value of insulating interior walls

[saichele]

Looking for an opinion (bet this is the place)...

Have a bedroom I'm redoing for my (toddler) daughter. Outside walls had no insulation - they get R19, for about $100. Downstairs is blown cellulose. Attic is ~R50 cellulose. So that does it for the exterior envelope.

Is it worth $100 to do the interior walls, either for heat/drafts/comfort, or on the off chance she takes up the drums 12 yrs from now?

Thanks
Steve

 

[EatenByLimestone]

Do you have the walls open already? If they aren't open, I wouldn't think it's worth the trouble. If the walls are open, insulating the interior walls will never be cheaper. And even if she doesn't like the drums, do you think the music she will listen to will be better than the stuff you hear from the car next to you at the light?

Matt

 

[saichele]

I wouldn't even be considering it if the walls weren't open. I've got a while to think on it - I've probably got a week of evenings pulling nails and firring out the old studs to be flush.

So far so good though - she seems to like Beatles, Frampton, Pink Floyd. With a little luck, the worst I'll get is an Iron Butterfly drum solo.

Steve

 

[wtyamamoto]

Fiberglass insulation has the most effect from about 500hz and above. There is not too much attenutation below that. At lower frequencies, the drywall acts as a resonant filter. By backing the wall with fiberglass, you receive some attenuation as the air movement created by the drywall flexing in response to low frequencies is converted to heat via the the fibers of the fiberglass in concert with the airspace. To have any appreciable effect, the airspace needs to be about 4 inches thick. The best sound insulation will occur if there is a gap of about 1/2 to 1 inch between the back of the drywall and the insulation. If possible, a membrane such as plastic sheeting should be placed in front of the insulation right after the airspace. The membrane will act as a secondary abosorber by flexing with the air movement and will also serve to help reduce frequency reflections from the rear drywall from returning.

If you can, the ideal situation is to have an airgap between the drywall and the studs also - or maybe every other stud. This would lower the resonant frequency of the drywall and also reduce vibrational transmission from the studs to the drywall.

Sound-wise, there's a lot you could do if you're doing the construction yourself. I would recommend "The Master Handbook of Acoustics" by F. Alton Everest.

Wayne

 

[elkimmeg]

Forget about it not worth doing sound board is better anyways

 

[wg_bent]

Wayne is dead on here. Look up sound proofing on the web, and you'll find that fiberglass is poor at sound insulation.

There are other options, but not very cost effective, and not very practical for a bedroom. I'd give her an an iPod instead.

 

[BrotherBart]

Ah the memories. I insulated the interior walls of the center bedroom in my first house a bunch of years ago. Did it for sound deadening. The unexpected thing was that with the door closed and a window in the room it turned into a deep freeze in the winter. Even with the heat vent open. When we sold the house I warned the new owner not to close that door in the winter with a child sleeping in there. He would end up with a kidsickle.

 

[begreen]

Coming soon to a theatre near you - "Honey, I froze the kid!"

 

[webbie]

Looking for an opinion (bet this is the place)...

Have a bedroom I'm redoing for my (toddler) daughter. Outside walls had no insulation - they get R19, for about $100. Downstairs is blown cellulose. Attic is ~R50 cellulose. So that does it for the exterior envelope.

Is it worth $100 to do the interior walls, either for heat/drafts/comfort, or on the off chance she takes up the drums 12 yrs from now?

Thanks
Steve

I've built recording studios and also did a jam room in my basement almost total soundproof.

But, I don't know if you want to do this with your daughter. After all, you won't be able to hear the boyfriend and her in there, etc. etc. - Perhaps you want to install a microphone instead! No, come to think of it, you don't want to know what is really going on.

Anyway, for simple wall soundproofing, using one layer of cheap soundboard and then 5/8 firecode rock (mass) would be a good and inexpensive upgrade. Drums and bass will travel through most anything, as they shake the entire house unless in a massive basement like mine.

BTW, my basement room uses - on the ceiling:
1. Joist with FG insulation
2. One layer of soundboard nailed to bottom
3. One layer of mass-loaded vinyl (this is heavy vinyl with sand cast into it for mass)
4. Metal channels suspended on rubber clips so they float
5. 5/8 rock on the bottom of that
6. Flexible caulk or foam where it meets wall or beams and molding which is only nailed to wall (so ceiling can float).

I didn't go crazy on the wall because I read that ceiling was more important and sound that gets through walls still has to travel up though floor, so it is buffered. Just built stick walls 6" inside of the concrete and used one layer of soundboard and 5/8 rock.

Hope this helps.

We can have a full blast jam with bass, drums, keys, two guitars, PA, etc. and you can only slightly hear a tiny bit right above it and nothing at all on the 2nd floor.

