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alkizmo
join:2007-06-25
Pierrefonds, QC

alkizmo

Member

Misc questions on drywall & sound dampening

My basement is approaching the finishing steps. Tomorrow we're putting up the drywall for the ceiling (walls already up) and the mud&tape process should start.

I'll start with the short answer question:

If you had to choose ONE of the two following options for dampening sound from upstairs, which would it be? This or that?

They'll cost me about the same, but the wallet hurts now so I don't want to do both especially since sound dampening isn't exactly super important. I just want to diminish a bit the sound of people walking on the floor above (hardwood).

Resilient channels would be trickier to install properly, especially since my recessed lights would need to float above the drywall with the trim not connected to the light itself (glued to the drywall). With the pink stuff, I'd need to leave the space around the recessed lights uninsulated, meaning sound will still get through that. Either way, I'm not looking for anything complicated like they do on the AVS forum.

Long question
I will be doing the mud&tape myself. I got quotes around 600$ & 1000$ to get it done and that's out of my budget. I'd rather take my sweet time (I cashed in tons of vacation time) and not spend that money.

What are your personal preferences in tools/materials, if you were to do it for the first time, or at least, to keep it simple (but slow).

- Would you use tape or mesh for the butt and tapered joints (I know always tape for corners, anyway I will use paper faced metal beads).

- Would you use a mud pan or a hawk?

- Setting type 90 minutes for the first layer then use premixed for other layers, or all setting type?

I know there are TONS of guides and forum topics found on Google regarding this, but they never say the same things. However, I know you guys better than those random online guides and obscure forum threads. So any tips are appreciated. Keep in mind that I CAN spend a lot of time on this, so tips that assure quality results (even if slow) will be greatly appreciated.

LazMan
Premium Member
join:2003-03-26
Beverly Hills, CA

LazMan

Premium Member

I'd go for the 3rd option... Roxel is a better sound dampener then fibreglass, in my experience... It's what I'd use.

As for taping, I prefer a pan; and use mesh on tapered joints, paper on butts and corners...

Use a setting compound for the first coat, and go thin... It's not really sandable, so it's a bear to smooth out, if its on heavy. Premix for 2nd and 3rd costs, light sand between.

As an aside, typically you board the ceiling first, so that the edges ar supported by the wall board... Makes the corner less prone to cracking.

Lurch77
Premium Member
join:2001-11-22
Green Bay, WI

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A lot of people claim insulation does little. But we put it in the interior walls surrounding the bathrooms and our master bedroom when we built. It worked quite well given the cheap cost and simple install. I'm sure there are more ideal options, but not at this price point.

ArthurS
Watch Those Blinking Lights
Premium Member
join:2000-10-28
Hamilton, ON

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Actually I'd be in favour of doing BOTH the Roxul insulation AND resilient channel for the ceiling, with a few additional suggestions:

1. Make sure that the insulation does not touch the drywall, airspace is your friend, and provides a lot of acoustical benefit.
2. Stop the drywall about a 1/4" from the side walls. Why? Because if you physically connect the ceiling that is hung on resilient channel to your walls that are not isolated, you negate all the acoustical benefits in floating the ceiling from the house structure. Fill this gap with a bead of non-hardening acoustical caulk. Seal all penetrations through this ceiling (eg air ducts, electrical) with acoustical caulk as well.
3. Make sure you use the right length drywall screws so that you don't run the screw through the drywall, through the resilient channel, and to the structure of the house, and thus negating the benefit of resilient channel once again.

alkizmo
join:2007-06-25
Pierrefonds, QC

alkizmo

Member

said by LazMan:

I'd go for the 3rd option... Roxel is a better sound dampener then fibreglass, in my experience... It's what I'd use.

I've read some discussions where there would be a debate on whether Roxul is that much better than fiberglass for sound.

While I love Roxul as a heat insulation material, I'm not ready (anymore) to pay for the Safe'N'Sound for my ceiling just for a bit of an improvement over pink stuff.

