Theater Room Design Questions

[Terry Dalton]

We are finishing our basement and part of it will be a theater room. I am
using acoustical tile for the drop ceiling and insulating underneath that.
I've read several places to that using two layers of R13 works well. The
GC doing my basement suggested one layer of R30. Does anyone have any
thoughts or experience with the differences of two layers vs one thicker
layer?

Thanks,
TD

[Ethan Winer]

Terry,

> Does anyone have any thoughts or experience with the differences of two
layers vs one thicker layer? <

If you're asking about laying fiberglass batts *above* the drop ceiling
tiles, it doesn't really matter how you arrive at the total thickness.
Though you don't need or want to use the kind with a paper facing. Just get
plain fiberglass. I'll also mention that 12 inches is better than using less
because it gives that much more bass trapping.

--Ethan

[Pete C.]

Ethan Winer wrote:
>
> Terry,
>
> > Does anyone have any thoughts or experience with the differences of two
> layers vs one thicker layer? <
>
> If you're asking about laying fiberglass batts *above* the drop ceiling
> tiles, it doesn't really matter how you arrive at the total thickness.
> Though you don't need or want to use the kind with a paper facing. Just get
> plain fiberglass. I'll also mention that 12 inches is better than using less
> because it gives that much more bass trapping.
>
> --Ethan

I'd suggest that while you do not want the kraft paper faced insulation
bats, this would be a good application for the plastic "encapsulated"
bats. They would be easier to handle and would reduce the tendency to
have fiberglass "rain" when you moved a ceiling tile to pull a cable or
whatever.

Pete C.

[Terry Dalton]

"Pete C." <aux3@snet.net> wrote in news:41FFE792.52F3A8CD@snet.net:

>
>
> Ethan Winer wrote:
>>
>> Terry,
>>
>> > Does anyone have any thoughts or experience with the differences of
>> > two
>> layers vs one thicker layer? <
>>
>> If you're asking about laying fiberglass batts *above* the drop
>> ceiling tiles, it doesn't really matter how you arrive at the total
>> thickness. Though you don't need or want to use the kind with a paper
>> facing. Just get plain fiberglass. I'll also mention that 12 inches
>> is better than using less because it gives that much more bass
>> trapping.
>>
>> --Ethan
>
> I'd suggest that while you do not want the kraft paper faced
> insulation bats, this would be a good application for the plastic
> "encapsulated" bats. They would be easier to handle and would reduce
> the tendency to have fiberglass "rain" when you moved a ceiling tile
> to pull a cable or whatever.
>
> Pete C.
>

When you say bats are you referring to the insulation strips or some other
form factor of insulation such as squares that adhere to the drop ceiling
tiles?

Thanks,
TD

[Pete C.]

The "strips" are normally called batts. It seems my spell checker killed
a "T" unfortunately.

Something similar to this:
http://www.owenscorning.com/around/insulation/products/miraflex.asp

They also have this:
http://www.owenscorning.com/around/sound/products/quietzone.asp but it's
not encapsulated and would likely be special order where the
encapsulated stuff should be found readily at home centers.

Pete C.


Terry Dalton wrote:
>
> "Pete C." <aux3@snet.net> wrote in news:41FFE792.52F3A8CD@snet.net:
>
> >
> >
> > Ethan Winer wrote:
> >>
> >> Terry,
> >>
> >> > Does anyone have any thoughts or experience with the differences of
> >> > two
> >> layers vs one thicker layer? <
> >>
> >> If you're asking about laying fiberglass batts *above* the drop
> >> ceiling tiles, it doesn't really matter how you arrive at the total
> >> thickness. Though you don't need or want to use the kind with a paper
> >> facing. Just get plain fiberglass. I'll also mention that 12 inches
> >> is better than using less because it gives that much more bass
> >> trapping.
> >>
> >> --Ethan
> >
> > I'd suggest that while you do not want the kraft paper faced
> > insulation bats, this would be a good application for the plastic
> > "encapsulated" bats. They would be easier to handle and would reduce
> > the tendency to have fiberglass "rain" when you moved a ceiling tile
> > to pull a cable or whatever.
> >
> > Pete C.
> >
>
> When you say bats are you referring to the insulation strips or some other
> form factor of insulation such as squares that adhere to the drop ceiling
> tiles?
>
> Thanks,
> TD

[Ethan Winer]

Terry,

> When you say bats are you referring to the insulation strips or some other
form factor of insulation such as squares that adhere to the drop ceiling
tiles? <

I'm talking about the raw fluffy fiberglass you can get at Home Depot. They
come in plastic bags containing a bunch of separate four-foot pieces, 15
inches wide, in varying thicknesses. I'm recommending the R38 type that's
one foot thick. The idea is to put them *above* the ceiling tiles, laying on
the metal grid. This gives a lot of bass trapping that is hidden and doesn't
impinge in the room since they're above the existing tiles.

