Rockwool filling between joists, need acoustically transparent/inexpensive fabric ..

[rich121]

This is my 1st post here... I have looked around and really like this forum. I look forward to meeting everyone here.

I have gutted my home, removed a room, and changed the wall layout so that I have a larger/better room for audio/video enjoyment.

The room is 24'x18'x8'...the 8' being the low ceiling, which in compensating for this, I will fill the 2"x6" ceiling joists with 5 1/2" of rockwool (5 1/2" is the limit, as there is a 2nd floor), then cover this with a good quality, acoustically transparent cloth.

Does anyone know of a source for such an inexpensive fabric?


Thanks,

Rick

 

[PSWii60]

If your looking for something like speaker grill cloth check parts express.

 

[Rickster71]

Hi Rich, welcome to Audioholics

What will you use to support the insulation?
Over time, the rockwool will sag; I don't think the acoustically transparent cloth will be enough to support it.
You may want to check, I think for insurance purposes & building codes, it will have to be sheet rocked.

 

[rich121]

the space between the joists is only 16" on center.
No code requirement for the ceiling, only the walls.
At this point, I just need some ideas of inexpensive, Class A fire rated (which all comercialial use fabric has to have), acoustically non-reflective fabric.


Rick

 

[lsiberian]

I'd suggest trying burlap. Not sure how well it would work though.

 

[rich121]

I'd suggest trying burlap. Not sure how well it would work though.

Burlap might be a good choice. I'm sure it's not Class A fire rated, but I think there are products made that I could spray it and it would be more safe.

Rick

 

[rich121]

Anyone else have suggestions? Would be greatly appreciated!






Rick

 

[just-some-guy]

black felt here. $4 yard at wallly mart.

 

[Rickster71]

Here is some other info: http://www.soundproofing.org/infopages/channel.htm

 

[dougg]

Spray on Fire Treatment........

Fire Marshell let us use this on Fabric Wall Treatment, UL, FM, rated for Commerical use. You can pick any Fabric you wish with this!

http://www.safetythink.com/Workplace+Safety/Flame+Stop+I+Fire+Retardant?gclid=CJ_it6ern54CFcNx5QodZzdjmw

Doug S.

 

[mtrycrafts]

Burlap might be a good choice. I'm sure it's not Class A fire rated, but I think there are products made that I could spray it and it would be more safe.

Rick

If you are leaving the whole ceiling uncovered with just the insulation there, your room may be too dead.
A couple of makers of acoustic panels and knowledgeable folks post here and may want to send them an email before you do anything as they would not mind questions such as yours. Just saw one of the posters moniker: bpape.
Search for him.

 

[bpape]

There are a couple issues here.

First, if you don't drywall the ceiling and leave it open, you're reducing your isolation into and out of the space.

Second, as has been stated, that's a LOT of full range absorption when you consider you also still have to deal with the front wall and the side reflection points - definitely could be too dead overall.


If you must leave the ceiling open, I'd recommend just doing maybe 2' around the perimeter and a little over your head to deal with height issues.

Generally, using an insulated drywall ceiling and a bit of additional absorption on the ceiling AFTER the drywall is a much preferable solution.

Bryan

 

[rich121]

I appreciate the posts guys...I am checking out the materials now.

Any other suggestions would also be appreciated...

Again, Thanks!!!


Rick

 

[rich121]

There are a couple issues here.

First, if you don't drywall the ceiling and leave it open, you're reducing your isolation into and out of the space.

Second, as has been stated, that's a LOT of full range absorption when you consider you also still have to deal with the front wall and the side reflection points - definitely could be too dead overall.


If you must leave the ceiling open, I'd recommend just doing maybe 2' around the perimeter and a little over your head to deal with height issues.

Generally, using an insulated drywall ceiling and a bit of additional absorption on the ceiling AFTER the drywall is a much preferable solution.

Bryan

This is starting to get complicated... I wish I could afford to have a sound engineer figure this out, but I can't.
It will be a few weeks before I will start the actual work, so I have time to figure out something.

So, It would be better to put the rockwool in the celing, then cover with sheetrock (just one layer 1/2" or 2 layer?) Then build acoustical panels to put on the ceiling later?
I want to do what's best, and if this is better, and still will give the impression sonically, of a much taller ceiling, then I need to plan for that.

I really appreciate you guys letting me know it could be a mistake to leave the ceiling uncovered...I was just going by what I was told by others.


Again, any and all suggestions are welcome!




Rick

 

[bpape]

Just use standard fluffy insulation in the joist cavities and drywall over it. We're just trying to get a little extra isolation and stop it from ringing like a drum.

Adding panels later is definitely much less expensive and allows a better balance of treatments in the room.

Bryan

 

[rich121]

Just use standard fluffy insulation in the joist cavities and drywall over it. We're just trying to get a little extra isolation and stop it from ringing like a drum.

Adding panels later is definitely much less expensive and allows a better balance of treatments in the room.

Bryan

Bryan,

I really appreciate your help...this will save me quite a few dollars over the rockwool too...
I have a staircase in rear corner of the room, should I treat the inside before I cover it?

Also, I don't have a problem with sound leaving the room to other parts of the house. My daughters bedroom is above the room and is not really a problem.

I have central heat, and a wall mounted air conditioner, as you can see in the picture.

Would it be helpful if I showed more pictures of the room, ceiling or?


Again, I appreciate your help!


Rick

 

[mperfct]

I stuffed my stairs full of insulation, even though it's not in the theater, it gave the benefit of having the stairs seem much more solid.

 

[bpape]

Yes. Fill the stair undersides before walling it in.

While sound getting OUT may not be an issue, sound getting IN definitely does. It will raise your noise floor a limit the potential dynamic range of the equipment/room system.

Bryan

 

[mtrycrafts]

I stuffed my stairs full of insulation, even though it's not in the theater, it gave the benefit of having the stairs seem much more solid.

I did the same in my house. And, on some stairs, id reduces the stepping noises.

 

[rich121]

Just use standard fluffy insulation in the joist cavities and drywall over it. We're just trying to get a little extra isolation and stop it from ringing like a drum.

Adding panels later is definitely much less expensive and allows a better balance of treatments in the room.

Bryan

What drywall do you recommend for the ceiling?
1 layer of 1/2"
1 layer of 5/8"
or multiple layers?

And drywall for the walls, I have been told by a number of people to double layer 5/8" on the walls, but on opposing walls only do a single layer, is this also what you would recommend?