Vapor barriers in attic floor insulation

[Guest guest]

Company is proposing insulation in attic floor. I like the encased in poly

johns manfield that I posted here. It has a vapor barrier on one side. I'm

concerned about where vapor barrier is put. It says facing the interior. s

Manfield said we can only use one layer of the poly encased due to it have pin

holes that can't be obstructed so if we use more than one layer, the other layer

has to be something else. Proposal is for unfaced fiberglass to be between the

floor joists and the polyencased on top of that, going the other direction.

That seems fine except for one thing. With the poly encased on top, that means

the vapor barrier is not against the attic floor. Installer said s Manfield

technical people were consulted *because it is a new product for them and they

said this was okay installation. Does that sound okay to people here? So if

there is any warm moist air leaking from house, it will go through unfaced

fiberglass and be stopped by vapor barrier 6-10 inches above it, depending on

the depth we chose. There shouldn't be a leak since it is air sealed but a leak

could develop in the future, settling of house, cracked plaster, etc or

something that should have been air sealed but was not. It doesn't sound right

to me but they said they discussed w JM tech people.

[Guest guest]

Why did they say they weren’t doing

it the other way around, faced down first covered by the unfaced? That would

seem to solve your concern and I am not seeing any advantage to the installers

one way over the other.

Shell Bleiweiss

Law Offices of Shell J. Bleiweiss

Environmental and OSHA Law

Offices in Chicago

and Barrington, Illinois

sbleiweiss@...

http://www.shell-bleiweiss.com

From:

iequality [mailto:iequality ] On Behalf Of barb b w

Sent: Thursday, January 12, 2012

2:25 PM

To: iequality

Subject: Vapor

barriers in attic floor insulation

Company is proposing insulation in attic floor. I like

the encased in poly johns manfield that I posted here. It has a vapor barrier

on one side. I'm concerned about where vapor barrier is put. It says facing the

interior. s Manfield said we can only use one layer of the poly encased due

to it have pin holes that can't be obstructed so if we use more than one layer,

the other layer has to be something else. Proposal is for unfaced fiberglass to

be between the floor joists and the polyencased on top of that, going the other

direction. That seems fine except for one thing. With the poly encased on top,

that means the vapor barrier is not against the attic floor. Installer said

s Manfield technical people were consulted *because it is a new product for

them and they said this was okay installation. Does that sound okay to people

here? So if there is any warm moist air leaking from house, it will go through

unfaced fiberglass and be stopped by vapor ba rrier 6-10 inches above it,

depending on the depth we chose. There shouldn't be a leak since it is air

sealed but a leak could develop in the future, settling of house, cracked

plaster, etc or something that should have been air sealed but was not. It

doesn't sound right to me but they said they discussed w JM tech people.

[Guest guest]

The vapour barrier should be on a specific side relevant to the source of vapour or dew point.In cooling climate such as Texas warm air in the untreated loft would touch the cooler insulation. Dew Point would occur and if the vapour barrier was on the top no problem. If it were at the bottom the insulation may become saturated.More importantly in a heating climate such as Canada warm air would rise from the rooms to the loft and cold air in the untreated loft space would come in contact causing Dew Point on the cold side of the warm insulation.Hope this helps.Jeff From: iequality [mailto:iequality ] On Behalf Of Shell BleiweissSent: 12 January 2012 22:25To: iequality Subject: RE: Vapor barriers in attic floor insulation Why did they say they weren’t doing it the other way around, faced down first covered by the unfaced? That would seem to solve your concern and I am not seeing any advantage to the installers one way over the other. Shell BleiweissLaw Offices of Shell J. BleiweissEnvironmental and OSHA LawOffices in Chicago and Barrington, Illinois sbleiweiss@...http://www.shell-bleiweiss.com From: iequality [mailto:iequality ] On Behalf Of barb b wSent: Thursday, January 12, 2012 2:25 PMTo: iequality Subject: Vapor barriers in attic floor insulation Company is proposing insulation in attic floor. I like the encased in poly johns manfield that I posted here. It has a vapor barrier on one side. I'm concerned about where vapor barrier is put. It says facing the interior. s Manfield said we can only use one layer of the poly encased due to it have pin holes that can't be obstructed so if we use more than one layer, the other layer has to be something else. Proposal is for unfaced fiberglass to be between the floor joists and the polyencased on top of that, going the other direction. That seems fine except for one thing. With the poly encased on top, that means the vapor barrier is not against the attic floor. Installer said s Manfield technical people were consulted *because it is a new product for them and they said this was okay installation. Does that sound okay to people here? So if there is any warm moist air leaking from house, it will go through unfaced fiberglass and be stopped by vapor ba rrier 6-10 inches above it, depending on the depth we chose. There shouldn't be a leak since it is air sealed but a leak could develop in the future, settling of house, cracked plaster, etc or something that should have been air sealed but was not. It doesn't sound right to me but they said they discussed w JM tech people.

[Guest guest]

I didn't want blown in bec I didn't want to add particulate to the air so we

decided on the encased batts, two layers but then found they don't recommend two

layers of encased batts because they have air holes in them and the second layer

would not let the first layer breathe, so we went with first layer unencased and

top layer encased because, my idea, it would keep the top layer clean over time.

That was planned but then I questioned if the vapor barrier would be okay 6

inches above the floor since instructions say to put it next to the interior

wall. Their contact said it would be okay, my contact with company tech rep

said no it wouldn't be. Then there is a picture of it being used that way in

their own brochure. It shows it being rolled on top of cellulose down in betw

the floor joists. After a lot of back in forth, s Manfield said it is

better to be the first layer but the second layer would be okay if vapor barrier

is facing down since there is another layer of insulation *on top of it, so

that's how it has ended. To me, over the years dirt landing on the poly

encapsulated product would be less conducive to growing mold than unencased

fiberglass that has become dirty over the years.