For my 450 sqft ceiling the price difference between the two is HUGE.

74$ Fiberglass
270$ Safe'N'Sound (Roxul)
said by LazMan:

As for taping, I prefer a pan; and use mesh on tapered joints, paper on butts and corners...

Use a setting compound for the first coat, and go thin... It's not really sandable, so it's a bear to smooth out, if its on heavy. Premix for 2nd and 3rd costs, light sand between.

Thanks, I'll put your vote on that option.
said by LazMan:

As an aside, typically you board the ceiling first, so that the edges ar supported by the wall board... Makes the corner less prone to cracking.

Yeah I was aware of that, but as you can see, I still am not sure what to do with the ceiling and I needed to keep progressing. So I went with the walls first. That left the resilient channel option open, where if I go that path, the ceiling wouldn't be resting against the wall drywall anyway.
said by Lurch77:

A lot of people claim insulation does little. But we put it in the interior walls surrounding the bathrooms and our master bedroom when we built. It worked quite well given the cheap cost and simple install. I'm sure there are more ideal options, but not at this price point.

It's always about the price point
The AVS forums have VERY good guides and solutions, but they're all at very high price points for needs beyond mine. I don't want sound proofing. I still want to hear what's going on through the ceiling because my kids will be playing in there, however I don't need to hear them as clearly as if they were standing next to me
said by ArthurS:

Actually I'd be in favour of doing BOTH the Roxul insulation AND resilient channel for the ceiling

As shown above, Roxul is out of the price range. 270$ vs. 74$, they aren't the same in performance, but I'm sure the fiberglass has a better bang for the buck. Though when I wrote this thread, I only saw the 48$ 110 SQFT fiberglass pack in stores. I didn't know they sold a slightly thinner pack that has 170 sqft for 37$. I actually might be willing to go for both resilient channels and the pink stuff.
said by ArthurS:

1. Make sure that the insulation does not touch the drywall, airspace is your friend, and provides a lot of acoustical benefit.

Should I try to leave an air space above AND under the insulation? Or can I just push it up against the subfloor above?
said by ArthurS:

2. Stop the drywall about a 1/4" from the side walls. Why? Because if you physically connect the ceiling that is hung on resilient channel to your walls that are not isolated, you negate all the acoustical benefits in floating the ceiling from the house structure. Fill this gap with a bead of non-hardening acoustical caulk. Seal all penetrations through this ceiling (eg air ducts, electrical) with acoustical caulk as well.

Yup, gotta let it "float". Though I wonder how I can cover that gap. If I mud&tape it, it will harden and transfer vibrations. I could hang a crown molding and glue it to the ceiling but let is slide freely against the wall?
said by ArthurS:

3. Make sure you use the right length drywall screws so that you don't run the screw through the drywall, through the resilient channel, and to the structure of the house, and thus negating the benefit of resilient channel once again.

Yup if I buy resilient channels, I'll get some short metal stud screws. That stuff is cheap anyway.

ArthurS
Watch Those Blinking Lights
Premium Member
join:2000-10-28
Hamilton, ON

ArthurS

Premium Member

said by alkizmo:

said by ArthurS:

Actually I'd be in favour of doing BOTH the Roxul insulation AND resilient channel for the ceiling

As shown above, Roxul is out of the price range. 270$ vs. 74$, they aren't the same in performance, but I'm sure the fiberglass has a better bang for the buck. Though when I wrote this thread, I only saw the 48$ 110 SQFT fiberglass pack in stores. I didn't know they sold a slightly thinner pack that has 170 sqft for 37$. I actually might be willing to go for both resilient channels and the pink stuff.

Yeah, in this case, regular fiberglass should do fine here. Didn't realize the price difference was so great. Are you comparing the same size and density insulation?
said by alkizmo:

said by ArthurS:

1. Make sure that the insulation does not touch the drywall, airspace is your friend, and provides a lot of acoustical benefit.

Should I try to leave an air space above AND under the insulation? Or can I just push it up against the subfloor above?

