I noticed paint bubbling in my kitchen ceiling. I went into the attic
andfound alotof water underneath the tar paper vapour barrier as well
as on top of the tar paper, which must have been soaked trough. The
insulation is opnlywet where it meets the vapourbarrier. What the
hell is going on here. I've about 50 sq feet of dammage plaster
Do you have a ceiling exhaust fan ? If so , is it venting into your
attic or out the roof or eave vent ? If there is a fan exhausting or
even leaking into the attic , your pumping warm humid air into a cold
attic causing moisture . That is a no no ! If this isn't the problem ,
you either have a roof leak ( possibly ice damming ) or your house is
so tight you have a moisture problem . Humidifiers can cause this if
the house can't breathe . Just a couple sugestions to start
investigating . Hope it helps .
On Mar 16, 5:31 pm, email@example.com wrote:
I think I hit the wrong post button. Anyway, what I was saying, is
that the water is under the barrier against the celing material. I
did have a lot of ice on the roof, so much that it had forced its way
under the shingles and made the wood panels wet. This however dried
up within two days of me clearing the ice. I'm so confused because
the insulation is not wet. It's only wet way down deep where it meets
the vapour barrier. I do have a vented microwave that goes out the
roof through the attic, but this duct is insualted.
Fiberglass insulation? If so, it seems it would be wet only on the
bottom of the layer, as water
drains quickly and the top of it would not feel wet. Sounds like you
had an ice dam that backed
up and dripped on the insulation. It would flow across the vapor barrier
and collect, seeping slowly
through seams and/or nail holes. Water could collect in the bottom of
the space for some time
before leaking through the barrier, and that would allow the upper
portion of the insulation to feel
dry. That is only my logic :o)
I had a similar backup, just from gutters being full of leaves
(Florida, no ice) and got a smaller wet spot on a ceiling.
Do you have a bathroom exhaust fan - is it anywhere near the area ?
Are you sure the the piping from a fan ( especially if it's flexible )
is not leaking or not connected at the fan properly , thus allowing
humid air to escape ? There could be a spot in the pipng that moisture
is puddling at and leaking ? Was the snow or ice sitting above where
it vents out the roof ? If so , this could cause the warm air to melt
any ice or snow above and arround the roof vent , and it is melting
back down in thru the vent into the house . Is your house humidified ?
My understanding is that tar paper is a moisture barrier, not a vapor barrier -
that is, it allows vapor to pass through it. So, the vapor in your house passes
through it, then condenses in the insulation. It is possible a vapor barrier
paint could help.
Otherwise, install a proper vapor barrier in the attic under the insulation, or
install insulation with a built in vapor barrier.
Theres no venting from anything in the attic. The exhaust from thr
Microwave is 6 inch galvanized insulated pipe. It's blowing into a
lot of snow and has melted a large patch. The damage area in the
attic is about 50 sq ft. It is also above the portion of the kitchen
where all the cooking is done. i.e the stove is there, kettles, etc.
I do have a humidified house that is automatically controlled. At -10
C I think I'm around 29% relatice humidity. Could this be as was
mentioned, moisture going through the tar paper? Would 6 mil plastic
be better? Does that much moisture actually travel through the
celing? Right now I'v removed the damaged insulation in the hopes of
the celing drying out.
I'm no expert here . I have experienced some problems like you . No
matter what , whether you have a leak , or a moisture problem ,
replacing the barrier is half the battle . You still need to address
where the moisture is coming from , and how you are going to remove it
from your house . There seems to be a lot to cause that damage and it
needs to be removed from your house .
On Mar 16, 6:18 pm, firstname.lastname@example.org wrote:
Thanks for all fo your input everyone. As I said earlier. There was
quit a lot of leakage through the shingles over the whole damaged
area. The wood wood roof panels were wet to the touch. If thats true
what was said about fibreglass insulation allowing water to penetrate
quickly, then all this may just make sense. I'm assuming the tar
paper will let the water through it eventually? I have loose fill
blown in over bats by the way
I know next to nothing about insulation (I know fiberglass when I see it
:o), but the idea of
water draining quickly through the insulation so that the top of the
layer feels dry would not
seem to apply to cellulose.........the vapor barrier is between the
ceiling and the insulation,
right? It doesn't make sense, to me, that moisture from the indoor
space would move through
the ceiling, through the v.b., and collect above the v.b.