>

> Why did they say they weren't doing it the other way around, faced down

> first covered by the unfaced? That would seem to solve your concern and I am

> not seeing any advantage to the installers one way over the other.

>

>

>

> Shell Bleiweiss

[Guest guest]

I don’t think you answered my

question. JM says best if vapor barrier is first layer, so why not do it that

way?

Shell Bleiweiss

Law Offices of Shell J. Bleiweiss

Environmental and OSHA Law

Offices in Chicago

and Barrington, Illinois

sbleiweiss@...

http://www.shell-bleiweiss.com

From: iequality [mailto:iequality ] On Behalf Of barb b w

Sent: Sunday, January 15, 2012

10:34 AM

To: iequality

Subject: Re: Vapor

barriers in attic floor insulation

I didn't want blown in bec I didn't want to add

particulate to the air so we decided on the encased batts, two layers but then

found they don't recommend two layers of encased batts because they have air

holes in them and the second layer would not let the first layer breathe, so we

went with first layer unencased and top layer encased because, my idea, it

would keep the top layer clean over time. That was planned but then I

questioned if the vapor barrier would be okay 6 inches above the floor since

instructions say to put it next to the interior wall. Their contact said it

would be okay, my contact with company tech rep said no it wouldn't be. Then

there is a picture of it being used that way in their own brochure. It shows it

being rolled on top of cellulose down in betw the floor joists. After a lot of

back in forth, s Manfield said it is better to be the first layer but the

second layer would be okay if vapor barrier is facing down since there is

anothe r layer of insulation *on top of it, so that's how it has ended. To me,

over the years dirt landing on the poly encapsulated product would be less

conducive to growing mold than unencased fiberglass that has become dirty over

the years.

>

> Why did they say they weren't doing it the other way around, faced down

> first covered by the unfaced? That would seem to solve your concern and I

am

> not seeing any advantage to the installers one way over the other.

>

>

>

> Shell Bleiweiss

[Guest guest]

JM said it can be done either way, best is first layer; but second layer is okay

as long as there is insulation on top of it as there will be. If had to start

over again, I think I would put encased w vapor barrier as first layer and loose

cellulose over the top but materials are already ordered. The materials are

unfaced fiberglass batts and encased fiberglass batts. I think with the encased

fiberglass over the top with vapor barrier down will keep unfaced fiberglass

from becoming full of dirt which then make a haven for mold and microbes,

whereas the encased on top will keep that open unfaced, unencased clean as an

underlayer. From what I have observed, unfaced, unencased fiberglass batts

after being exposed to heat and humidity that may be present in attic over time,

become brittle and degrade. I think the encased over the top will prevent that

but perhaps the encased will deteriorate in time too. They say the encasement

is more for undusty installation so I don't know how long encasing holds up.

It's a crap shoot, excuse the language. There seems to be no good choices as

far as I'm concerned. They said the only problem installation is vapor barrier

up where cold air could hit it. They aren't going to start installing it until

tomorrow or Wednesday so I could reverse it. Loose cellulose over the top I

would prefer over unfaced fiberglass as I don't like the idea of airborne

fiberglass even in the attic and unfaced would do that when walked on by anyone

trying to move around up there.

>

> I don't think you answered my question. JM says best if vapor barrier is

> first layer, so why not do it that way?

>

>

>

> Shell Bleiweiss

>

> Law Offices of Shell J. Bleiweiss

>

> Environmental and OSHA Law

>

> Offices in Chicago and Barrington, Illinois

>

>

>

> sbleiweiss@...

>

> http://www.shell-bleiweiss.com <http://www.shell-bleiweiss.com/>

>

[Guest guest]

Either way there will be fiberglass

insulation exposed at the upper surface which people will step on if walking

around up there. I would put faced down first followed by unfaced. BTW, with a

second layer of batt insulation rolled over the joists (I think horizontal ones

may be called something else but can’t think of the term at the moment)

perpendicular to the joists, how can someone know where to put there feet down

to walk over the top?

Shell Bleiweiss

Law Offices of Shell J. Bleiweiss

Environmental and OSHA Law

Offices in Chicago

and Barrington, Illinois

sbleiweiss@...

http://www.shell-bleiweiss.com

From: iequality [mailto:iequality ] On Behalf Of barb b w

Sent: Monday, January 16, 2012

11:52 AM

To: iequality

Subject: Re: Vapor

barriers in attic floor insulation

JM said it can be done either way, best is first

layer; but second layer is okay as long as there is insulation on top of it as

there will be. If had to start over again, I think I would put encased w vapor

barrier as first layer and loose cellulose over the top but materials are

already ordered. The materials are unfaced fiberglass batts and encased

fiberglass batts. I think with the encased fiberglass over the top with vapor

barrier down will keep unfaced fiberglass from becoming full of dirt which then

make a haven for mold and microbes, whereas the encased on top will keep that

open unfaced, unencased clean as an underlayer. From what I have observed,

unfaced, unencased fiberglass batts after being exposed to heat and humidity

that may be present in attic over time, become brittle and degrade. I think the

encased over the top will prevent that but perhaps the encased will deteriorate

in time too. They say the encasement is more for undusty installation so I

don't know how long encasing holds up. It's a crap shoot, excuse the language.

There seems to be no good choices as far as I'm concerned. They said the only

problem installation is vapor barrier up where cold air could hit it. They

aren't going to start installing it until tomorrow or Wednesday so I could

reverse it. Loose cellulose over the top I would prefer over unfaced fiberglass

as I don't like the idea of airborne fiberglass even in the attic and unfaced

would do that when walked on by anyone trying to move around up there.

>

> I don't think you answered my question. JM says best if vapor barrier is

> first layer, so why not do it that way?

>

>

>

> Shell Bleiweiss

>

> Law Offices of Shell J. Bleiweiss

>

> Environmental and OSHA Law

>

> Offices in Chicago and Barrington, Illinois

>

>

>

> sbleiweiss@...

