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Bought myself a hoist for a belated Christmas present. It is an Auto Lift AL2-11KC-DX. I bought this one because it has a single point safety release and I could picked it up at the Ohio warehouse which is about ten miles East of Summit Racing in Tallmadge Ohio. The $300 I saved in shipping allowed me to buy a more expensive hoist. I installed it in the far left stall. Had to modify the ceiling. Cut attic floor joists out and boxed in the ends and roof trusses.
Very nice. Life becomes a whole lot easier now. This may be the best thing we ever bought. Do I mean the Corvette or the lift? Now what do you think? Ha Ha.
Nice lift, however the method in which you created the extra ceiling space is not good. The ceiling joists you cut are also roof rafter ties that resist horizontal force of the roof rafters. Without the ceiling joists which you cut out in the middle, the roof rafter will now impose a high horizontal force on the top of the bearing walls that has no way of being resisted. The only way to prevent this would have been to install a true structural ridge beam in your lift space, post it down at the gable end wall and reinforce the interior truss or post down to the slab. From the photos that doesn't appear to have been done.
Your gable end wall in the middle where the ceiling was raised where the wall top plates meet the bottom chord of the truss is now a hinge point. The old ceiling acted as a diaphragm to hold this wall from pushing in and out from wind loading. Now the top of the wall plates have no lateral resistance.
I have designed corrective fixes for conditions like this quite often in wood framed structures both new and old along with retro fit lift structural wall and roof modifications to do lift installs similar to this. Load paths in wood framed wall and roof structures are one of the most confusing and misunderstood topics for home owners and contractors alike to properly understand.
Nice lift, however the method in which you created the extra ceiling space is not good. The ceiling joists you cut are also roof rafter ties that resist horizontal force of the roof rafters. Without the ceiling joists which you cut out in the middle, the roof rafter will now impose a high horizontal force on the top of the bearing walls that has no way of being resisted. The only way to prevent this would have been to install a true structural ridge beam in your lift space, post it down at the gable end wall and reinforce the interior truss or post down to the slab. From the photos that doesn't appear to have been done.
Your gable end wall in the middle where the ceiling was raised where the wall top plates meet the bottom chord of the truss is now a hinge point. The old ceiling acted as a diaphragm to hold this wall from pushing in and out from wind loading. Now the top of the wall plates have no lateral resistance.
I have designed corrective fixes for conditions like this quite often in wood framed structures both new and old along with retro fit lift structural wall and roof modifications to do lift installs similar to this. Load paths in wood framed wall and roof structures are one of the most confusing and misunderstood topics for home owners and contractors alike to properly understand.
I agree....i think he could still scab in some chords to make scissors trusses...
I only removed twenty feet of a thirty foot span. Just enough to get my Pickup on the hoist. All trusses and side walls are 2X6 tied together with 5/8 plywood. The wall that is in the chainfall picture is essentially a beam four feet tall, fourteen feet long, and five inches thick. It is not placed in the center but six feet off center. JP
I can see that you don't have a conventional trussed roof, you're essentially hanging the whole thing, including the garage ceiling, from the roof.....
Bill
The ceiling is supported by the white I beam. The post is hidden behind the right hoist upright. You can see the post in the last picture. It is Iron oxide in color.
The ceiling is supported by the white I beam. The post is hidden behind the right hoist upright. You can see the post in the last picture. It is Iron oxide in color.
Please read my post again. You are missing the point that the roof system is now not a tied roof framing system any longer. The bay with the lift has no lateral rafter thrust resistance that was originally resolved by the ceiling joists.
"The bay with the lift has no lateral rafter thrust resistance that was originally resolved by the ceiling joists."
I do understand what you are saying. The walls will be pushed apart by the weight of the roof because the bottom of the trusses which were removed no longer retain the tension forces. What I have done is boxed in and supported the perimeter and set a box that is seven inches thick by fourteen feet wide and fourteen feet long on top. "The roof" JP
And the horizontal thrust is resisted by.......What....
Ah forget it, I know when my professional input isn't wanted any longer.
But you tweaked my interest, Dave.
Removing a 14-foot square section from the joists is a huge bite. He says he boxed-in the hole with seven-inch thick something or other, but what that something is and how it was attached to the joist stubs and/or outer wall is unclear.
