I saw something interesting inspecting a home yesterday.

[Bob10]

Yes you would have to tear it out to get proper support in but I wouldn't think it would be that much work. Add the framing and put back fire rock golden

[jamesglenn]

I am curious to know how they framed these as well, since there is a framed sheetrock chase inside and a vinyl sided chase outside; it would have been easier to run the framing straight thru the roof and use the one exterior wall.

The chase doesn't weigh so much that the roof truss is just giving out, so I would believe it was a bad flashing/roofing job to begin with and the leaks weakened the wood framing.

I would think the real issue becomes the wood trusses and how badly decayed the top members are with the years of water damage because those pictures do not look to promising.

[Snipe Hunter]

I don't know how they're framed but I don't think the problem is the chimney chase framing. I'm thinking there is a degree of rafter spread in the garage roof system and the chimney chase is tilting because the roof is dropping and the chimney chase is moving with it which is making it pull away from the wall of the living space and tilting. The chimney can't really drop because it's sitting on the slab. The only thing it can do is pull away from the house and tilt. It doesn't have to move much to throw the chimney way off kilter and open up a passage for water at the flashing. I'm not a fan of collar ties being the only horizontal means of support for rafters. 

This isn't the actual structure but it's built the same. 
This is a diagram of rafter spread. It's common in this type of truss construction. The walls are actually moving away from each other in my opinion. I've been thinking pretty hard about this particular inspection and I've since given the customer an addendum. It doesn't tell him what I think is happening. It just says that I suspect structural problems in the garage roof system and I recommended it be evaluated by a structural engineer.

[Bob10]

That type stuff doesn't pass code here.  I would be you need to add more cross bracing and a few boxes of simpson products using the correct fasteners

[Snipe Hunter]

The house was built in '73. I don't know what the code was in '73 and I don't really know what it is now.Keeping in mind that I'm not a code inspector or a structural engineer. I'm just an observer and what I observed is water damage and a crooked chimney. If in fact that it is cause by rafter spread (a simple tape measure would prove out the theory), the entire roof structure will have to be replaced.

[Bob10]

I doubt it would need to be completely tossed but I would agree it the spread needs to be stopped and could probably be taken back out with a bit if jacking