>

> http://www.shell-bleiweiss.com

<http://www.shell-bleiweiss.com/>

>

[Guest guest]

If the attic is not used as an extra room in the house, then we can assume that there is no floor on the joists. If that is true, then when a person has to go into the attic for inspection or repair, that individual must have a sturdy support and know where to put the knee or foot. If the joist is covered with insulation, it is hidden and will subject the person up there to accidentally rupturing the ceiling and even falling through. My electrician uncle fell through the ceiling on a job he was working on and broke his back. The bottom line is to never cover the joists with anything that will hide them. Norm Gauss From: iequality [mailto:iequality ] On Behalf Of Shell BleiweissSent: Monday, January 16, 2012 10:56 AMTo: iequality Subject: RE: Re: Vapor barriers in attic floor insulation Either way there will be fiberglass insulation exposed at the upper surface which people will step on if walking around up there. I would put faced down first followed by unfaced. BTW, with a second layer of batt insulation rolled over the joists (I think horizontal ones may be called something else but can’t think of the term at the moment) perpendicular to the joists, how can someone know where to put there feet down to walk over the top? Shell BleiweissLaw Offices of Shell J. BleiweissEnvironmental and OSHA LawOffices in Chicago and Barrington, Illinois sbleiweiss@...http://www.shell-bleiweiss.com From: iequality [mailto:iequality ] On Behalf Of barb b wSent: Monday, January 16, 2012 11:52 AMTo: iequality Subject: Re: Vapor barriers in attic floor insulation JM said it can be done either way, best is first layer; but second layer is okay as long as there is insulation on top of it as there will be. If had to start over again, I think I would put encased w vapor barrier as first layer and loose cellulose over the top but materials are already ordered. The materials are unfaced fiberglass batts and encased fiberglass batts. I think with the encased fiberglass over the top with vapor barrier down will keep unfaced fiberglass from becoming full of dirt which then make a haven for mold and microbes, whereas the encased on top will keep that open unfaced, unencased clean as an underlayer. From what I have observed, unfaced, unencased fiberglass batts after being exposed to heat and humidity that may be present in attic over time, become brittle and degrade. I think the encased over the top will prevent that but perhaps the encased will deteriorate in time too. They say the encasement is more for undusty installation so I don't know how long encasing holds up. It's a crap shoot, excuse the language. There seems to be no good choices as far as I'm concerned. They said the only problem installation is vapor barrier up where cold air could hit it. They aren't going to start installing it until tomorrow or Wednesday so I could reverse it. Loose cellulose over the top I would prefer over unfaced fiberglass as I don't like the idea of airborne fiberglass even in the attic and unfaced would do that when walked on by anyone trying to move around up there. >> I don't think you answered my question. JM says best if vapor barrier is> first layer, so why not do it that way?> > > > Shell Bleiweiss> > Law Offices of Shell J. Bleiweiss> > Environmental and OSHA Law> > Offices in Chicago and Barrington, Illinois> > > > sbleiweiss@...> > http://www.shell-bleiweiss.com <http://www.shell-bleiweiss.com/> >

[Guest guest]

I ALWAYS ask this question Shell, how do you walk up there then? They say not to go up there, but that's not realistic. I had a cat walk put up there yesterday the length of the attic that follows the top board of the roof line so I can confidently tell people they can walk down the center without falling through. It's about 20 inches wide. If they need to go to the sides, they will have to follow the rafters I'm told. BTW, with a

second layer of batt insulation rolled over the joists (I think horizontal ones

may be called something else but can’t think of the term at the moment)

perpendicular to the joists, how can someone know where to put there feet down

to walk over the top?

Shell Bleiweiss Law Offices of Shell J. Bleiweiss Environmental and OSHA Law Offices in Chicago and Barrington , Illinois sbleiweiss@... http://www.shell-bleiweiss.com

[Guest guest]

I humbly disagree with the advice about never covering joists. Blown insulation will cover all the joists, increasing their approximate R-value from 3 or 4 to several

times that depending on the type of insulation installed. Batts installed to cover the joists will have a similar effect. I am very sorry to hear your uncle was injured however I inspected attics daily for 6 years - all with covered joists – and never fell

through the ceiling or off the joists. In a mild climate such as here in California not covering the joists isn’t that big a deal. But in a cold climate like in Wisconsin the ceiling can develop ghosting due to the thin strips of low R value created by uncovered

joists.

Bill Holloway

From: iequality [mailto:iequality ]

On Behalf Of Norman Gauss

Sent: Wednesday, January 18, 2012 12:29 PM

To: iequality

Subject: RE: Re: Vapor barriers in attic floor insulation

If the attic is not used as an extra room in the house, then we can assume that there is no floor on the joists. If that is true, then

when a person has to go into the attic for inspection or repair, that individual must have a sturdy support and know where to put the knee or foot. If the joist is covered with insulation, it is hidden and will subject the person up there to accidentally

rupturing the ceiling and even falling through. My electrician uncle fell through the ceiling on a job he was working on and broke his back. The bottom line is to never cover the joists with anything that will hide them.

Norm Gauss

From:

iequality

[mailto:iequality ] On Behalf Of Shell Bleiweiss

Sent: Monday, January 16, 2012 10:56 AM

To: iequality

Subject: RE: Re: Vapor barriers in attic floor insulation

Either way there will be fiberglass insulation exposed at the upper surface which people will step on if walking around up there. I would

put faced down first followed by unfaced. BTW, with a second layer of batt insulation rolled over the joists (I think horizontal ones may be called something else but can’t think of the term at the mom! ent) perpendicular to the joists, how can someone know

where to put there feet down to walk over the top?