What would you have suggested to resist the horizontal loads after (or before) the joists were cut? (perhaps a welded or bolted square of steel beams laid horizontal and supported by the roof rafters, with steel U-brackets bolted to the joist stubs left by the cuts on both ends?)
quite possibly 2x6s (possibly larger....) anchored at the cap plate on the end wall and spanning the length of the sides of the cut area, both on the face of the cut ends of the sides of the opening; and laying flat on top behind the hangers and extending several ceiling joists past the ends of the opening.
the individual plywood pieces MAY be adequate for the vertical load but not the lateral forces....
in other words, box the opening's ceiling joist end face and top to resist the vertical and lateral forces with wood in a similar fashion as you suggested with steel.
Bill
Nice lift, however the method in which you created the extra ceiling space is not good. The ceiling joists you cut are also roof rafter ties that resist horizontal force of the roof rafters. Without the ceiling joists which you cut out in the middle, the roof rafter will now impose a high horizontal force on the top of the bearing walls that has no way of being resisted. The only way to prevent this would have been to install a true structural ridge beam in your lift space, post it down at the gable end wall and reinforce the interior truss or post down to the slab. From the photos that doesn't appear to have been done.
Your gable end wall in the middle where the ceiling was raised where the wall top plates meet the bottom chord of the truss is now a hinge point. The old ceiling acted as a diaphragm to hold this wall from pushing in and out from wind loading. Now the top of the wall plates have no lateral resistance.
I have designed corrective fixes for conditions like this quite often in wood framed structures both new and old along with retro fit lift structural wall and roof modifications to do lift installs similar to this. Load paths in wood framed wall and roof structures are one of the most confusing and misunderstood topics for home owners and contractors alike to properly understand.
Oh good, I'm glad I'm not the only one thinking...that roof has no support now!
the OP's roof is a conventional framed roof, not a truss supported roof; BUT the ceiling joists serve the same purpose in both a truss system and the OP's framed roof: reducing lateral load on the walls. removing them in either instance requires rethinking the integrity of the structure....
When I cut the ceiling of my trussed roof system. I went back to the Engineer who originally designed my roof.
I was able to remove a 12' wide section out of the bottom cord, but only after adding additional struts, and utilizing three sheets of plywood (specifically designed) per truss to transfer the load.
The three sheets of plywood required were cut into specific pieces and nailed off on a nailing pattern which allowed me to then cut out the center.
The only way I can see (with the limited pictures), to repair what the OP has posted, is to double up the top cord of the roof rafter with a rafter that is of adequate size to carry the load as if there were no bottom cords at all. Then it will have to be followed up with collar ties which would obviously result in a loss of ceiling height. But this is a way where you may still get a height tall enough to work under your car.
A structural engineer could help with designing a repair so your roof doesn't cave in and also to keep your walls from bowing out to the outside.
The way I see it, is that if you get any type of a load on that roof, it is subject to complete and full building collapse. And over time, the weight of the roof structure alone will lead to collapse.
And when you do obtain the correct "add on" structural members. You're going to want to ensure that the ridge is perfectly level and straight prior to adding the additional members, and prior to nailing off the gusset plates as will be indicated by the nailing schedule. This may require you to utilize a jacking system from under the ridge, down to the floor.
Save yourself some heartaches and get this completed as soon as possible.
When I cut the ceiling of my trussed roof system. I went back to the Engineer who originally designed my roof.
I was able to remove a 12' wide section out of the bottom cord, but only after adding additional struts, and utilizing three sheets of plywood (specifically designed) per truss to transfer the load.
The three sheets of plywood required were cut into specific pieces and nailed off on a nailing pattern which allowed me to then cut out the center.
The only way I can see (with the limited pictures), to repair what the OP has posted, is to double up the top cord of the roof rafter with a rafter that is of adequate size to carry the load as if there were no bottom cords at all.
A structural engineer could help with designing a repair so your roof doesn't cave in and also to keep your walls from bowing out to the outside.
The way I see it, is that if you get any type of a load on that roof, it is subject to complete and full building collapse. And over time, the weight of the roof structure alone will lead to collapse.
And when you do obtain the correct "add on" structural members. You're going to want to ensure that the ridge is perfectly level and straight prior to adding the additional members, and prior to nailing off the gusset plates as will be indicated by the nailing schedule. This may require you to utilize a jacking system from under the ridge, down to the floor.
Save yourself some heartaches and get this completed as soon as possible.
05-18-2016, 04:19 PM
Finnished Installing My Hoist Today
... and he's got snow load to consider too....