I'd push it up against the subfloor above, and secure it somehow so it doesn't fall down on top of your floating ceiling. The airgap should always be on the side that is being physically isolated as a decoupling mechanism.
said by alkizmo:

said by ArthurS:

2. Stop the drywall about a 1/4" from the side walls. Why? Because if you physically connect the ceiling that is hung on resilient channel to your walls that are not isolated, you negate all the acoustical benefits in floating the ceiling from the house structure. Fill this gap with a bead of non-hardening acoustical caulk. Seal all penetrations through this ceiling (eg air ducts, electrical) with acoustical caulk as well.

Yup, gotta let it "float". Though I wonder how I can cover that gap. If I mud&tape it, it will harden and transfer vibrations. I could hang a crown molding and glue it to the ceiling but let is slide freely against the wall?

Definitely you don't want to mud and tape over the acoustical caulk. Honestly I don't think anyone will notice a 1/4" of caulk all around the edges if you smooth it properly. But if you must, attach some crown molding to the walls, stopping a fraction of an inch short of the ceiling. Or do something decorative with the crown molding by hiding LED light strings behind it and leaving an inch or two gap. Make your basement look high tech!
said by alkizmo:

said by ArthurS:

3. Make sure you use the right length drywall screws so that you don't run the screw through the drywall, through the resilient channel, and to the structure of the house, and thus negating the benefit of resilient channel once again.

Yup if I buy resilient channels, I'll get some short metal stud screws. That stuff is cheap anyway.

Yep, an often overlooked and neglected step. Short screws are cheaper than ones that are too long!

aurgathor
join:2002-12-01
Lynnwood, WA

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I don't think fiberglass is a particularly good material for stopping sound, but it's better than nothing. I think the more important thing is de-coupling the floor above from the ceiling.

alkizmo
join:2007-06-25
Pierrefonds, QC

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Member

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said by ArthurS:

Yeah, in this case, regular fiberglass should do fine here. Didn't realize the price difference was so great. Are you comparing the same size and density insulation?

i made a mistake, 110$ for pink stuff, 288$ roxul.
I still get more extra pink stuff than needed but it is 2.5" thick vs. roxull 3".
said by ArthurS:

Yep, an often overlooked and neglected step. Short screws are cheaper than ones that are too long!

well i already have the normal screws so its an extra purchase.

Anyway i will go with both pink + rc and see how the ceiling gap looks (deal with it later).

LazMan
Premium Member
join:2003-03-26
Beverly Hills, CA

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You've got to remember, density is a big part of dampening sound; regular fibreglass, especially at a lower 'R' rating; isn't very dense. It'll help, sure - but Roxul will do a better job.

Personally, I'd find the extra $200 bucks... If you're putting the money out to do it; a couple bucks more to do it better, is probably well spent. Doubly so since its a drywall ceiling; and you can't go back and change it.

But that's my opinion...

alkizmo
join:2007-06-25
Pierrefonds, QC

alkizmo

Member

said by LazMan:

Personally, I'd find the extra $200 bucks... If you're putting the money out to do it; a couple bucks more to do it better, is probably well spent. Doubly so since its a drywall ceiling; and you can't go back and change it

It's a lot about the fact that I'm not sold on Roxul's greatly added value.

»www.bobgolds.com/Absorpt ··· ents.htm

I compared the Safe'N'Sound 3" to the Unfaced (in air location) 2.5" fluffy pink Owen's Corning and the differences are negligible.

The extra 200$ is just one thing, but the same thinking applied to everything goes in the thousands. Why not double layer drywall, green glue, pile on the $$$$. I just want some muffling of the noise between the two floors.

I spent a TON on the thermal insulation so I'm broke

pende_tim
Premium Member
join:2004-01-04
Selbyville, DE

pende_tim

Premium Member

To paraphrase a wise old sage .. The quality of a job is long remembered after the cost is forgotten... Do I right the first time.