Got soffits or open rafters? Any plumbing in the attic space? If the
insulation is real wet, and
the plaster is wet, I would be concerned about the added weight causing
it to fall down. Real
plaster? Any sags?
Another thought is whether wind driven rain might have added water in
addition to whatever
came from the ice dam. Had bad wind storms? Got plenty of ventillation
and ridge vents? It
would be worthwhile to have a couple of roofers look at it, get bids for
any needed repairs
On Mar 16, 7:47 pm, email@example.com wrote:
We have had real bad winds this winter blowing right at the back of
the house. Where my problem is. But the problem is still somewhat
localized and the penetration is at least 10 feet away from the
soffits. The vapour barrier is between the ceiling and the
insulation. Will the tar paper let water penetrate through it, so
that it comes in contact with the giprock? If so then this is most
likely the cause. As dfar as solving the ice damn, im re-doing the
eaves this summer and adding the heated wire for the winter. I
shoveled some of the snow off the roof gently I may add. The damaged
are is under the part of the roof that would be 1/3 of the way from
the wall (side split) and 10 feet from the eaves so past the ice
guard. About mid way between the eaves and the peak. The rood is 5
years old, well shingles I mean. And black paper was applied to the
whole roof and the bottom 3 feet have the rubber ice guard as well as
a drip edge.
This has to be water from above. I just read an artical saying that
if you have at least two coats of oil based paint on the cealing, then
that alone is a vapour barrier, and one in the attic is not really
required. This was a question from an individual who wanted to
insulate an 80 year old home's attic, and was told to not even bother
if that plaster celaing is coated in oil. For that matter I can
guarantee my 42 year old cealing is covered in oil as well. theres no
way the water below my tar paper came up from the kitchen, it would
have to be from above. oes this make sense to any of you?
I agree - I cannot imagine the amount of moisture you describe moving
through a coat of paint.
Acryllic paint allegedly breathes a tad more than oil, but it is still
waterproofing. Someone said
something about a microwave vent melting snow - OP or someone else?
Vent penetration or
flashing can leak, so those should be looked at as possibilities. My
daughter recently had a
leak in an area of repeat problems from a bad remodel.ing feature. She
is happy to have a roof
over her head and if it leaks a little bit, well, life could be a whole
lot worse :o) We talked about
roof leaks and got to the matter of ice dams. She called me back the
next day to tell me what
happened when she cleaned her gutters :o)
If I remember the formula, there should be one square foot of ridge vent
for each 300 square feet
of attic FLOOR space. Sounds like your problem might be too high, but I
don't know how high
ice damming can leak. I've seen small leaks follow a rafter or brace
and fall far from where the
water enters. Good luck!
that would work.
It doesn't take much moisture getting through to add up over time, as very
little evaporates in the cold temps.
Obviously, leakage has to be dealt with separately.
Does that much moisture actually travel through the
The best way to explain it is that you have moist - warm - rising
air , penetrating the ceiling . It reaches the colder attic and is
condensating under the barrier . It may actually frost up under there
until it warms up . When it thaws , then the problem starts . Just
like a glass off ice water . Cold water inside the glass , warm on the
outside . Then the glass sweats and you have moisture on the outside .
More so if it is humid out . If this indeed is your problem , the
humidity in your kitchen as you cook could cause these problems . If
so , you need to rid your house of extra humidity possibly caused by
cooking or showers .
But then there is the damming problem ! The heat loss from your
house helps cause this . Just make sure you find the true culprit .
Jetmech - Just a heads up . Removing snow from your roof is ok .
Removing the ice is another question . You may actually damage your
roof and shingles more if you physically try to remove it . You did
claim you removed it correct ? Frozen shingles are hard and brittle .
They crack easily . I'm not sure if you are saying you did this . But
doing so is asking for more problems . Good Luck !!!
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