--Ethan

[Terry Dalton]

"Ethan Winer" <ethanw at ethanwiner dot com> wrote in
news:zP-dnaTh_qQglZzfRVn-uw@giganews.com:

> Terry,
>
>> When you say bats are you referring to the insulation strips or some
>> other
> form factor of insulation such as squares that adhere to the drop
> ceiling tiles? <
>
> I'm talking about the raw fluffy fiberglass you can get at Home Depot.
> They come in plastic bags containing a bunch of separate four-foot
> pieces, 15 inches wide, in varying thicknesses. I'm recommending the
> R38 type that's one foot thick. The idea is to put them *above* the
> ceiling tiles, laying on the metal grid. This gives a lot of bass
> trapping that is hidden and doesn't impinge in the room since they're
> above the existing tiles.
>
> --Ethan
>
>
>
Does having the paper on the insulation make any difference? Also if I use
R30 over the ceiling tiles should I still insult above that in the floor
cavities and if so is R13 ok for that and paper or non-paper? Thanks for
your help.

TD

[Ethan Winer]

Terry,

> Does having the paper on the insulation make any difference? <

I already explained that earlier. You don't need or want the paper.

> if I use R30 over the ceiling tiles should I still insult above that in
the floor cavities <

I'm afraid I don't know what you're asking. But all you need to do is lay
the batts on top of the metal grid.

--Ethan

[Terry Dalton]

"Ethan Winer" <ethanw at ethanwiner dot com> wrote in news:vKGdndRvasDHx5
_fRVn-sQ@giganews.com:

> Terry,
>
>> Does having the paper on the insulation make any difference? <
>
> I already explained that earlier. You don't need or want the paper.
>
>> if I use R30 over the ceiling tiles should I still insult above that in
> the floor cavities <
>
> I'm afraid I don't know what you're asking. But all you need to do is lay
> the batts on top of the metal grid.
>
> --Ethan
>
>

Here's the problems I've found with this solution so far:

1) I can't find R38 batts that are in plastic bags both Home Depot and 84
lumber never heard of it although they said that you can get plastic on one
side instead of paper on R19 but not in a bag.

2) The manufacturer of the drop ceiling does not recommend putting the
insulation on the ceiling since it will add more weight to the support


Although it has been mentioned not to use the paper insulation I am not
sure if it makes much of a difference especially since I am using the sound
insulated ceiling tiles have a STC rating of 50. So if I were to simply
put a layer of R30 which is 12" into the cavities of the ceiling as planned
along with these sound tiles does anyone have an opinion of the sound
insulation if I were to do it this way or can shed any light on my
questions.

Thanks,
TD

[Ethan Winer]

Terry,

> 1) I can't find R38 batts that are in plastic bags both Home Depot and 84
lumber never heard of it although they said that you can get plastic on one
side instead of paper on R19 but not in a bag. <

It's not sold with each separate piece in a plastic bag! If you go to the
fiberglass section at Home Depot you'll find large plastic bags stuffed with
fiberglass. When you open the bag, the fiberglass expands and all the pieces
pop out. That's all I meant.

> So if I were to simply put a layer of R30 which is 12" into the cavities
of the ceiling <

If by "cavities" you mean the space between the joists, then Yes, that's a
good way to do it. I suggested laying them on the grid only for simplicity.

--Ethan

[Pete C.]

What I specified and provided a link to the Owens corning version of, is
indeed essentially each separate piece in a plastic bag. More
specifically the batts are wrapped on all four sides (ends open since
they're likely to be cut anyway) with plastic. Presumably one wide face
is a solid plastic and the remaining three will have tiny pin holes to
allow moisture to pass.

This "encapsulates" the fiberglass for the most part so that loose
fiberglass particles do not get free from the batts. This means that you
can handle it without gloves or a mask and also means that each time you
pull down ceiling tiles to run cables or whatever, you do not have
fiberglass particles falling into the room.

This product or the equivalent from other brands should be readily
available from HD / Lowe's / building supply places. It is likely
however that you will only find it in the R11 - R19 sizes since the R38
is normally used in unfinished attics where you are typically using
unfaced material.

As far as the location of the batts, if the joist cavities are empty
then it should be installed in them and not resting on the ceiling grid.
If you were to rest it on the ceiling grid I seriously doubt it would be
a weight issue since it would add a few ounces per square foot.


Ethan Winer wrote:
>
> Terry,
>
> > 1) I can't find R38 batts that are in plastic bags both Home Depot and 84
> lumber never heard of it although they said that you can get plastic on one
> side instead of paper on R19 but not in a bag. <
>
> It's not sold with each separate piece in a plastic bag! If you go to the
> fiberglass section at Home Depot you'll find large plastic bags stuffed with
> fiberglass. When you open the bag, the fiberglass expands and all the pieces
> pop out. That's all I meant.
>
> > So if I were to simply put a layer of R30 which is 12" into the cavities
> of the ceiling <
>
> If by "cavities" you mean the space between the joists, then Yes, that's a
> good way to do it. I suggested laying them on the grid only for simplicity.
>
> --Ethan

[Ethan Winer]

Pete,

> What I specified and provided a link to the Owens corning version of, is
indeed essentially each separate piece in a plastic bag. <

Thanks for clarifying. I've never seen fiberglass sold that way, but it's a
great idea!

--Ethan