Attic insulation question?

Question

For an attic that is not being used as living space. Which side of the fiberglass insulation should face down? In other words, should I see the paper backing or the fiberglass after I put it down.

Answer 1

The purpose of the insulation is to provide dead air space between the room and the exposed elements. The more dead air space, the higher the R value. Generally, kraft faced insulation is installed paper side up or visible.

Answer 2

Paper facing you is standard. Certainly that only applies to roll type. More common lately, even in a non living space is blown in.

What R value are you trying to achieve? How well insulated is the rest of the house? Overkill in an attic can't hurt either.

Just my two "sense"

Answer 3

you should see the fiberglass after you put it down.

Answer 4

NO!YOU SHOULD SEE THE PAPER SIDE.IT ACTS AS A VAPOR BARRIER.

Answer 5

when vapor leaves your house it will freeze in the winter. If the vapor leaves through your insulation the water will freeze and accumulate in the insulation and reduce its r value. For this reason, it is best to put an additional vapor barrier such as plastic sheeting down under attic insulation, and have the backing face down. thus the vapor is forced to leave through other means than through your insulation. additionally make sure you have proper venting of bathrooms to minimize the amount of vapor trying to exit through your ceilings.

If you may want to use the space for living in the future, I would use solid insulation that is not effected by moisture and put it just under the roof, otherwise just above the ceiling is preferred.

if you live in a place where it never freezes this may not be as much of a concern

If you are having blown in insulation installed (which is not what was in the question) then no vapor barrier will be used

Answer 6

when you are installing insulation you put the fiber into the wall and have the paper facing you. you want the insulation to work as a shield to cool the house and not the opposite way. Also, when doing this job make sure you ware a mask and long selves and cover yourself cuz the insulation will get all over you and itch. After, you finish put the clothes to wash separately.

Answer 7

Attic insulation should be blown in   ..If not,  attic insulation does not need nor should it have paper on one side

Answer 8

while i am not sure exactly how it is done, but if this helps our wall spaces that were insulated (not by us) like in the basement and in back of a closet where a hole was cut  in the wall and stuffed with insulation they showed the fiberglass side. most of the cold air would come in so i would think that if u put the paper backing first it would block any small holes. in the walls and ceilings u would want to put the paper facing outward. on a ceiling also u use plastic and walls u use paper. the plastic helps to resist condensation since it rises and may also help to resist any possible leakage that u may have in the roof.

Answer 9

Holy cow....

You mentioned the attic already HAS insulation.

Is the paper for the original insulation on the same side as the ceilign below? In other words if you were standing looking up at the ceiling and had x-ray vision would you see the paper?

If so thenthe original insulation is installed correctly.

Now you want to add more. Good idea.

Go to the stroe and simply buy "unfaced" (no paper) insulation.

Lay it over the top of the existing insulation.

GLoves, and a MASK especially the mask are important.

Regards,

Eric

Answer 10

You have received a plethora of useless and confusing information here.  

You are asking about using faced insulation in the attic.  The important thing is to understand the purpose of the kraft or foil facing on the insulation.  

The sole purpose of the facing is to serve as a vapor barrier, to prevent moisture from passing through.  A vapor barrier is used to prevent moisture in your home from passing into the walls (and thus the insulation) of your home.  Moisture captured in the insulation reduces the insulation value and allows warm air to escape, thus negating the purpose of insulation.  Think of it like this, are you warmer in dry clothes or wet clothes? Since wall cavities are not designed to allow moisture to pass through, moisture trapped in the walls lead to damage, often dry rot and mold.  The vapor barrier prevents moisture from entering the wall cavity, therefore, the rule is that THE VAPOR BARRIER GOES TO THE WARM SIDE OF THE WALL, THE HEATED INTERIOR SPACE.  

But moisture trapped in the home is not good either, and you must have a way to evacuate it.  The two most concentrated areas are the bathroom and kitchen areas, followed closely by the laundry room.  The best prevention of moisture buildup in those areas is mechanical ventilation, but extended use also evacuates the heat (or cooling) in the home.  So we must also have a passive method to evacuate the moisture.  That is to allow the moisture to safely pass through the insulation into the vented attic space.  The ceiling consists of drywall on the warm side and insulation exposed directly to the attic space.  Air moving through the attic evacuates the moisture from the insulation to the outside and keeps the insulation dry.  Therefore, a moisture barrier in the attic is an improper installation and should not be used.  Think of it this way, many attics are insulated with blown-in insulation, and by design have no vapor barrier.  You can go into your attic and carefully lift the insulation.  You should see no facing on the insulation, and no plastic across the ceiling joists, just the exposed back of the dyywall.  

So the proper way to insulate (or re-insulate) an attic is to avoid a vapor barrier.  You can use blown-in insulation, or UNFACED insulation batts (applied perpendicular to the ceiling joists).  If you have faced batts that you must use, make several diagonal slashes at random across the face, and apply the kraft or foil face DOWN to allow the moisture through the vapor barrier.  

Here is a link to verify this information: