Raise the roof

Blaze

Blaze

The Jeeper Reaper
Joined
Aug 9, 2005
Location
Wake Forest, NC
So I'm thinking about doing some work on the workshop at my house so I can put a lift and add an expansion off of the side. My shop currently sucks as the ceiling is just a smidge under 8. I can't even get my Jeep in there without taking off the antennas. I want to raise the roof up to 12'ish.

I am thinking of taking the roof and separating it from the walls, then calling a house mover to see if they can jack the roof up 4' or so, then I'll come in and add some 4' walls anchored to the existing walls with some anchors and fasteners, then have them drop the roof back down onto my new walls and reattach the roof. In my mind it sounds good, much better than tearing the whole roof off and rebuilding it after extending the walls.

What does everyone think? Anyone ever done something like this? I know I'd seen entire floors of houses jacked up and another floor added below it, so I'm sure it is possible.
 
It absolutely can be done but it comes down to a question of how much $$$ you are willing to put into it. Hell they raised all of the buildings in Chicago
 
Having a wall that's made out of two separate pieces, stacked one on top of the other, is ... gonna be a problem. Wind loads on the building are going to try to buckle the wall where the two segments are joined. It's a big hinge.
 
You could do a cripple wall but like Shawn said, making it resist wind and seismic loads would be the challenge. And, cripple walls are usually at the bottom of the walls and bridge the gap between a wall and a stepped down foundation.

You'd likely be better off jacking walls and roof up all at the same time and installing a 4' tall CMU foundation wall to set your building back on.
 
shawn said:
A cripple wall is braced at the top by the floor structure, then the first floor wall carries up from there.
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Right, which would make doing it on this project difficult to brace against any wind or sisemic loads because it would be above the floor elevation.
 
Futbalfantic said:
On a top crippled wall. Would you not brace that at an angle?
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That would be difficult. The trusses likely aren't designed to support that type of lateral load as currently designed. And you also have to consider if you put an angle brace to the trusses, there would be additional forces transmitted from the trusses through the brace directly to the wall. That new brace would allow transmittal of forces both ways, both resisting deflection from wind loads but also transmitting loads coming from the roof structure, which would likely be a bad thing.

You would need to hire a professional like @shawn or @trailhugger to figure it out for you. :D
 
rockcity said:
That would be difficult. The trusses likely aren't designed to support that type of lateral load as currently designed.
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That is assuming that his roof is made out of trusses. i didnt see where he said they were or not . I dont think that lifting the roof would be a good solution if stick built
 
Most garages are trussed. If his wasn't, modifying the stick built rafter structure would likely be a happy medium with some added supports and collar ties. but even if they weren't trusses, adding braces would still transmit loads to the wall likely unfavorably.
 
Looks like he doubled up 2x4's that went from floor to roof. Wouldn't that help stop the hinge effect?
 
rockcity said:
You would need to hire a professional like @shawn or @trailhugger to figure it out for you. :D
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Assume liability for doing a bunch of hokey shit to an unknown existing structure? Wouldn't touch it with a thirty nine and a half foot pole.
 
My roof is truss built. I was worried about the wind load too at the hinge point, that's kind of why I was asking. Didn't know if there was a way to make that not be a hinge point.

I didn't know if doing that and having a bunch of anchor bolts holding the top plate to the bottom plate along with having wood sheathing on either side would do anything. Probably not especially with a 39' wall. Of course, I could always do like he did and have full length 2x4 up against the existing sections. That would eliminate wind load and really just basically be new walls.
 
Blaze said:
Of course, I could always do like he did and have full length 2x4 up against the existing sections. That would eliminate wind load and really just basically be new walls.
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How does the lateral system work? If you're depending on the exterior sheathing for wall bracing, is the attachment of the full-length sister stud to the partial-length stud sufficient to transfer lateral loads to the sheathing? Are the roof trusses designed to brace the length of the wall, and of sufficient strength to take wind/seismic loads back to the roof diaphragm? Is the roof system capable of taking the additional wind load generated by the added wall height?
 
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