Shell Bleiweiss

Law Offices of Shell J. Bleiweiss

Environmental and OSHA Law

Offices in Chicago and Barrington, Illinois

sbleiweiss@...

http://www.shell-bleiweiss.com

From:

iequality

[mailto:iequality ] On Behalf Of barb b w

Sent: Monday, January 16, 2012 11:52 AM

To: iequality

Subject: Re: Vapor barriers in attic floor insulation

JM said it can be done either way, best is first layer; but second layer is! okay as ! long as there is insulation on top of it as there will be. If had to start over again, I think I would put encased w vapor barrier as first layer and loose cellulose over

the top but materials are already ordered. The materials are unfaced fiberglass batts and encased fiberglass batts. I think with the encased fiberglass over the top with vapor barrier down will keep unfaced fiberglass from becoming full of dirt which then

make a haven for mold and microbes, whereas the encased on top will keep that open unfaced, unencased clean as an underlayer. From what I have observed, unfaced, unencased fiberglass batts after being exposed to heat and humidity that may be present in attic

over time, become brittle and degrade. I think the encased over the top will prevent that but perhaps the encased will deteriorate in time too. They say the encasement is more for undusty installation so I don't know how long encasing holds up. It's a crap

shoot, excuse the language. There seems to be no good choices as far as I'm concerned. They said the only problem installation is vapor barrier up where cold air could hit it. They aren't going to start installing it until tomorrow or Wednesday so I could

reverse it. Loose cellulose over the top I would prefer over unfaced fiberglass as I don't like the idea of airborne fiberglass even in the attic and unfaced would do that when walked on by anyone trying to move around up there.

>

> I don't think you answered my question. JM says best if vapor barrier is

> first layer, so why not do it that way?

>

>

>

> Shell Bleiweiss

>

> Law Offices of Shell J. Bleiweiss

>

> Environmental and OSHA Law

>

> Offices in Chicago and Barrington, Illinois

>

>

>

> sbleiweiss@...

>

> http://www.shell-bleiweiss.com <http://www.shell-bleiweiss.com/>

>

[Guest guest]

I wanted them to insulate the underside of the roof instead but they said that is not recommended in this climate zone. I think that is changing but for now all I could get was floor. If I do just to top of joist it will be only 6 inches of insulation and I cannot get the local energy association to pay part unless I bring it up to R38. I put the cat walk in and then I will get a couple of boards. The joists are 15 inches apart so if you have a board that spans more than that, it is pretty safe. A person has to put the board down, looking up at the rafters as guides and scoot around. With the cat walk they should be okay walking the length of the attic, and I also added two pull chain lights to attic ceiling. I agree it's an important topic. Everyone just said "don't go up there"...I guess they meant *me but

I'm worried about other people too. Just because workers carry insurance doesn't mean it's okay if they have an accident.Subject: RE: Re: Vapor barriers in attic floor insulationTo: iequality Date: Wednesday, January 18, 2012, 3:28 PM

If the attic is not used as an extra room in the house, then we can assume that there is no floor on the joists. If that is true, then when a person has to go into the attic for inspection or repair, that individual must have a sturdy support and know where to put the knee or foot. If the joist is covered with insulation, it is hidden and will subject the person up there to accidentally rupturing the ceiling and even falling through. My electrician uncle fell through the ceiling on a job he was working on and broke his back. The bottom line is to never cover the joists with anything that will hide them.

[Guest guest]

On the top layer the insulation is encased in plastic so it wasn't going to be exposed fiberglass. Anyway, the whole thing has changed now. I'm going to put an undate on the s Manfield product so other people have more information about it. Either way there

will be fiberglass

insulation exposed at the upper surface which people will step on if walking

around up there. I would put faced down first followed by unfaced.

[Guest guest]

Yes, I didn't want the joints covered but with six inches only to top of joists, I couldn't get the required minimum R value. I live in the midwest. It's in the 20's this week. I humbly disagree with the advice about never covering joists. Blown insulation will cover all the joists, increasing their approximate R-value from 3 or 4 to several

times that depending on the type of insulation installed. Batts installed to cover the joists will have a similar effect. I am very sorry to hear your uncle was injured however I inspected attics daily for 6 years - all with covered joists – and never fell

through the ceiling or off the joists. In a mild climate such as here in California not covering the joists isn’t that big a deal. But in a cold climate like in Wisconsin the ceiling can develop ghosting due to the thin strips of low R value created by uncovered

joists.

[Guest guest]

Bill: What is the technique for walking on joists that are hidden by insulation? Do you take two 1 x 12 boards that are about 4 ft long and lay them across the joists end-to-end in the general direction toward which you are moving? If this is done, the insulation will be mashed down. Would this be bad for the insulation? Norm Gauss From: iequality [mailto:iequality ] On Behalf Of Holloway, BillSent: Wednesday, January 18, 2012 12:45 PMTo: iequality Subject: RE: Re: Vapor barriers in attic floor insulation I humbly disagree with the advice about never covering joists. Blown insulation will cover all the joists, increasing their approximate R-value from 3 or 4 to several times that depending on the type of insulation installed. Batts installed to cover the joists will have a similar effect. I am very sorry to hear your uncle was injured however I inspected attics daily for 6 years - all with covered joists – and never fell through the ceiling or off the joists. In a mild climate such as here in California not covering the joists isn’t that big a deal. But in a cold climate like in Wisconsin the ceiling can develop ghosting due to the thin strips of low R value created by uncovered joists. Bill Holloway_,___

[Guest guest]

Hi, all--

Forgive me if I missed it in this thread, but I didn't see any comments about

the placement of the vapor retarder ( " barrier " is considered inaccurate

terminology). It should be installed so it is located at the ceiling, in order

to avoid or minimize potential condensation of water vapor that is transported

along with air leaking through openings in the ceiling.

In general it's good practice to seal air leaks while they are visible and and

accessible, before installing insulation. Often the air leaks cause more heat

loss than conductivity does.

