Wall Construction Questions

[smellyfuzz]

Ok, after reading a little on the SAE site, if I understand correctly, in my basement, insulation right on the brick walls, then plaster board (sheet rock), then studs, more insulation, cloth, Slots.

Questions;

1) How does one fasten insulation to brick ?

2) How does one fasten sheet rock to insulation ?

3) What kind of insulation on the brick walls, must it be 703 ?

4) What are the consequences of skipping the first two steps, insulation then sheet rock and just studing out, insulating, cloth and slots ?

5) What if I just insulate, plaster board and minimal studding to separate rooms ?


Sean

[lomky]

Going from a purely construction basis (I'm still learnin' acoustics) you need to frame the walls i.e. put up 2x4's. The idea (I believe) is to not have the wall frames touching the concrete if you wanna do the room within a room. That way if you have 16" centers you can put the insulation in between the studs, don't worry they'll stay. After you can board (the construction way of saying, apply sheet rock) by screwing into the studs. Not sure if that answers your question, and apologies if I insulted your intelligence.

[lomky]

I'm stupid, I didn't answer you at all, sorry.

[knightfly]

From your question, I'm assuming you're referring to John's "inside out" wall construction - if so, then

1. You can use 703, which is semi-rigid and will stand by itself - this is better (by about 2-3 dB) for inside the wall than regular batt insulation, but if it's a basement that little bit of extra sound proofing may not be important. You could use foil-faced "fluffy stuff" and liquid nails, and glue the backing to the bricks - but only if the bricks stay DRY year round, otherwise you need to first WATERPROOF the walls, or you'll be really sorry. Insulation INSIDE the wall doesn't make any difference to ACOUSTICS, its main purpose is to break up sound waves within the wall and reduce the amount of transmission, either THROUGH the wall or BACK through the inner wall into the acoustic space.

2. You DON'T. If you're using soft batts, you frame the wall while it's laying down on the floor, run a continuous bead of acoustic caulk on each frame member, fasten the wallboard on top, staple the batts to the sheet rock, then tip up the wall and connect/caulk it to the next wall. If you're using rigid board insulation, such as 703 or Knauf board, you would attach it to the sheet rock with construction adhesive before tipping the wall into place.

3. No, it's just easier if you can find it. Commercial Insulation companies tend to be the only sources, unless you want to buy it at realtraps.com and pay shipping.

4. sounds like that would be skipping the second leaf (mass center) of the wall - OK if you're not concerned with sound getting in/out, otherwise a bad idea.

5. Depends on whether you need sound proofing between rooms. If you're talking about between control room and tracking room, you won't like the lack of isolation. One reason is you can't tell what a source will sound like "on tape", because it will be bleeding through the cheesy wall too much to tell what the speakers sound like.

Best bang for buck in soundproof walls (no matter WHAT your budget) is two mass centers (leaves) separated by ONE air space. A space is still considered air even if filled with insulation.

Check here for some relative ideas on wall effectiveness

http://www.homer.com.au/phpBB2/viewt...p?t=86&start=0

scroll down to the charts posted by John on Mar 01, and my comments on Mar 17...

Then go here (takes a while to download) BEFORE you run this test, pay attention to the warnings - you could blow your speakers or ears if not careful...

http://www.auralexuniversity.com/NeighborsReal.html

Keep in mind that Auralex SELLS foam and sheet blok - and that BOTH products are pretty expensive. Other than that, it's a good way to learn what the numbers really mean... Steve