Look at my garage wall to slab...

[pushkins]

Yep, you got it !!
Although I'd add the collar ties to as many rafters that I could regardless of if I used the collar to hang the ceiling joist support or not.

[DKAudio]

Just wanted to give you an update...

I got some lumber and a nailer that shoots 3"X .131" nails.

I then removed all the existing vertical supports that were nailed directly into the rafters (even the ones I already modified). This will allow me to jack up the joists when I get to that point.

I also cut one collar tie and installed it. Since the roof is pitched on all 4 sides the collar ties will have to be many different lengths and installed at different heights (I read that for collar ties to be effective they need to be installed in the upper 1/3 of the rafter height).

By the way, the ridge beam is so short that I can only use it to support 1 joist.

Finally, I used my car jack and a 2X4 to "test raise" a joist. I got it to become perfectly level but I heard some creaking and one loud crack (expected I guess). I just hope it won't pull a ton on the 2X4 rafters, I'm just picturing them giving and splitting/breaking but who knows, it may not even be close, I'm not a structural engineer...

[DKAudio]

I got all the collar ties mounted and used all 2X6’s. I used (3) 3” .131” nails on each end into the rafters. I'm thinking about removing the (2) 2X4's that lay on top of the joists, the ones that you said where just to keep them from deflecting, that would be ok, correct?

As far as the vertical supports go, I was going to attach 1 in the middle of the collar tie like you said you would do. I know you said to use metal tie plates but what if I just nail the support on the face of the collar tie and to the face of the joist (nails would go through the vertical support and sink into the collar tie, same with the joist)?

The one support that I can use the ridge beam for will be perpendicular to the joist. Should I just use rafter ties/hurricane ties to attach it to the joist?

Finally, do you think it would be a good idea to add 2X6 vertical supports in ¼ of the way? I would again cut the top of the support angled to the roof pitch and nail it to the face of the rafter and then nail it to the face of the joist.



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[pushkins]

I got all the collar ties mounted and used all 2X6’s. I used (3) 3” .131” nails on each end into the rafters. I'm thinking about removing the (2) 2X4's that lay on top of the joists, the ones that you said where just to keep them from deflecting, that would be ok, correct?

I'd leave them there your going to cover them anyway with drywall. You can also reset them to the ceiling joists are evenly spaced (24" at the walls and 24" in the center) plus they will help with movement cause by the garage door opener/s

As far as the vertical supports go, I was going to attach 1 in the middle of the collar tie like you said you would do. I know you said to use metal tie plates but what if I just nail the support on the face of the collar tie and to the face of the joist (nails would go through the vertical support and sink into the collar tie, same with the joist)?

Yep, that will work !!

The one support that I can use the ridge beam for will be perpendicular to the joist. Should I just use rafter ties/hurricane ties to attach it to the joist?

Yep, that's about all you could do in this situation without getting too involved.

Finally, do you think it would be a good idea to add 2X6 vertical supports in ¼ of the way? I would again cut the top of the support angled to the roof pitch and nail it to the face of the rafter and then nail it to the face of the joist.

Yes that would also help with the drywall load, the more support you can give it the better. 2x4's would do just as good a job for a little less in cost.

[DKAudio]

I finished this weekend. I added a verticle in the center of every collar tie and also added verticles 1/4 or the way in on each side. I nailed these directly to the rafter.

I leveled all the joists before I attached them, the joists now seem strong, level and ready for drywall.

On another note, I am going to add insulation (kraft faced). I don't want to purchase attic baffles to place between every rafter space, is there something cheaper that I can do? Also, kraft faced insulation provides enough of a vapor barrier, I don't need to add any poly or anything, correct?

[pushkins]

It looks good, glad to hear your making head way.

If the insulation is faced you "do not" want to add any other form of vapor barrier.
As for the baffles they only need to be added where the vents are in the soffit BUT in the other areas you need to make sure the insulation doesn't touch the underside of the roof deck. You can use cardboard as a baffle, cut it to fit hard between the rafters and bend it downward to create and maintain a clear channel.

[DKAudio]

I put up new aluminum soffit last year, it has vents every 8". With a hip roof I would need to add baffles between every rafter space.

Why do you not want the insulation to touch the decking? A piece of cardboard can though?

Thanks!

[pushkins]

When the insulation touches the roof decking it usually doesn't touch in a single spot it ends up touching a broad area and hence blocks off air flow, insulation will also when touching the roof deck absorb massive amounts of any moisture. Cardboard (cheap way out) will absorb moisture but it's contact points would be very small and the air movement would keep them dry, once insulation gets wet it's very difficult to get it dry. The cardboard could be stapled to the underside of the rafters "Baffles are only about a buck a piece".

[DKAudio]

I bought attic baffles for my house (garage is detached) when I was getting new soffit and it was over $100. I will go look at another big box for cheaper ones, if I can get them for $1 I will just buy them.