Best,

Mike O'Brien

> I humbly disagree with the advice about never covering joists.  Blown

insulation will cover all the joists, increasing their approximate R-value from

3 or 4 to several

> times that depending on the type of insulation installed.  Batts installed

to cover the joists will have a similar effect.  I am very sorry to hear your

uncle was injured however I inspected attics daily for 6 years - all with

covered joists †" and never fell

> through the ceiling or off the joists.  In a mild climate such as here in

California not covering the joists isn’t that big a deal.  But in a cold

climate like in Wisconsin the ceiling can develop ghosting due to the thin

strips of low R value created by uncovered

> joists.

>

[Guest guest]

Thanks. Yes, the s Manfield product that is poly wrapped fiberglass batting comes with a vapor retarder and not a barrier on one side and they said it should go against an interior wall or ceiling. For hot, humid climate areas, i.e. Florida, etc, they have same product with no vapor retarder. It has tiny pin holes in the poly wrap but I discovered it is not really 'encased' as it is described as the ends are completely exposed fiberglass batting, so it is poly-wrapped, not encased.Hi, all--

Forgive me if I missed it in this thread, but I didn't see any comments about the placement of the vapor retarder ("barrier" is considered inaccurate terminology). It should be installed so it is located at the ceiling, in order to avoid or minimize potential condensation of water vapor that is transported along with air leaking through openings in the ceiling.

In general it's good practice to seal air leaks while they are visible and and accessible, before installing insulation. Often the air leaks cause more heat loss than conductivity does.

[Guest guest]

Hi Norm

When inspecting we didn’t have to walk on every joist of course. We did have to reach a point/locations in an attic that allowed visual inspection of any area that

contained heat producing devices – this was long before B vent was mandatory or IC recessed lites were produced – as well as establishing the depth/R value of the newly installed insulation.

At first it was thought that the disturbed areas would have a significant effect on the total insulation value. But when we did the math there wasn’t enough square

foot of insulation disturbed to have a genuine and quantifiable effect to the heating or cooling bill. Mathmatically there was a value but it is actually so small that other variables (t-stat settings, doors left open, etc.) were much more important.

As to the technique for staying on the joists I would hold on to the rafter and sweep my foot over where I thought the joist was. Once I established which way the

joist runs progress is reasonably fast. Wth attics where you cannot hold onto the rafter when going down the middle I would move toward the side so I could hold on. In homes with Knob and Tube wiring some additional care must be taken to be sure of not being

tripped by wires running above the joists instead of through them. Hauling crawl boards around in a small car wasn’t practical so didn’t use that technique.

Rarely did I have to do attics with batts. In some ways easier, just lifted up a couple to find the joists the proceeded to either walk on the batts in the proper

places – they spring back better than loose fill. Or would pull up the batts and then replace them as I backed out.

Also learned (taught inspectors this) that my rechargeable flashlight needed to be charged every night. It died once when I was a long way from the access around

a couple of corners. Took 20 minutes sitting there waiting for my eyes to adjust to the dim light coming in the eave vents. Memorable crawl getting out.

Any of this help?

bill

From: iequality [mailto:iequality ]

On Behalf Of Norman Gauss

Sent: Wednesday, January 18, 2012 7:51 PM

To: iequality

Subject: RE: Re: Vapor barriers in attic floor insulation

Bill:

What is the technique for walking on joists that are hidden by insulation? Do you take two 1 x 12 boards that are about 4 ft long and

lay them across the joists end-to-end in the general direction toward which you are moving? If this is done, the insulation will be mashed down. Would this be bad for the insulation?

Norm Gauss

From:

iequality

[mailto:iequality ] On Behalf Of Holloway, Bill

Sent: Wednesday, January 18, 2012 12:45 PM

To: iequality

Subject: RE: Re: Vapor barriers in attic floor insulation

I humbly disagree with the advice about never covering joists. Blown insulation will cover all the joists, increasing their approximate

R-value from 3 or 4 to several times that depending on the type of insulation installed. Batts installed to cover the joists will have a similar effect. I am very sorry to hear your uncle was injured however I inspected attics daily for 6 years - all with

covered joists – and never fell through the ceiling ! or off the joists. In a mild climate such as here in California not covering the joists isn’t that big a deal. But in a cold climate like in Wisconsin the ceiling can develop ghosting due to the thin

strips of low R value created by uncovered joists.

Bill Holloway

_,___

[Guest guest]

The small lumber running perpendicular on top of the joist are called rat runs. Typically to small to support much weight between joists.

>  >> Hi Norm>>  >> When inspecting we didn’t have to walk on every joist of course.  We did have to reach a point/locations in an attic that allowed visual inspection of any area that contained heat producing devices – this was long before B vent was mandatory or IC recessed lites were produced – as well as establishing the depth/R value of the newly installed insulation.

>>  >> At first it was thought that the disturbed areas would have a significant effect on the total insulation value.  But when we did the math there wasn’t enough square foot of insulation disturbed to have a genuine and quantifiable effect to the heating or cooling bill.  Mathmatically there was a value but it is actually so small that other variables (t-stat settings, doors left open, etc.) were much more important.

>>  >> As to the technique for staying on the joists I would hold on to the rafter and sweep my foot over where I thought the joist was.  Once I established which way the joist runs progress is reasonably fast.  Wth attics where you cannot hold onto the rafter when going down the middle I would move toward the side so I could hold on.  In homes with Knob and Tube wiring some additional care must be taken to be sure of not being tripped by wires running above the joists instead of through them.  Hauling crawl boards around in a small car wasn’t practical so didn’t use that technique.

>>  >> Rarely did I have to do attics with batts.  In some ways easier, just lifted up a couple to find the joists the proceeded to either walk on the batts in the proper places – they spring back better than loose fill.  Or would pull up the batts and then replace them as I backed out. 

>>  >> Also learned (taught inspectors this) that my rechargeable flashlight needed to be charged every night.  It died once when I was a long way from the access around a couple of corners.  Took 20 minutes sitting there waiting for my eyes to adjust to the dim light coming in the eave vents.  Memorable crawl getting out.

