drywallsound-deadening
So in new construction here…
I want to sound deaden bedroom walls from outside noise. Traffic, storms, loud people, etc. I know I can't achieve 100% due to a window. (I have plans to make a foam insert for that when desired for extra quiet-ness) Ideally I would just do 1/2" drywall – green glue – 1/2" drywall. If I do this, my premade window jambs will be about 1/4" short of reaching the plane of my drywall. Is there a better way that does not require 1" to 1-1/8" thick drywall?
The answer is different between a structure supported by brick and a brick faced (brick veneer) wood structure.
It also depends if you want the door flush with the brick or inset from the brick.
The jamb extensions address the situation where the door assembly is smaller than the combined wall thicknesses
In general, doors are attached to the building structure. It sounds like your structure is the brick.
I personally like the inset look, so that would mean lining and waterproofing the brick rough opening with wood (typically 2x4s, treated). Then the door and exterior trims would attach to that.
On the interior, vapor barrier (semi permeable, like Tyvek, insulation and framing. The framing should be tied into the rough framing of the door.. Jamb extensions typically extend the door jamb out to thickness of where the drywall will be, making a natural place to cutoff the crywall.
After drywall installation, interior trims cover the small gaps between the jambs and the drywall.
Oh it will sag so bad! Use piece of MDO or birch plwood with a glued on or iron on edge, if you need to keep the thin edge. If the run is over 8 ft. glue the but joints with a biscuits or spline. 3/4" plywood will work best for this and you can profile the glued on edge in this case to a smaller profile if you want it thinner than 3/4"
If it is a matter of preferring it to be in the beam, but do not want to ruin its integrity, you can box it in with drywall, add a nailer on the ceiling and create a wider box to hold the light beside the beam, but contained in an enclosure. If the beam is structural and esthetic, you may be able to re-wrap the beam in the same wood and finish, just make it wider.
Best Answer
Better insulation between the studs helps a lot. You've probably got or your builder is spec'ing fiberglass, which isn't great for sound dampening. Upgrade to mineral wool. Also, a layer of rigid foam or preferably mineral wool on the outside of the wall--covering the plywood or OSB sheathing--will help a lot too.
Better windows also help, if you haven't bought them yet. Triple pane makes a difference vs double-pane.
If everything is already built, then obviously all of those options are fairly disruptive, and increasing the thickness of the drywall on the interior side is a decent approach.