Wall construction & code considerations

EddieCD · Post by **EddieCD** » Thu Sep 30, 2004 3:17 am

Hi. I'm still very slowly building my studio in my basement and I've gotten to a point where I'm going to start putting the walls up. I've been reading the sticky posts here about construction techniques (thanks, by the way, for those!) and I have a question about wall construction.

I want to build two rooms in my basement; one room right next to the other. I understand the concept of the 2 leaf wall system approach, and I believe the rule of thumb is that the two frames of the walls (one for one room, one for the other) should not be rigidly coupled. Can I assume this means that they are also not coupled to the floor joists of the room above my basement?

If this is the case, how do you build the walls of one room or the other? Do you frame up all 4 walls such that they attach to each other but not the joists above? Is that rigid enough? Is that to code in most areas?

In addition, I've read about the "staggered studs" approach and again I wonder how much this really helps when the header 2x6 still couples the walls together?

Thanks in advance for any thoughts you may have.
Ed

AVare · Post by **AVare** » Thu Sep 30, 2004 8:33 am

I want to build two rooms in my basement; one room right next to the other. I understand the concept of the 2 leaf wall system approach, and I believe the rule of thumb is that the two frames of the walls (one for one room, one for the other) should not be rigidly coupled. Can I assume this means that they are also not coupled to the floor joists of the room above my basement?

Easy one. The ceilings, al;so separate from the floor above.

In addition, I've read about the "staggered studs" approach and again I wonder how much this really helps when the header 2x6 still couples the walls together?

More frustrating for you, maybe. NRC IR-761 ( idon't have the link handy, doa search here for it) has the results of 350 wall constructions including several staggered stud walls.

You can see the effect of changing stud size,type, gypsum board type/thickness, and more.

Enjoy!
Andre

cadesignr · Post by **cadesignr** » Thu Sep 30, 2004 4:57 pm

I want to build two rooms in my basement; one room right next to the other. I understand the concept of the 2 leaf wall system approach, and I believe the rule of thumb is that the two frames of the walls (one for one room, one for the other) should not be rigidly coupled. Can I assume this means that they are also not coupled to the floor joists of the room above my basement?

Please correct me if "I"am wrong here, but I believe you are looking at this differently than Andre. It sounds as if your intention is to divide ONE large room into TWO, by simply building a double wall with NO connection between the two

(one for one room, one for the other)

That is ok, except one thing. How do you hold them vertically unless you fasten them to the existing joists above and floor below and or to each other. THAT is the structural isolation problem.
I believe Andre is talking about COMPLETE ROOMS WITHIN A ROOM(otherwise how would you build a seperate ceiling). That means...floor, 4 walls, ceiling.......for each of the two rooms

That creates a self supporting structure for each room. IF you are ONLY building these two walls there is a way to isolate the connection at the existing floor joists above via sway isolation brackets, . However, IF the new double walls are perpendicular to the joists, which I assume they are, then flanking over these walls via the void space between joists must be delt with too, which is no easy task, considering you must isolate this connection at the walls also, otherwise, structural transmission may occur.
I believe Steve has posteda detail of this type of connection but I don't know how to find it. Again, my assumption may be a brain fart , but it's only my .02 anyway.
fitZ

AVare · Post by **AVare** » Thu Sep 30, 2004 5:16 pm

I believe Andre is talking about COMPLETE ROOMS WITHIN A ROOM

You are 100% correct. Thanks for the clarification and your post.

Andre

EddieCD · Post by **EddieCD** » Thu Sep 30, 2004 10:23 pm

OK, I understand the replies so far, but allow me to ask you to bring this down to a 3rd grade reading level for me, please; and I'll explain my design a little better. Sorry, I'm still a little "green"

Yes, I am planning on building a "room within a room" except I didn't plan to lay a ceiling frame of 2x4s on top of the new walls I'm building for the new inside room. Instead, I was considering using RC on the existing joists of the floor above and then I was going to use acoustic caulk between the ceiling drywall and the new 4 walls.

But the question I'm trying to answer for myself is whether or not to build the 4 walls by attaching the header board of each wall to the floor joists of the floor above OR should I build the walls simply as 4 walls attached to each other at the corners and floor sill boards and NOT attached to the floor joists of the floor above. To me, the idea of not attaching the header boards to the floor above seems unsafe. Thoughts?

The key factor here is that 2 of the walls will be firmly attached to the concrete poured walls in my basement. This should give the structure the appropriate integrity, right? or not?

And that leads me to ask: I understand that most of the conversations are concerned with sound transmission between adjacent rooms on the same floor ... but in my case, my bigger issue is keeping the sound of my daughter & wife trampling around on the floor above my "sound room" from disrupting me...and that's where my question about decoupling the walls header boards from the floor joists above comes from.

Forgive me for not getting it the first time but I'm just a musician looking to build a descent sound room but the idea of actually having a live drummer playing a real drumset has me thinking of ways to do things better. Thanks for the posts so far ... I'm learning a lot.

Ed

AVare · Post by **AVare** » Fri Oct 01, 2004 7:40 am

It is a liitle difricault to answere questions with "should I" exactly. For best isolation, you want a ceiling separate from the floor above. Acousitcally, a ceiling or floor is just a wall on another surface.

so for best results, build a separate ceiling not connected to teh floor joists. Next step down is using hangers like Kinetics ICW hangers. Next step Pac-International RSIC type clips.

The use of RC is questionable in my mind. It has reduced low frequency isolation, which I think (note the qualifier!) is the most important part of musical isolation systems. Other people have different opinions.

Good luck!
Andre

cadesignr · Post by **cadesignr** » Fri Oct 01, 2004 8:03 am

Here is a typical illustration with the wall isolated with hanger isolators and RC.
fitZ

cadesignr · Post by **cadesignr** » Fri Oct 01, 2004 8:05 am

Here is one with the ceiling on hanger isolators/Unistrut/hatchannel
Just a drawing exercise, but illustrates it I believe.
fitZ