Vapor barriers in attic floor insulation

[Guest guest]

Barb

You said that you had someone seal the attic floor, so that it should be airtight. If the ceiling light pots were not changed to the sealed type, you have massive openings into the attic, with all of the attendant problems.

Besides, ceiling lights, until we get LED versions, are an abomination from both an energy and a health point of view.

Jim H. White SSC

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]

I misspoke, I have penetration for hanging lights but they are not recessed. The electrical work has been reworked in areas and been inspected twice in preparation for air sealing demands. Once by them and a second time by someone I hired independently since sometimes people who inspect are friends of the workman. The air sealing was just at the tops a walls and around penetrations like you recommended way back. I paid almost a thousand dollars a few years ago to have attic insulation sucked out and then more to be cleaned out by Servpro...no mold found but plenty of soot. Now I did the air sealing and they are coming today to do blower door test and retest air tightness. The house smells fresher with air not coming through walls anymore, at least so far. Have to see what summer brings. Barb

You said that you had someone seal the attic floor, so that it should be airtight. If the ceiling light pots were not changed to the sealed type, you have massive openings into the attic, with all of the attendant problems.

Besides, ceiling lights, until we get LED versions, are an abomination from both an energy and a health point of view.

Jim H. White SSC

[Guest guest]

Back in 1985 I received a free energy grant from my electric utility to add

insulation to my attic. The power company representative recommended blown in

cellulose insulation. At the time I was only formaldehyde intolerant (and maybe

food preservatives at that time). He told me that boric acid is " non-toxic. " It

was not non-toxic for me. I rented my house out for a year hoping that the

cellulose dust would become inactive. It did not. When I came back it was still

triggering my bronchitis. I eventually had a special sleeping room built and

lived in there for most of the 19 years I owned the home. I did try to remove

the insulation (all of it). The attic was vacuumed about three times(after major

parts were donated to be hauled away to a friend's home who was insulating).

During the process of my exposure I developed intolerance to the bromates in

electrical equipment.

What I have learned from my experience over these years is that my pathways for

detoxification of biocides is not functioning within normal ranges. My primary

environmental triggers which trigger bronchitis (environmentally induced) are

all biocides (formaldehyde, pesticides, herbicides, boric acid and related

bromates, food preservatives, and micotoxins from molds). I do not suspect that

everyone will have the same level of intolerance to the boric acid in the

cellulose insulation I did, but never forget that it is a POISON. It may not be

a poison that kills a human easily, but have no doubt that in sufficient levels

it will impact the IAQ of those exposed to it. Here is a point you can bank: if

one has an intolerance to any biocides, then avoidance of all other biocides is

a must. Avoidance to all biocides becomes an essential criteria for tolerable

IAQ for me. Others mileage may vary.

Don Paladin WSMCSN owner

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> 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

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> 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.

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> Bill Holloway

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[Guest guest]

sunergos, do you have fiberglass in your home or do you have it foamed?

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> Back in 1985 I received a free energy grant from my electric utility to add

insulation to my attic. The power company representative recommended blown in

cellulose insulation.

[Guest guest]

Hi Barb,

I have not taken on the attic insulation in my home yet. I have 50 year old

kraft faced fiberglass and rock wool. I also need to change the heating system

(have very expensive old base board electric heat). Someone has recommended a

mini-split and hvac for whole house. Lots of things to do. I think removing the

old insulation and then sealing the attic may be my first step (like you did). A

number of members in my MCS network have used Mansville insulation without

a problem (or one they were aware of). Since formaldehyde and most biocides are

a big problem for me, I a leaning to re-insulating with that later. In the house

in which I had cellulose blown in the attic, I actually had zero attic

insulation for a good part of 19 years that I owned it. I realize that it is a

costly way to live, but the choices were just not there for me.

Have you heard about a new product from France and made in Taiwan called SKYTECH

& NEST? I picked up a sample at the environmental home store in Seattle. It is

made by WINCO International Corp. Their website is at www.winco-tech.com . The r

factor is not so great (R13.7 and R12.5) but I was thinking it might be a good

vapor barrier too (one is perforated). I received a quote of about $500 for just

200 sq ft of it. That is one roll. Actually it was less than $500 but I cannot

remember now the exact amount. They also have an ECO_BATT (fiberglass) but I

have not tried a sample. Here is their site:

http://www.greendepot.com/greendepot/ . BE WARE! They carry many so called

" green " products that contain chemicals that may not be biocompatible with

someone with severe intolerances.

Be well,

Don Paladin WSMCSN owner

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> > Back in 1985 I received a free energy grant from my electric utility to add

insulation to my attic. The power company representative recommended blown in

cellulose insulation.

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