The drywall work for sound isolation is a little different than normal practices. Here is the procedure I used.

First off, I used 5/8" rock all around.

For the first layer of drywall, the walls go up first. I maintained a 1/4" gap between all edges (floor, ceiling joists, and other walls. Then the ceiling goes up. As before, there is a 1/4" gap between the all and all other elements (including electrical boxes). Since I wanted to form a solid unit in each wall element and I'm going to be putting up a second layer of drywall, I put this first layer up "backwards", in that the finish side was toward the framing. This way I didn't have to mud the recessed areas. The idea is to have the first layer form a flat base for the second layer.

Once that first layer of drywall was up, I used foam backer rod to fill the gaps so that I wouldn't use as much caulk. Here is a joint between the drywall and the door frame.

Next, all gaps were caulked.

The second layer follows the method of the first, except the good side of the drywall faces out this time. The joints should not overlap the first layer. The one semi-hard part about the second layer was in missing the screws holding the first layer. When screwing into the resilient channel, you have to avoid hitting a stud and "grounding out" the RC. This limits where you can put screws and it is pretty easy to hit the first layer's screws when doing layer #2. Here are some pictures after the second layer is in place and caulking is done.

Next came mudding. Probably one of my least favorite parts of this whole project, excepting the rock wool. Here is the first coat.

This is the second coat of mud.

And here it is after sanding.

Previous: Resilient Channel | Next: First Paint Area