If money is a problem, is there anything exposed you could defer till later. As others have said, the ceiling, once closed in will not be something you will revisit

robbin
Mod
join:2000-09-21
Leander, TX

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said by alkizmo:

I spent a TON on the thermal insulation so I'm broke

Perhaps you shouldn't vacation in such far away places when trying to remodel your home.

Insulation is a bad place to cut costs but if you need to save funds why not skip sheetrocking the ceiling and just paint everything up there black. Then come back later after your funds have recovered and do the ceiling.

alkizmo
join:2007-06-25
Pierrefonds, QC

alkizmo

Member

said by pende_tim:

If money is a problem, is there anything exposed you could defer till later. As others have said, the ceiling, once closed in will not be something you will revisit

The issue here at this point is that I disagree that Roxul is worth the extra 200$ since no ratings/numbers show a noticeable difference between Safe'N'Sound vs. pink stuff.
said by robbin:

Perhaps you shouldn't vacation in such far away places when trying to remodel your home.

Vacation? I wouldn't call that vacation, well maybe my wife would, but I didn't "vacation"
said by pende_tim:

Insulation is a bad place to cut costs but if you need to save funds why not skip sheetrocking the ceiling and just paint everything up there black. Then come back later after your funds have recovered and do the ceiling.

I didn't cut costs with insulation (thermal). It's already up and sealed.

Again, are we arguing about roxul vs. fiberglass?
I did say (later on) that I was going to do both fiberglass + resilient channels right?
Parneli
join:2004-12-28
Naperville, IL

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said by alkizmo:

said by LazMan:

Personally, I'd find the extra $200 bucks... If you're putting the money out to do it; a couple bucks more to do it better, is probably well spent. Doubly so since its a drywall ceiling; and you can't go back and change it

It's a lot about the fact that I'm not sold on Roxul's greatly added value.

»www.bobgolds.com/Absorpt ··· ents.htm

I dunno. I bought some a few years back when nobody stocked it and it was special order.

I see the chart and agree that it doesn't show a huge difference... but that certainly wasn't my experience. I'm not sure where the discrepancy is.

alkizmo
join:2007-06-25
Pierrefonds, QC

alkizmo

Member

So I put up the cheap fiberglass and I can already say it does exactly what I wanted as result (even before the drywall is hooked to the resilient channels).

My uncle and I were working downstairs all day then my wife brought back our son from school. As he trashed the upstairs with his toys, I could definitively tell that the noise was dampened quite a lot (muffled) to the level I desired. It will be even better when the drywall is hooked up.

So I'm glad I saved 200$ since I'm getting better* results than desired.

*Pending drywall

Jan Janowski
Premium Member
join:2000-06-18
Waynesville, NC
·Carolina Mountai..
Synology RT2600ac
Linksys E2000

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My builder is looking into Acousti-block for sound deading.
It's a rubber liner that goes behind the drywall.

»info.acoustiblok.com/aco ··· =true%22

Bruschi
Premium Member
join:2001-04-16
Cape Cod

Bruschi

Premium Member

said by Jan Janowski:

My builder is looking into Acousti-block for sound deading.
It's a rubber liner that goes behind the drywall.

»info.acoustiblok.com/aco ··· =true%22

»www.acoustiblok.com/ and »www.quietrock.com/ together. One sheet of quietrock= 8 sheets of reg drywall.

aurgathor
join:2002-12-01
Lynnwood, WA

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Some very "interesting" stuff on that web site.

"The viscoelastic principle is isothermal adiabatic. "

"Thus one 3mm (1/8") layer of Acoustiblok in a standard stud wall will result in more sound reduction than 12-inches of poured concrete! "

VioletVenom
Lets go Gators
Premium Member
join:2002-01-02
Gainesville, FL

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Forget about using resilient channel if you have cans in the ceiling. A hole in the wall/ceiling is the biggest infiltration of sound. Anything you gained by decoupling the drywall from the floor joists would be lost by sound transmission through the cans. A heavier (denser) insulation would be the best bang for your buck. Stopping sound transmission through floor/ceilings is really tricky.