I need to insulate the attic, and I have some questions/concerns I
hope someone can help me out.

I have 2x6 in the attic, and it is about 80-90% covered with really
old what appears to be unfaced R19 fiberglass batts. It looks very
dirty (I replaced the roof so lots of dust falled on it) and aged.
Some of it is only half the height of the 2x6.

I've gotten some bids, and it is about $1400 for blow-in fiberglass,
and $1100 for blow-in cellulose of R30. All of them said I can leave
what I have up there, and just blow on top of it. (I am in San
Francisco area and the recommended attic is R38)

1) Is it good to blow on top of the old/aged/molded fiberglass? Should
I remove it and start clean? Does it insulate better that way?

2) fiberglass guys claims that cellulose will rot the wiring and
plumbing if it get wet, and will degrade. It is also very dusty which
is a big concern for me. Cellulose guy says fiberglass has health
risks. I have heating duct in the attic, and I am concerned about the
fiberglass, or the cellulose dust being drawn into the duct and gets
everywhere. Fiberglass guy says because my house is relatively old
(1950ish), he wasn't sure if I have tube/wire electrical wire up there
and cellulose is not safe. The cellulose guy said I don't need to
worry about it.

I am thinking about replacing the fiberglass wrapping around my
heating duct with more modern ones to seal off any gaps before I blow
the insulation up there. Right now I am leaning toward fiberglass as
it won't age or settle, and if I get a roof leak it won't get
destroyed. But how do I know if the installer won't fluff the blow-in?

3) The cellulose guy quoted me 8.1" for R30. I just don't like that
8.1". I mean how the hell is he going to make sure that the attic is
8.1, not 8, or 7.5? by eye balling it? Seems like I am paying by the
inch yet I have no easy way of verifying it. (I can't really walk in
the attic after it's done..) One of the fiberglass guy said they've
done this for so long, that they just know if it's 12" or not. Is it
true? Or do they basically do "ah, it looks like 12", done, when in
fact, it may very well be just 10")

Which weights more? Cellulose or fiberglass? If I go with R38 (doesn't
add that much to the cost), Is the weight of all that insulation cause
any problem with the ceiling in the long run?

Thanks!

Raymond

Cellulose is the only way to go. Attics or walls. It's fire retardant, and
has more r value per inch. And there's no reason for it to get wet, but if
it does, it just dries out. As a matter of fact, it is applied wet.

check out www.centralfiber.com


--
Steve Barker




wrote in message
...

I need to insulate the attic, and I have some questions/concerns I
hope someone can help me out.

I have 2x6 in the attic, and it is about 80-90% covered with really
old what appears to be unfaced R19 fiberglass batts. It looks very
dirty (I replaced the roof so lots of dust falled on it) and aged.
Some of it is only half the height of the 2x6.

I've gotten some bids, and it is about $1400 for blow-in fiberglass,
and $1100 for blow-in cellulose of R30. All of them said I can leave
what I have up there, and just blow on top of it. (I am in San
Francisco area and the recommended attic is R38)

1) Is it good to blow on top of the old/aged/molded fiberglass? Should
I remove it and start clean? Does it insulate better that way?

2) fiberglass guys claims that cellulose will rot the wiring and
plumbing if it get wet, and will degrade. It is also very dusty which
is a big concern for me. Cellulose guy says fiberglass has health
risks. I have heating duct in the attic, and I am concerned about the
fiberglass, or the cellulose dust being drawn into the duct and gets
everywhere. Fiberglass guy says because my house is relatively old
(1950ish), he wasn't sure if I have tube/wire electrical wire up there
and cellulose is not safe. The cellulose guy said I don't need to
worry about it.

I am thinking about replacing the fiberglass wrapping around my
heating duct with more modern ones to seal off any gaps before I blow
the insulation up there. Right now I am leaning toward fiberglass as
it won't age or settle, and if I get a roof leak it won't get
destroyed. But how do I know if the installer won't fluff the blow-in?

3) The cellulose guy quoted me 8.1" for R30. I just don't like that
8.1". I mean how the hell is he going to make sure that the attic is
8.1, not 8, or 7.5? by eye balling it? Seems like I am paying by the
inch yet I have no easy way of verifying it. (I can't really walk in
the attic after it's done..) One of the fiberglass guy said they've
done this for so long, that they just know if it's 12" or not. Is it
true? Or do they basically do "ah, it looks like 12", done, when in
fact, it may very well be just 10")

Which weights more? Cellulose or fiberglass? If I go with R38 (doesn't
add that much to the cost), Is the weight of all that insulation cause
any problem with the ceiling in the long run?

Thanks!

Raymond

wrote:
I need to insulate the attic, and I have some questions/concerns I
hope someone can help me out.


Both are fine.

Beware of any contractor who knocks the other product.

I would choose the cellulose as it does have some advantages that I
believe are worthwhile.

--
Joseph Meehan

Dia 's Muire duit

"Steve Barker" wrote in message
...
Cellulose is the only way to go. Attics or walls. It's fire retardant,
and
has more r value per inch. And there's no reason for it to get wet, but
if
it does, it just dries out. As a matter of fact, it is applied wet.

