vanblah

I am converting a garage into a studio and would like to vault the ceiling.

The current rafters are about 14' and are 2x4s on 16" center. I'm going to sister 2x6s to every rafter.

There are three horizontal joists running the width of the garage ... +/-19' from birdsmouth to birdsmouth ... that sit on the the rafter plate. They are not attached to rafters.

I'd like to remove these joists.

I don't have the roof slope off hand ... but my guess is 12/10 or 12/9.

To vault the ceiling I'd like to (in order of preference):

A: install gusset plates at the ridge that extend 12" on either side of the ridge. These would be 3/4" plywood and would be bolted on. This would give me maximum height.

B: install collar ties on every rafter about 1/3 of the way down from the ridge.

C: install diy scissor trusses on every rafter ... this is the most expensive but seems to be the most sturdy. It's probably overkill.

I could possibly install a ridge beam but this gets expensive. I've put in gluelam before when I removed a load bearing wall at a previous house. The span was only 8' though. The garage is 20' deep.

I'd like to hear some suggestions from carpenters here (if we have any). I'm very much a diy kind of guy. I've done most of the exterior work on this garage already (rebuilt one wall due to termite damage and added another).

If you need more information I'll provide it.

I'm in Memphis, so there's never much snow, but we could get a foot every once in a while.