>>  >> Any of this help?>>  >> bill>>  >> From: iequality [mailto:iequality ] On Behalf Of Norman Gauss

> Sent: Wednesday, January 18, 2012 7:51 PM> To: iequality > Subject: RE: Re: Vapor barriers in attic floor insulation>

>  >>  >> Bill:>>  >> What is the technique for walking on joists that are hidden by insulation?  Do you take two 1 x 12 boards that are about 4 ft long and lay them across the joists end-to-end in the general direction toward which you are moving?  If this is done, the insulation will be mashed down.  Would this be bad for the insulation?

>>  >> Norm Gauss>>  >> From: iequality [mailto:iequality ] On Behalf Of Holloway, Bill

> Sent: Wednesday, January 18, 2012 12:45 PM> To: iequality > Subject: RE: Re: Vapor barriers in attic floor insulation>

>  >>  >> I humbly disagree with the advice about never covering joists.  Blown insulation will cover all the joists, increasing their approximate R-value from 3 or 4 to several times that depending on the type of insulation installed.  Batts installed to cover the joists will have a similar effect.  I am very sorry to hear your uncle was injured however I inspected attics daily for 6 years - all with covered joists – and never fell through the ceiling ! or off the joists.  In a mild climate such as here in California not covering the joists isn’t that big a deal.  But in a cold climate like in Wisconsin the ceiling can develop ghosting due to the thin strips of low R value created by uncovered joists.

>>  >> Bill Holloway>> _,___>> -- C. HannerBuilding Diagnostics, LLC

1143 45th Avenue NESt sburg, FL 33703

[Guest guest]

Bill, you say you rarely have inspected attics that have batts. Is that because

blown in insulation is more common? I'm trying to decide betw fiberglass batts

or blown in cellulose now.

>

> Hi Norm

>

> When inspecting we didn't have to walk on every joist of course. We did have

to reach

[Guest guest]

Hi Bill: Good Advice! When I am creeping around attics, I am always afraid of losing my balance or my footing and accidentally rupturing the ceiling below. But if you manage to crawl into attics using the techniques you described, the next time I do that, I’ll try some of your methods. Thanks for the tips. Norm Gauss From: iequality [mailto:iequality ] On Behalf Of Holloway, BillSent: Friday, January 20, 2012 10:47 AMTo: 'iequality 'Subject: RE: Re: Vapor barriers in attic floor insulation Hi Norm When inspecting we didn’t have to walk on every joist of course. We did have to reach a point/locations in an attic that allowed visual inspection of any area that contained heat producing devices – this was long before B vent was mandatory or IC recessed lites were produced – as well as establishing the depth/R value of the newly installed insulation. At first it was thought that the disturbed areas would have a significant effect on the total insulation value. But when we did the math there wasn’t enough square foot of insulation disturbed to have a genuine and quantifiable effect to the heating or cooling bill. Mathmatically there was a value but it is actually so small that other variables (t-stat settings, doors left open, etc.) were much more important. As to the technique for staying on the joists I would hold on to the rafter and sweep my foot over where I thought the joist was. Once I established which way the joist runs progress is reasonably fast. Wth attics where you cannot hold onto the rafter when going down the middle I would move toward the side so I could hold on. In homes with Knob and Tube wiring some additional care must be taken to be sure of not being tripped by wires running above the joists instead of through them. Hauling crawl boards around in a small car wasn’t practical so didn’t use that technique. Rarely did I have to do attics with batts. In some ways easier, just lifted up a couple to find the joists the proceeded to either walk on the batts in the proper places – they spring back better than loose fill. Or would pull up the batts and then replace them as I backed out. Also learned (taught inspectors this) that my rechargeable flashlight needed to be charged every night. It died once when I was a long way from the access around a couple of corners. Took 20 minutes sitting there waiting for my eyes to adjust to the dim light coming in the eave vents. Memorable crawl getting out. Any of this help? bill From: iequality [mailto:iequality ] On Behalf Of Norman GaussSent: Wednesday, January 18, 2012 7:51 PMTo: iequality Subject: RE: Re: Vapor barriers in attic floor insulation Bill: What is the technique for walking on joists that are hidden by insulation? Do you take two 1 x 12 boards that are about 4 ft long and lay them across the joists end-to-end in the general direction toward which you are moving? If this is done, the insulation will be mashed down. Would this be bad for the insulation? Norm Gauss From: iequality [mailto:iequality ] On Behalf Of Holloway, BillSent: Wednesday, January 18, 2012 12:45 PMTo: iequality Subject: RE: Re: Vapor barriers in attic floor insulation I humbly disagree with the advice about never covering joists. Blown insulation will cover all the joists, increasing their approximate R-value from 3 or 4 to several times that depending on the type of insulation installed. Batts installed to cover the joists will have a similar effect. I am very sorry to hear your uncle was injured however I inspected attics daily for 6 years - all with covered joists – and never fell through the ceiling ! or off the joists. In a mild climate such as here in California not covering the joists isn’t that big a deal. But in a cold climate like in Wisconsin the ceiling can develop ghosting due to the thin strips of low R value created by uncovered joists. Bill Holloway_,___

[Guest guest]

Good luck Norm

From: iequality [mailto:iequality ]

On Behalf Of Norman Gauss

Sent: Saturday, January 21, 2012 11:49 AM

To: iequality

Subject: RE: Re: Vapor barriers in attic floor insulation

Hi Bill:

Good Advice! When I am creeping around attics, I am always afraid of losing my balance or my footing and accidentally rupturing the

ceiling below. But if you manage to crawl into attics using the techniques you described, the next time I do that, I’ll try some of your methods.

Thanks for the tips.