I've never seen it applied wet.

Bob

wrote in message
...

I need to insulate the attic, and I have some questions/concerns I
hope someone can help me out.

I have 2x6 in the attic, and it is about 80-90% covered with really
old what appears to be unfaced R19 fiberglass batts. It looks very
dirty (I replaced the roof so lots of dust falled on it) and aged.
Some of it is only half the height of the 2x6.

I've gotten some bids, and it is about $1400 for blow-in fiberglass,
and $1100 for blow-in cellulose of R30. All of them said I can leave
what I have up there, and just blow on top of it. (I am in San
Francisco area and the recommended attic is R38)

I just bought unfaced batts and put them in myself. It only took an
afternoon.

Bob

In alt.home.repair Bob F wrote:

I just bought unfaced batts and put them in myself. It only took an
afternoon.

Well I've been thinking about that too, but at my local HD, the cost
of the batt is about $0.94 per sq ft, that's about $1400 for my
1400sqft home. Plus that's a lot of material to haul. I calculated 30
bags. Do you have a truck?

Raymond

On Mar 2, 2:28 pm, wrote:
In alt.home.repair Bob F wrote:

I just bought unfaced batts and put them in myself. It only took an
afternoon.

Well I've been thinking about that too, but at my local HD, the cost
of the batt is about $0.94 per sq ft, that's about $1400 for my
1400sqft home. Plus that's a lot of material to haul. I calculated 30
bags. Do you have a truck?

Raymond

I'd go with fiberglass batts too. That helps address your concern
about fiberglass getting into the A/C system. When it's in batts,
that's less of an issue as opposed to blowing stuff around all over
the place. Also, whatever you do, if you have soffit vents, make sure
they don't get blocked. If you don't have baffles in place, I'd put
them in before the insulation.

On Mar 2, 2:59 pm, wrote:
On Mar 2, 2:28 pm, wrote:

In alt.home.repair Bob F wrote:

I just bought unfaced batts and put them in myself. It only took an
afternoon.

Well I've been thinking about that too, but at my local HD, the cost
of the batt is about $0.94 per sq ft, that's about $1400 for my
1400sqft home. Plus that's a lot of material to haul. I calculated 30
bags. Do you have a truck?

Raymond

I'd go with fiberglass batts too. That helps address your concern
about fiberglass getting into the A/C system. When it's in batts,
that's less of an issue as opposed to blowing stuff around all over
the place. Also, whatever you do, if you have soffit vents, make sure
they don't get blocked. If you don't have baffles in place, I'd put
them in before the insulation.

Oh, and you also said one contractor said you might have k n tube
wiring? Shouldn't be, if the house is only from the 50's. But I'd
figure that out first. Not sure I'd put anything on top of k n tube,
because if it's there, sooner or later you'll have to address that and
if you bury it in insulation, it just makes the rewire harder.

On Mar 1, 4:03 pm, wrote:
dirty (I replaced the roof so lots of dust falled on it) and aged.

Don't worry about it, the attic is going to be a dirty place after all
these years. It should always be ventilated to the outside anyway.
Dirt won't affect the R-value.

1) Is it good to blow on top of the old/aged/molded fiberglass? Should
I remove it and start clean? Does it insulate better that way?

It won't insulate better than if you had all new fluffy insulation to
the final height, but so what, you can always blow extra. Are they
going to charge you for the final height, or just the addition? It
isn't practical to remove te old stuff, there's decades worth of dust
that'll ve kicked up. You hhave to wear a breathing filter even in a
settled attic, so this'll be a nightmare.

risks. I have heating duct in the attic, and I am concerned about the
fiberglass, or the cellulose dust being drawn into the duct and gets

Is it supply or return? A supply is at positive pressure, so nothing
is getting drawn in unless there are holes (not likely).

everywhere. Fiberglass guy says because my house is relatively old
(1950ish), he wasn't sure if I have tube/wire electrical wire up there

Look into what you have. As another poster has mentioned, it is a good
time to upgrade wiring before you blow more insulation, if indeed it
needs upgrading. If it is conduit, you can upgrade wiring from the
inside of the house.

I am thinking about replacing the fiberglass wrapping around my
heating duct with more modern ones to seal off any gaps before I blow
the insulation up there.

Oh, you're willing to do some work yourself! In that case, take a can
of expanding foam such as Great Stuff! up there and lay a bead around
electrical box openings in the ceiling. Wear a nose mask.

You should also give consideration to blowing cellulose in yourself.
1400 sq ft is about 1.5 hours of actual blowing. You'll need a couple
of helpers, but you can blow as much as you want, and it is fun!

It's applied wet in the unfinished walls. Otherwise, it would all be on the
floor. And my job also included a wet application in the attic, because it
then becomes what they call "stabilized" and won't blow around when I turn
on that massive whole house fan. I gave it a full two weeks to dry before
covering the walls.

--
Steve Barker




"Bob F" wrote in message
. ..

