Based on what everyone is suggesting I see 2 main approaches:
Option 1) Use a multi-tool (Fein or other) that allows me to make wall cut(s) that is/are right up near the ceiling. Keeping the cut(s) near the ceiling should give me very good odds of remaining above the highest wall screws (especially the OSB screws). This should allow the ceiling to drop slightly without having to remove any screws.
Option 2) Use a skill saw and make a cut below the top row of wall screws. Locate the upper row of OSB layer screws beneath the drywall and remove then to allow the upper portion of the wall to shift down slightly before being refastened.Option 1
+ If no drop detected then only opened up thin cut that can be caulked.
+ Don't have to locate and dig out screws under drywall and mud
- Could need more than 2 passes. If drop detected then perhaps make another cut to ensure enough clearance
- Some cuts close to wiring
- Stub OSB not fastened to anythingOption 2
+ Stay away from wiring
+ No stub piece of unfastened OSB
+ If no ceiling drop after screws removed then only lost blade-width on wall
- Have to locate and dig out screws under drywall and mud
Option 1 along beam wall with wiring......
Option 1 along other 3 walls......
Option 2 along other 3 walls.....
I hope I summed up the suggested main approaches fairly closely. I am leaning towards Option 1 mainly because I am unsure how I could locate and remove all those screws buried beneath the drywall and GG as required for Option 2. I looked over my pictures and video of the OSB stage but couldn't see where the screws were located. My main concern about Option 1 was the lack of control over the depth of the cut using a multi-tool and the associated risk of hitting wires beneath the surface. However it looks like Fein (maybe others too) does have some depth stop attachment
that might do the trick. The other concern with Option 1 is the little unfastened OSB stub. For 3 of the walls I expect the wall's top plate will provide backing to prevent the stub from popping out of place. The beam wall won't have that backing but if the stub did tilt out of position then I would expect the wall's drywall layer would also provide the ceiling support.
edit: Oh and Option 3) Do Nothing. Part of me sees this contact with the joist simply as another whisper clip rigid connection between ceiling and joist. I thought I remember Ted saying there is nothing magical about the whisper clips. It's the channel and its flexibility that make this all work. Having the very edge of the ceiling touch the joist does not take away from the flex except at the very end of the channel......but who am I kidding, I doubt I would be able to leave it as-is
Thanks for all the great analysis on this major headache! I haven't ordered any multi-tool yet so if you have any more feedback then please feel free.....Edited by 235 - 6/6/13 at 12:17am