Stucco as mass?

Stick · Post by **Stick** » Sun Jul 17, 2005 2:34 am

Ok, so here's the latest question...

Two walls of the garage I will be building my studio in are stucco, facing the garage interior. We'll be tearing the walls out that aren't shared with the house and rebuilding, so those aren't an issue.

My guess is that if possible, I should rip the stucco out and then use the existing house interior wall as one of the masses, beefed up with a couple layers of whatever, then insulation, then my second wall. BTW, the brilliant builders that put up this house in the '60s didn't put insulation in the walls, so there is no insulation between the studs in the walls that the stucco is on.

It would be easier and cheaper if I could just leave the stucco and add layers to it on the garage side. How much differece in TL are we talking between the two options? If we're talking about 2 or 3 db, I'll probably save the expense.

Any other good options I'm not thinking of?

Stick · Post by **Stick** » Sun Jul 17, 2005 2:54 am

Here's the direction I'm heading at the moment, FWIW....

Post by **sharward** » Sun Jul 17, 2005 6:33 am

I'd recommend that the door to the main room swing inward. Also, bathroom doors usually swing inward.

Stick · Post by **Stick** » Sun Jul 17, 2005 6:38 am

Yeah, it's a rough mock up.

The bathroom will probably be a pocket door... it's a pretty tiny space.

You might be right on the control room... maybe in to the right is the way to go (from the entryway).

Regardless, I'm sooo not that far yet... I'm talking with a CAD guy this week and just need to know what to tell him to draw as far as the walls.

knightfly · Post by **knightfly** » Sun Jul 17, 2005 8:11 am

Biggest problem for iso between houses/studios is normally LOW frequencies; this is also the biggest diff in isolation between 2 and 3-leaf partitions. I'd pull the stucco out unless your family likes "boom-boom" with their TV or reading or sleeping...

Stucco has just a bit higher density than gypsum (50 PCF vs. 42), so from that standpoint it's OK. It's just that you'll lose somewhere around 8-10 dB or more at the low end by leaving that in place and making a 3-leaf wall.

Do a search on gypsum inserts (Keith probably has a link to the better ones, Keith??!?) This is the way I'd go. couple layers of gypsum between studs and against your house side's paneling, then your inner wall layers on separate frames... Steve

Stick · Post by **Stick** » Sun Jul 17, 2005 8:36 am

Alright... that's what I was looking for. Thanks Steve.

Post by **sharward** » Sun Jul 17, 2005 8:48 am

Stick wrote:You might be right on the control room... maybe in to the right is the way to go (from the entryway).

Exactly what I was thinking.

knightfly wrote:Do a search on gypsum inserts (Keith probably has a link to the better ones, Keith??!?)

Hark -- do I hear an order for a link?

chinocurva · Post by **chinocurva** » Sun Jul 17, 2005 8:53 am

Excuse me, Sticky, this has nothing to do with the thread...

But I have to ask...
Could you tell me which drawing soft is this you´re using? I think its fabulous...

Thanks, sorry, and good luck on your work!!

Chino.

Post by **sharward** » Sun Jul 17, 2005 8:56 am

Looks like Sketchup to me..

chinocurva · Post by **chinocurva** » Sun Jul 17, 2005 10:01 am

Thank you, Sharward!!

So, it´s the 'ketchup' then... hahahaha...!!

Seriously, I think is really great...

Thanks again!

Chino.

Stick · Post by **Stick** » Sun Jul 17, 2005 11:09 am

Sketchup it is.

Cool program... not too hard, even for us musicians.

-The Stickage

Stick · Post by **Stick** » Sat Jul 23, 2005 12:19 pm

knightfly wrote:This is the way I'd go. couple layers of gypsum between studs and against your house side's paneling, then your inner wall layers on separate frames... Steve

Ok, so the stucco's going to go. That'll be me with the sledgehammer.

All the rest of the outside walls we'll be rebuilding from scratch (the original builder did a few no nos. So, I was thinking of something like, from the outside, siding--styro--OSB (MDF?)--drywall--drywall--studs. Is that doable? It seems odd to be putting drywall on that side of the studs...

Now on the inside of the house, on the wall where the fireplace is, I'm going to do our layers of drywall. I was sort of leaning toward stud--3/4" MDF--5/8" drywall--1/2" drywall. Is this overkill in a set up where I won't be floating the floor? (The studio and the living room where the fireplace is share the same slab.) On the other shared wall, I'm planning to do the same layers, but the MDF and first drywall layer will have to go between the studs on the garage side.

It seems like the MDF first would be cool because then the drywall (and whatever else we hang on that wall) can just screw right into it.

Once we get to the studio walls, I'm not planning to use RC, because I think I'd rather have the low end stop rather than a little better high end stop. I don't think hi end is going to be the issue for me.

So, whachya'll think? Is three layers overkill? Maybe just 5/8" and 1/2" drywall? I'm foggy on the door/window TL comparisons to a wall like this. If I'm just doing solid wood doors, sealed of course, will they keep up with the 3 layers?

Again, I'm not going for commercial recording studio isolation... I'm after good enough and cheap.

Thanks for the guidance.

Stick · Post by **Stick** » Fri Aug 19, 2005 2:09 pm

A little bump to get some opinions on the layers...

Thanks,
b

knightfly · Post by **knightfly** » Wed Aug 24, 2005 6:47 pm

B, normal drywall doesn't have the racking resistance to be used on outside frames; there is a type of exterior rated drywall I've heard about but not used. If you're using some type of wood siding that won't leave air voids when used over another layer, I'd go with either durock in larger sheets or 3/4 OSB or wafer wood under the siding to get more mass in the outer leaf.

I'm not clear whether these will be double framed walls; any chance of a sketch/diagram of some sort?

also, unless you MUST because of code I'd NOT use foam - nearly zero mass, and puts vapor barrier in the wrong place for any but hot humid climate (with AC on nearly year 'round) - instead, if possible I'd do a Tyvek wrap on the outside, use either standard fiberglass or Fibrex/other SAFB's at 2.5 PCF density, leave a little gap between frames and do 2-3 layers of 5/8 gypsum on the inside (more insulation against the inner leaf for damping) - and of course caulk everything - somewhere around here there's a link to OSI 175 caulk for $3 a tube, can't beat that anywhere.

For the rest of your questions, I'm gonna need a sketch of your intentions so I can see what you're asking about - need to see all frame locations and any/all paneling layers from outside to inside.

Doors/windows - doubful if they will keep up with 3 layers, but this also depends on your positioning/framing. Sketch??

Post by **sharward** » Wed Aug 24, 2005 11:39 pm

knightfly wrote:. . . If you're using some type of wood siding that won't leave air voids when used over another layer, I'd go with either durock in larger sheets or 3/4 OSB or wafer wood under the siding to get more mass in the outer leaf.

Here are data sheets for Durock (by USG Corporation), and a similar/competing product called WonderBoard (by Custom Building Products).