"Steve Barker" wrote in message
...
Cellulose is the only way to go. Attics or walls. It's fire retardant,
and
has more r value per inch. And there's no reason for it to get wet, but
if
it does, it just dries out. As a matter of fact, it is applied wet.

I've never seen it applied wet.

Bob

Knob and tube was used up into the late '50's in the rural areas.

--
Steve Barker




wrote in message
oups.com...
Oh, and you also said one contractor said you might have k n tube
wiring? Shouldn't be, if the house is only from the 50's. But I'd
figure that out first. Not sure I'd put anything on top of k n tube,
because if it's there, sooner or later you'll have to address that and
if you bury it in insulation, it just makes the rewire harder.

I just talked to one of the gurus of accurateBuilding.com who also
show up at the Leonard Loped show on WNYC every month. I told Al that
I consider to put cellulose into my walls. He said don't use
cellulose, because the additives can have some negative effects;
especially if then not evenly distributed. The copper sulfides (Ithink
for fire retardent) might corrode the nails that get in touch with the
insulation and he was suspicious about the fungicides.

He recommended:
* Mineral wool
* Fiberglas
* Perlites

I heard good things about perlites, which don't need additives and
doesn't have issues with moisture, rodents, and is very fire
retardent. So I am looking into that. What I heard is that you can
just poor it in.

Does anybody has experience with using perlites (or vermiculites (same
category of material)) for insulation?

Thanks,
Wilko

The stuff I have doesn't have copper sulfides. It uses boric acid, which is
also a good pest repellant. check out

www.centralfiber.com


--
Steve Barker




"Esche" wrote in message
ps.com...

I just talked to one of the gurus of accurateBuilding.com who also
show up at the Leonard Loped show on WNYC every month. I told Al that
I consider to put cellulose into my walls. He said don't use
cellulose, because the additives can have some negative effects;
especially if then not evenly distributed. The copper sulfides (Ithink
for fire retardent) might corrode the nails that get in touch with the
insulation and he was suspicious about the fungicides.

He recommended:
* Mineral wool
* Fiberglas
* Perlites

I heard good things about perlites, which don't need additives and
doesn't have issues with moisture, rodents, and is very fire
retardent. So I am looking into that. What I heard is that you can
just poor it in.

Does anybody has experience with using perlites (or vermiculites (same
category of material)) for insulation?

Thanks,
Wilko

wrote in message
2) fiberglass guys claims that cellulose will rot the wiring and
plumbing if it get wet, and will degrade. It is also very dusty which
is a big concern for me. Cellulose guy says fiberglass has health
risks. I have heating duct in the attic, and I am concerned about the
fiberglass, or the cellulose dust being drawn into the duct and gets
everywhere. Fiberglass guy says because my house is relatively old
(1950ish), he wasn't sure if I have tube/wire electrical wire up there
and cellulose is not safe. The cellulose guy said I don't need to
worry about it.

If you have knob&tube wiring, you don't want to insulate the
wiring. It won't meet code.

Bob

On Fri, 2 Mar 2007 19:28:23 +0000 (UTC), someone wrote:

.... Plus that's a lot of material to haul. I calculated 30
bags. Do you have a truck?

My local (non-HD) yard offers free local delivery. This is the same
yard that does a huge business with all the home builders in the area
so there is always a delivery going to my area in the next day or so.
Or all the HDs in my region rent trucks by the hour for DIYers to haul
the stuff home; I presume they do that in most/all areas?

Don't let the mere delivery throw you. You also DON'T HAVE TO BUY/DO
IT ALL AT ONCE! Heck, do six bags each day (or week) if ya wanna.



Reply to NG only - this e.mail address goes to a kill file.

On Thu, 1 Mar 2007 22:03:37 +0000 (UTC), someone wrote:

3) The cellulose guy quoted me 8.1" for R30. I just don't like that
8.1". I mean how the hell is he going to make sure that the attic is
8.1, not 8, or 7.5? by eye balling it?

Don't be so anal.

You pay for the needed volume to put the needed depth over the area in
question. It all goes in. So what if you eyeball whether it is
level, it will still ON AVERAGE be the specified depth, and if one
spot is 1/2 inch low than another spot will be a 1/2 inch high. So
what.

Don't try to cut it so fine.


Reply to NG only - this e.mail address goes to a kill file.

On Sun, 04 Mar 2007 17:29:33 GMT, (v) wrote:

On Thu, 1 Mar 2007 22:03:37 +0000 (UTC), someone wrote:

3) The cellulose guy quoted me 8.1" for R30. I just don't like that
8.1". I mean how the hell is he going to make sure that the attic is
8.1, not 8, or 7.5? by eye balling it?

Don't be so anal.

You pay for the needed volume to put the needed depth over the area in
question. It all goes in. So what if you eyeball whether it is
level, it will still ON AVERAGE be the specified depth, and if one
spot is 1/2 inch low than another spot will be a 1/2 inch high. So
what.

Don't try to cut it so fine.


Reply to NG only - this e.mail address goes to a kill file.


Very true, I think if you want R30, you should aim higher. Also, I
was told it's average thing, some areas will be higher, while others
might be lower.

Just what I was told....

tom @ www.FatHubby.com