How does this design look? How do we install the ceiling?

Attached is a .pdf 3d model and plan of my room. Are there any obvious fatal flaws in it? The 3d model shows the entrance/door. As you will see, the original opening is so close to the original wall, that the door of the new room is offset by about 10". This makes the opening only about 20" wide - which kinda sucks. As I am calulating the different weights I decided to check the weight of the ceiling alone with the two upper layers of drywall. That means theoretically we assemble the ceiling on the ground then add the two upper drywall layers and then lift it in to place. The total weight is 930 lbs. No way. So we build the ceiling in two parts and lift each one separately. Still a bit heavy I think for the two of us ( 465 lbs ). So we just do the framing and lift it into place. But then how do we screw the outer drywall? We only have a 6" clearance on top and on the sides from the original room walls. See attached .pdf 3d model

looks like you have some reading to do before you move things forward. the green lined structure you have in the .jpg is your outer wall right? What is that buildt of? Search for info on why the three leaf wall you have is a no-no. regarding the opening you'll probably build the inner structure angled so that the inner dorr is tilted towards the existing dorr.. say 45° or so. a :arrow:

From what I understand, the 3-leaf system only exists withing a standalone structure. So isn't the outer wall negligible because it's not in my "isolated" room? Is this incorrect? I asked about this before and read through many of the 3-leaf examples here. Man... I've done soo much reading. And every time I post here to clear some misunderstandings up, people just tell me to read more! :?

errr... well reading a lot will enlighten you on the many things regarding isolation and building the room properly. I know this will take a lot of time and energy and this will not progress at all building-wise but in the end things will go a lot faster and the result will be a lot better. re: (your walls): the outer wall depicted is not facing the world outside or another room? if yes, that would be your outer leaf. Your inner leaf (2nd) would be the one facing the inside of your room. But it seems you're trying to build the room with gysum boards on the inside of your studs. In my undertsanding of the 3 leaf concept that would be the third leaf. I know a lot of this doesn't make sence when thinking of how to prevent sound from entering the structure. But to get the best result you add more mass to the inner leaf and the outer leaf and get rid of the third (inside) leaf hence the term Mass-Air-Mass, where the two masses are your outer and inner leaf and the air the insulation and air between joists. So, maybe you should reconsider the staggered studs since the don't make any sence when not attached to anything. otherwise just wait until somebody with more credability chimes in on this subject (Rod, Steve anyone??) a :arrow:

Well.. I don't understand then. Adjacent to me is another room, then air, then another wall at the other end of that room. Then there's a hallway and another wall after that. When exactly do you stop counting leafs? :?

Hi speedo I know it can become frustating. But don't loose hope. What Andreas is saying is simply stop before you put time and effort and do anything that just won't work as expected. Heck i've built a floating control room floor that isn't working because i didn't read enough to understand the idea behind it. :evil: The priciple is simple i see it like this it's Mass -Air- Mass (i am sure you've read about it) where Mass (in our case gypsum board) then Air, then Mass again (gypsum board again). Makes the best isolation techinque between two rooms as we speak. So, mass an air space and mass again whenever you build something that has more than one air space between the two masses you create a triple, quad ect... leaf structure (bad) that separate two rooms. Now i understand you're confused that if you take into account the wall at the other end of the room it become an Xnumber of leaf construction BUT just don't think about it this way, think double walls between two rooms period. hope this is clear regards

What I still don't understand is that there is airspace between the 2 rooms already. There's already a regular wall there. So does this count as Mass-Air-Mass already??

You should post a detailed plan of what you have right now and what you want to do. Mass air mass include decoupling ( not touching ) structure, a regular wall do not have any decoupling between it's two flimsy masses, so no it doesn't count as Mass air Mass. If you already have a wall that separate two rooms with Gypsum board on both sides then all you have to do is to remove the GB on the studio side of the wall and then fill it with insulation then build you studio wall in front separated by at least 1", same is true for ceiling. Are you begining to get the idea ! :wink: regards

orangenumerik wrote:

a regular wall do not have any decoupling between it's two flimsy masses, so no it doesn't count as Mass air Mass. regards

Hey Eric, just had an idea or two. That's pretty close but it does count as mass air mass. Decoupling is a different issue and is derived in many manners as these guys have shown us, but a regular wall in a house...it is mass air mass. Sheetrock, air or insulation ( if any) in the framed air space and sheetrock again. I recognize this principle in many instruments as well. Drums, acoustic guitars even my upright piano;) Density air density, whatever it takes to produce it, it is mass air mass. Hope that helps

Xspace Technically, you're right a regular wall is MAM i won't argue with that. My point was that in a studio or "soundproofing" situation MAM used with decoupling will yield the best results. I didn't want to confused our friend here. You'll agree that a regular wall (Sheetrock air or insulation in the frame and sheetrock again) won't give brilliant results as far as sound isolation goes. regards