Norm Gauss

From:

iequality

[mailto:iequality ] On Behalf Of Holloway, Bill

Sent: Friday, January 20, 2012 10:47 AM

To: 'iequality '

Subject: RE: Re: Vapor barriers in attic floor insulation

Hi Norm

When inspecting we didn’t have to walk on every joist of course. We did have to reach a point/locations in an att! ic that allowed visual

inspection of any area that contained heat producing devices – this was long before B vent was mandatory or IC recessed lites were produced – as well as establishing the depth/R value of the newly installed insulation.

At first it was thought that the disturbed areas would have a significant effect on the total insulation value. But when we did the math

there wasn’t enough square foot of insulation disturbed to have a genuine and quantifiable effect to the heating or cooling bill. Mathmatically there was a value but it is actually so small that other variables (t-stat settings, doors left open, etc.) were

much more important.

As to the technique for staying on the joists I would hold on to the rafter and sweep my foot over where I thought the joist was. Once

I established which way the joist runs progress is reasonably fast. Wth attics where you cannot hold onto the rafter when going down the middle I would move toward the side so I could hold on. In homes with Knob and Tube wiring some additional care must

be taken to be sure of not being tripped by wires running above the joists instead of through them. Hauling crawl boards around in a small car wasn’t practical so didn’t use that technique.

Rarely did I have to do attics with batts. In some ways easier, just lifted up a couple to find the joists the proceeded to either walk

on the batts in the proper places – they spring back better than loose fill. ! ; Or woul! d pull up the batts and then replace them as I backed out.

Also learned (taught inspectors this) that my rechargeable flashlight needed to be charged every night. It died once when I was a long

way from the access around a couple of corners. Took 20 minutes sitting there waiting for my eyes to adjust to the dim light coming in the eave vents. Memorable crawl getting out.

Any of this help?

bill

From:

iequality

[mailto:iequality ] On Behalf Of Norman Gauss

Sent: Wednesday, January 18, 2012 7:51 PM

To: iequality

Subject: RE: Re: Vapor barriers in attic floor insulation

Bill:

What is the te! chnique f! or walking on joists that are hidden by insulation? Do you take two 1 x 12 boards that are about 4 ft long

and lay them across the joists end-to-end in the general direction toward which you are moving? If this is done, the insulation will be mashed down. Would this be bad for the insulation?

Norm Gauss

From:

iequality

[mailto:iequality ] On Behalf Of Holloway, Bill

Sent: Wednesday, January 18, 2012 12:45 PM

To: iequality

Subject: RE: Re: Vapor barriers in attic floor insulation

I humbly disagree with the advice about never covering joists. Blown insulation will cover all the joists, increasing their approximate

R-value from 3 or 4 to several times that depending on the type of insulation installed. Batts installed to cover the joists will have a similar effect. I am very sorry to hear your uncle was injured however I inspected attics daily for 6 years - all with

covered joists – and never fell through the ceiling ! or off the joists. In a mild climate such as here in California not covering the joists isn’t that big a deal. But in a cold climate li! ke in Wis! consin the ceiling can develop ghosting due to the thin

strips of low R value created by uncovered joists.

Bill Holloway

_,___

[Guest guest]

Sorry for the miscommunication. The majority of attics were insulated with blown fiberglass or cellulose. However DIY jobs that applied for a rebate were typically

batt installations. And customers typically laid batts between joists, not across because they were unaware of the performance improvement when going across the joists. More often than not they put any vapor retarder/barrier up because it looked neater.

And stuffed batts over recessed lights causing the thermal limiter to cycle. I just said their house was haunted. Eventually would explain why.

The attics with blown insulation were done by professionals. When rebate customers find out how much more batts cost to install – mostly labor – they opt for blown-in.

I have trained (in the past) our phone reps on the installed performance differences between batts and loose fill.

From: iequality [mailto:iequality ]

On Behalf Of barb b w

Sent: Friday, January 20, 2012 8:38 PM

To: iequality

Subject: Re: Vapor barriers in attic floor insulation

Bill, you say you rarely have inspected attics that have batts. Is that because blown in insulation is more common? I'm trying to decide betw fiberglass batts or blown in cellulose now.

>

> Hi Norm

>

> When inspecting we didn't have to walk on every joist of course. We did have to reach

[Guest guest]

Bill, but you can use 'unfaced' batts over recessed light, right?

>

> And stuffed batts over recessed lights causing the thermal limiter to cycle.

[Guest guest]

Depends on the recessed lights coding. IF it says IC rated (insulation contact) then bury it. BUT if there isn’t any sticker either on the inside where the lamp/bulb

goes or (much less common) a sticker on the upper attic side that says IC rated you cannot.

Here is what is going on: a non IC fixture/can light will over heat because the insulation blocks or nearly blocks the air holes that allow convection to cool the

fixture. Of course this means that the fixtures will allow a huge amount of conditioned air to leak into the attic. Taking with that air moisture from the house. Which may cause ice dams in the attic. But you bury the non IC cans and now the heat buildup

makes the thermal limiter trigger shutting of the power in that fixture. i.e. haunted house.

One remedy has been suggested: use cfls instead of the usual par or reflector lamps. Even then there may be enough trapped heat to effect either the fluorescent

lamps life and/or still trigger the thermal limiter.

With all of the above this is the typical suggestion for non IC cans/fixtures: leave 3” of clear space around the fixture. OR build a sheet rock or metal box that

contains a whole lot of air space. The increased surface area of this box will allow thermal dissipation but block unwanted air flow into the attic. The box needs to be around 24” high. A real chore to build. Might be easier to just swap out the cans for

IC + AT (air tight) rated cans.

Too much information?

bill

From: iequality [mailto:iequality ]

On Behalf Of barb b w

Sent: Monday, January 23, 2012 4:27 PM

To: iequality

Subject: Re: Vapor barriers in attic floor insulation

Bill, but you can use 'unfaced' batts over recessed light, right?

