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Situation: I have a 2.5 car detached garage with a hip roof and 9' ceiling. I'd like to raise the ceiling as much as reasonably possible in order to fit a full lift in it. It looks like these are rafter ties, but they don't look close enough to the rafters to actually be nailed to them. I didn't feel like crawling through all the dirt and insulation to get actual pictures of the connection points.

Can anyone tell me what I'm looking at, exactly?

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Notes: I'm not asking for someone to tell me how to raise it (as in, not asking for structural engineering), but I'd like to gather enough information to determine if this is worth looking into (financially speaking) and to not sound like a complete idiot when describing my situation and goals to a structural engineer over the phone.

I know that 9 feet is at least semi-decent and I could fit a maxjack, but I'd prefer a full traditional 2 post lift to fit trucks/suvs as well. Having to center the lift in the building isn't a big deal as I'd want to center it at a 45 degree angle, anyway, to maximize space around the vehicle.

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    you can very easily send the pictures to the structural engineer
    – jsotola
    Oct 9, 2023 at 0:01
  • A note about 2-post lifts: when figuring how much height you'll get between your floor and the underside of your vehicle, account for the distance between the lifting arms at rest and the lifting points on the vehicle. Unibody SUVs are lifted from hard points on the body that are pretty close to the floor, but pickups or body-on-frame SUVs are lifted from the frame, and those lifting points can be more than a foot off the ground. Even with lift extensions, you lose lifting height. Top of my lift is 4 inches from my 15' ceiling, and I still have to watch where I walk or hit my head.
    – MTA
    Oct 9, 2023 at 1:54
  • @MTA thank you for the reminder that there's never enough room, lol. I'm not vertically gifted, though, so I've been figuring on 6 feet of "body" space plus 5-6 feet for work. I know that's on the liberal end of "enough", but trucks will not be the primary target here - it's mostly for project cars. I just want the ability to do trucks for the occasions I find the need
    – user82600
    Oct 10, 2023 at 7:57

1 Answer 1

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It's a hip roof. You already answered your own question.

Without that central post (or those central posts if there's more than one), a massive part of your roof load would go diagonally down through the hip rafters to the corners of your garage. Rather than sizing the ridge beam, hip rafters, and elements at the corners of your garage to handle all of that load, the designer put a beam across your walls to take some of the load from the ridge beam and transfer that load through bending to the side walls of your garage.

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  • So is this design typical of hip roofs? I guess my question was not what I intended to ask, but I'm primarily just trying to figure out if this can possibly be raised at least 2-3' for minimal cost/effort (as in, not redesigning the entire structure). I am just trying to avoid consulting an engineer if the resulting design is likely to be 20-30k - structural engineers are hard enough to get a hold of without wasting their time XD.
    – user82600
    Oct 8, 2023 at 23:58
  • @iDriveSidewayz, it's not an unusual design. Can you access enough space with that beam and post left as-is? Were it not for that beam I would be uneasy about removing the ceiling, where I would suspect that the ceiling could be fighting non-trivial outward thrust from the rafters. That beam and post put my mind at ease, though. My expectation is that you can delete the ceiling framing. That would remove lateral bracing that could be important to the beam's stability, but fattening the beam until it's close to square if not actually square probably solves any stability issue.
    – popham
    Oct 9, 2023 at 1:03
  • @iDriveSidewayz, dropping a post or posts to the floor from the ridge is another cheap option, although I would worry about a car crashing into such post; bollards would probably be involved, too. The classy fix could involve beefing up the ridge beam, hip rafters, top plate splice connections, and corner studs, where then you could remove the beam and the ceiling. That classy option probably comes with a non-trivial engineering bill in comparison to the other options.
    – popham
    Oct 9, 2023 at 1:05
  • I agree with this answer's description, though a critical point is that it's a hand-framed hip roof. That's a very different animal than a modern engineered truss hip roof. Also, that beam is primarily to support the ceiling. The ridge doesn't need support beyond what the rafters provide if you install rafter ties at your new ceiling height. That said, it's not a simple prospect to raise the ceiling with it in place. You need an engineer.
    – isherwood
    Oct 9, 2023 at 19:10
  • @isherwood, that beam is primarily to support the ceiling? So they just had that extra post laying around the job and didn't want to pay dumping fees? And their disposal method just happened to coincide with a common structural detail?
    – popham
    Oct 9, 2023 at 19:16

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