroom (3" per car) came up to 118" (+/- 10'), so you're actually not too far off, Tom.
I've seen folks box a small area of the ceiling joists to create a raised ceiling if they needed additional headroom for the roof of a car. That should yield 6" or more inches of additional clearance depending on the height of joists (8~12" depending on the span and when the structure was built).
I haven't seen Andy's garage, yet ...
Mark, it sounds like you're in the building/design biz too!
Another variable is the height of the lift's posts, since they can be taller for units with more than a 4.5' lift, since IIRC some will lift to 6-7' clear under the lift rails, then there's the lift mechanism's override height. So it will be a process of checking various lift mfgr's. specs. for dimensions all around.
I've only seen Andy's place from the street, since he lives about a mile away & in the next complex to one of my son's High School buddies (we're both in Orange). So I can't speak to it's roof structure, but it's a 1970-80's era structure & may have prefab'ed trusses up there, which can actually be restructured at a cost/effort to open up to the rafters. We'll see!
Unfortunately I'm not so lucky with my detached 1921 garage which is only 18' w. x 17.5' d. & about 7.5' h. clr. to the horizontal tie joists below the rafters.
However, I'll need to do some major restructuring to get 3 cars into the garage & resolve roof drainage problems from it's 1920's hacked-up construction methods, since it's attached to a former farm shop building in the rear (my home office now) with an odd high/low/gable/shed/cricket roof setup that I need to rework to extend the main gable back over it, which will require me to raise the roof & insert a 3-4' h. wall section & may carry it back as a truss section over the shop in back to carry the roof & provide lateral resistance (see short side wall @ garage door below). So I may as well set it at what ht. I need.
In the pic below the door is actually only 15' w. (not normal 16') with about 12" of wall/post at each side, and about 7' clr. ht. to the header/beam above, with the rafters inside about 6" above that.
Click to view attachment ... so I need to do some more construction ....