>

> And stuffed batts over recessed lights causing the thermal limiter to cycle.

[Guest guest]

Group,

I have followed the comments regarding the attic insulation and am surprised at the range of comments. There are multiple issues that must be considered prior to choosing the type and amount of insulation to be installed in an attic. One should always be cautious when trying to reinvent the mouse trap, especially for homeowners. Many times an effort to make any system more efficient can result in unanticipated results. It is hard enough for a professional to improve a system but it can be hazardous for a beginner. Experience is a hard teacher; it gives you the test first, and the answers later.

If you want to be successful then do what the successful people do. That is to say, ask a successful builder in your area how he would design an attic insulation system in this home. Do not rely on some salesmen to give you good information. Many times they are only repeating what they heard somebody else say. Rarely does a salesman understand the complexities of installing a complete system and they will fall back on the manufacturer’s installation instructions when things go sideways. The hard lesson is to read the manufacturer’s installation instructions prior to ordering the product, and once a product is selected then follow those recommendations to the letter. Otherwise the installer will be left liable when things go sideways.

Next understand that one reaches a point of diminishing returns when selecting a product. No product is perfect, and all products have some drawbacks. The key is to make an informed decision.

Shredded paper impregnated with poison and fire retardant vs. woven glass strands. The first thing I was taught in regards to mold remediation was not to introduce any biocides into a home. Cleaning a system was preferable to poisoning a system. So in this case we can choose between boric acid on paper and clean fiberglass. Cellulose insulation is soaked with boric acid as a fire retardant and as a biocide. What is generally unknown is that over time the boric acid leaches out of the paper resulting in a corresponding decrease in efficacy. I understand that after 30 years much of the fire retardant properties of the chemical treatment are lost. Cellulose will soak up water from a roof leak thus resulting in a large amount of water being collected in the attic which can, at worst, cause the ceiling to collapse and at a minimum, cause the cellulose to compact with a corresponding reduction in R-value. The cellulose will compact and take on the consistency of cardboard. Cellulose is a good product that has been successfully used in millions of homes but no product is perfect.

Fiberglass on the other hand is not treated with anything. It is glass strands that are non-reactive but can be crushed to produce tiny strands that have been compared to asbestos. While there is no definitive information regarding how fiberglass affects the lungs, I suggest installing a few batts without any mask or gloves. After a few minutes it will become clear that fiberglass should be treated with respect. Fiberglass will not soak up water like cellulose, but, it is little more than a giant horizontal filter. It will collect anything that moves through the system. Mold will not grow in the fiberglass, but mold will grow on the dust that collects inside the glass matrix, just add water vapor and a growth will occur that is indistinguishable from a growth inside a wet cellulose area.

The location of the vapor barrier is very important. It changes from geographical location, humidity and temperature. For temperate climates “generally†the vapor barrier, I mean vapor retarder, or water plane or whatever you choose to call it, has the paper to the warm side. And many times, it is not necessary to even be installed. Vapor retarders are is designed to keep liquid water out of the system, and let the water vapor move through the system. The idea is to provide a way for the wet areas to air dry. In areas that vary a great deal in temperature it is important that the vapor retarder be placed in the proper location. Sometimes it is against the ceiling, sometimes it at the top but from what I can gather in this case, it may be somewhere about 1/3 of the way up from the ceiling. The location is a technical determination based on the number of degree days in that specific location. This determination is complicated by the sealing of the ceiling system in an effort to increase energy efficiency. I recommend that you get some professional guidance in the regard. In no case should multiple vapor retarders be installed and I would be cautious when combining different types of insulation, as that may affect they overall perms of the system. That is to say the speed at which the water vapor moves through the insulation.

In no case should there be any air spaces between the top of the ceiling and the bottom of the insulation. I do not recommend batts in a retrofit upgrade.

Another consideration for either product is the depth of the insulation after it is installed. R-38 is not uncommon, it will come up over you knee and will cover everything in the attic. Knob and tube wiring is not rated to be buried in insulation. Knob and tube wiring requires open air for temperature control, if it is buried and there is an insurance claim, the insurance company will use the improper installation of the insulation as a reason to disallow the insurance. This is a no-no.

Another issue is that some devices cannot be buried in insulation. Recessed light cans must be rated in order to be buried in insulation. Some are rated to be buried and some are not. There should be a label inside the recessed light can that will state whether or not it can be buried in insulation. There have been multiple fires attributed to inappropriate installation of recessed light fixtures. Again, the insurance company will use improper installation as a reason to disallow insurance benefits.

Lastly, exhaust vents, and zero clearance fireplace systems are not rated to touch insulation. Insulation will interfere with the dispersion of heat from the combustion by products and can cause premature condensation inside the vent. Shields must be installed to keep the insulation away from these types of systems.

And lastly, lastly, consider how you will service the attic systems and the HVAC duct system after the attic is filled with insulation. R-38 will effectively prohibit access to the attic systems. It will take great effort and time to move through this stuff. And it will take a physically fit person to do it. There are very specific codes that control attic access but generally qualified specialist will not go into potentially hazardous locations, at least without a hold harmless agreement. The attic will be for all practical purposes, non accessible. So the duct systems etc. will become a lifetime system that will be very difficult and costly to maintain.

I hope this helps,

Brad Deal CIEC

RE: Re: Vapor barriers in attic floor insulation

I humbly disagree with the advice about never covering joists. Blown insulation will cover all the joists, increasing their approximate R-value from 3 or 4 to several times that depending on the type of insulation installed. Batts installed to cover the joists will have a similar effect. I am very sorry to hear your uncle was injured however I inspected attics daily for 6 years - all with covered joists – and never fell through the ceiling ! or off the joists. In a mild climate such as here in California not covering the joists isn’t that big a deal. But in a cold climate li! ke in Wis! consin the ceiling can develop ghosting due to the thin strips of low R value created by uncovered joists.

Bill Holloway

_,___