 

[saichele]

Ah the memories. I insulated the interior walls of the center bedroom in my first house a bunch of years ago. Did it for sound deadening. The unexpected thing was that with the door closed and a window in the room it turned into a deep freeze in the winter. Even with the heat vent open. When we sold the house I warned the new owner not to close that door in the winter with a child sleeping in there. He would end up with a kidsickle.

The room was always really cold - it's at the far end of the house from the wood stovehad no wall insulation, and our ductwork is poor even inthe rare instances the furnace is running. At some point I'll be redoing the room below it, likely including installing some other form of space heat - pellet/corn or gas fireplace most likely. In the interim, it'll have a themostat controlled electric radiator (on a new dedicated circuit, I just don't trust the old BX that much).

Eventually she can use that circuit for the stereo.

Steve

 

[saichele]

Looking for an opinion (bet this is the place)...

Have a bedroom I'm redoing for my (toddler) daughter. Outside walls had no insulation - they get R19, for about $100. Downstairs is blown cellulose. Attic is ~R50 cellulose. So that does it for the exterior envelope.

Is it worth $100 to do the interior walls, either for heat/drafts/comfort, or on the off chance she takes up the drums 12 yrs from now?

Thanks
Steve

I've built recording studios and also did a jam room in my basement almost total soundproof.

But, I don't know if you want to do this with your daughter. After all, you won't be able to hear the boyfriend and her in there, etc. etc. - Perhaps you want to install a microphone instead! No, come to think of it, you don't want to know what is really going on.

Anyway, for simple wall soundproofing, using one layer of cheap soundboard and then 5/8 firecode rock (mass) would be a good and inexpensive upgrade. Drums and bass will travel through most anything, as they shake the entire house unless in a massive basement like mine.

BTW, my basement room uses - on the ceiling:
1. Joist with FG insulation
2. One layer of soundboard nailed to bottom
3. One layer of mass-loaded vinyl (this is heavy vinyl with sand cast into it for mass)
4. Metal channels suspended on rubber clips so they float
5. 5/8 rock on the bottom of that
6. Flexible caulk or foam where it meets wall or beams and molding which is only nailed to wall (so ceiling can float).

I didn't go crazy on the wall because I read that ceiling was more important and sound that gets through walls still has to travel up though floor, so it is buffered. Just built stick walls 6" inside of the concrete and used one layer of soundboard and 5/8 rock.

Hope this helps.

We can have a full blast jam with bass, drums, keys, two guitars, PA, etc. and you can only slightly hear a tiny bit right above it and nothing at all on the 2nd floor.

That's helpful, but overkill. I was debating $100 in materials, this sounds like somewhat more. And I still won;t hae aything in the floor, so maybe it doesn't matter.

If she takes up the drums she can practice in the barn. After I install the surveillance system.

Thanks though.
Steve

 

[elkimmeg]

Steve have you had any problems with the bx wiring? Do you have the kind with the two wire with the grounds? Bx does have some advantages. Harder for mice to eat threw the casing. Its the same wire gage as modern Romex If it is straight 2 wire no ground that's another issue?
Dont worry if she is like my childern, all of whom took Piano lessons. They grow tired of that pretty quickly, when you end up asking when they will practice. Eventually it is no longer worth if, as it is not in them they never practice.

Spend you money on wiring upgrades and improving the insulation envelope

BTW is there a return in the cold bedroom?

That huge Mac Mansion I having the problems with the mason, they are insulatiog every interior wall and ceiling.

So I ask the Mechanical contractor, what he has done to make provisions for the fact heat will not readilly rise from the first floor ceilings? He is clueless. We ask the designer of the mechanical system, he is clueless and did not know the entire interior was being insulated. I don't know how it effects the design, that's why I asked. I seen interior walls insulated around bathrooms for noise purpose actually quite common.. You touched on another point with the servalance camera. Maybe insulation and sound deading is not such a good idea? It may be an advantage to hear sounds and movement in that bedroom.

 

[saichele]

Haven't had any trouble with the BX, but some of the workmanship is a little iffy. Opened up one of the walls and they had the junction box hanging there, supported by the BX, no cover plate, extra knockouts missing. And it's the 2-wire variety that grounds through the sheathing. Seems OK in general, but things are just a little iffy. For instance, several ground switches on ceiling lights. And One switch appears to be crossed with another circuit - even when I cut the breaker, there was still enough juice in the sheathing to light the little test lamp. Not 110, but some.

It's a 100 yr old house it's been that way a long time, and will probably stay that way. But before we start putting in space heaters and hair dryers, I'd like to have some better handle on the wiring...

Steve