I live in western NY and the weather here for the last week or so has been
around low 30"s, I was in the attic the other day and the nails coming
through the roof are dripping water....I have a full ridge vent, full soffit
on the west side of the house(and they aren't blocked by any insulation),
and gable vents. It is definately cold in the attic and there is about R25
on floor w/ barrier down towards living space, the roof was replaced about
10 yrs ago....what is causing this and should I be concerned?

Gntry wrote:

I live in western NY and the weather here for the last week or so has been
around low 30"s, I was in the attic the other day and the nails coming
through the roof are dripping water....I have a full ridge vent, full soffit
on the west side of the house(and they aren't blocked by any insulation),
and gable vents. It is definately cold in the attic and there is about R25
on floor w/ barrier down towards living space, the roof was replaced about
10 yrs ago....what is causing this and should I be concerned?



Might not be your cause, but I had a similar situation
that defied explanation. It was so bad that at times
it was practically raining in the attic!

Turns out that that the gas furnace was the culprit.
It vented into a brick chimney which had a proper clay flue liner.
The chimney was in the center of the attic space.

The original monster furnace had been replaced with a much
smaller unit and, I surmise, flue gas temps inside the
chimney were now low enough to cause more condensation.
This moisture could actually be seen weeping out of the
brick mortar joints.

A metallic liner for the flue cured the problem.

Jim

"Gntry" wrote in message
news:HQwzf.2167$pq5.1585@trndny02...

I live in western NY and the weather here for the last week or so has been
around low 30"s, I was in the attic the other day and the nails coming
through the roof are dripping water....I have a full ridge vent, full
soffit
on the west side of the house(and they aren't blocked by any insulation),
and gable vents. It is definately cold in the attic and there is about R25
on floor w/ barrier down towards living space, the roof was replaced about
10 yrs ago....what is causing this and should I be concerned?

First, find out whether this is moisture traveling along
the nails from the roof top surface to the under side, or condensing
from the interior attic air onto the surface of the nails (cooled
by their heads through the sheathing.)

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

Just guessing but....
I suspect the cause is why a cold glass of beer sweats on a hot summer
day. The nail is much colder than the warmer attic air. When dewpoint gets
close to temperature
you get visible water vapor. Try a small fan to get the air moving. Again,
only a guess.

"Gntry" wrote in message
news:HQwzf.2167$pq5.1585@trndny02...
I live in western NY and the weather here for the last week or so has been
around low 30"s, I was in the attic the other day and the nails coming
through the roof are dripping water....I have a full ridge vent, full
soffit on the west side of the house(and they aren't blocked by any
insulation), and gable vents. It is definately cold in the attic and there
is about R25 on floor w/ barrier down towards living space, the roof was
replaced about 10 yrs ago....what is causing this and should I be
concerned?

Haven't experience that, but guessing it may be simple condensation. The
nail conducts the cold from the base of the shingles, and if you have a
warmish, humid attic, it will condense, just like on the inside of a single
glazed window on a cold day. Perhaps your attic needs more ventilation to
lower the humidity.

"Gntry" wrote in message
news:HQwzf.2167$pq5.1585@trndny02...
I live in western NY and the weather here for the last week or so has been
around low 30"s, I was in the attic the other day and the nails coming
through the roof are dripping water....I have a full ridge vent, full
soffit on the west side of the house(and they aren't blocked by any
insulation), and gable vents. It is definately cold in the attic and there
is about R25 on floor w/ barrier down towards living space, the roof was
replaced about 10 yrs ago....what is causing this and should I be
concerned?

might be condensation. the nails would be at somewhat lower temp
than the surrounding materials.
is attic vented?
any exhaust from the living space vented into the attic instead of outdoors?

bill


"Gntry" wrote in message
news:HQwzf.2167$pq5.1585@trndny02...
I live in western NY and the weather here for the last week or so has been
around low 30"s, I was in the attic the other day and the nails coming
through the roof are dripping water....I have a full ridge vent, full
soffit on the west side of the house(and they aren't blocked by any
insulation), and gable vents. It is definately cold in the attic and there
is about R25 on floor w/ barrier down towards living space, the roof was
replaced about 10 yrs ago....what is causing this and should I be
concerned?

bill allemann wrote:

might be condensation. the nails would be at somewhat lower temp
than the surrounding materials.
is attic vented?

I think he covered that!

any exhaust from the living space vented into the attic instead of
outdoors?

bill


"Gntry" wrote in message
news:HQwzf.2167$pq5.1585@trndny02...

I live in western NY and the weather here for the last week or so has
been around low 30"s, I was in the attic the other day and the nails
coming through the roof are dripping water....I have a full ridge
vent, full soffit on the west side of the house(and they aren't
blocked by any insulation), and gable vents. It is definately cold in
the attic and there is about R25 on floor w/ barrier down towards
living space, the roof was replaced about 10 yrs ago....what is
causing this and should I be concerned?




--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

"bill allemann" wrote in message
om...
might be condensation. the nails would be at somewhat lower temp
than the surrounding materials.
is attic vented?
any exhaust from the living space vented into the attic instead of
outdoors?

Maybe a bathroom fan whose duct is leaking moist air into the attic?

Gntry wrote:

I live in western NY and the weather here for the last week or so has been
around low 30"s, I was in the attic the other day and the nails coming
through the roof are dripping water....I have a full ridge vent, full soffit
on the west side of the house(and they aren't blocked by any insulation),
and gable vents. It is definately cold in the attic and there is about R25
on floor w/ barrier down towards living space, the roof was replaced about
10 yrs ago....what is causing this and should I be concerned?


I think you need to quantify "cold in the attic." Put a thermometer
up there. It could be pretty cold and still be warm enough for the
nails to be a lot colder. Everything's relative when you're talking
about relative humidity. :-)

In fact, you could probably also directly measure the humidity up there
with a cheap hygrometer (although I don't know how good they are at cold
temps).

Is your furnace in the attic, by any chance?

Could there be gaps in that moisture barrier, perhaps around light
fixtures, vent pipes, etc., that are leaking enough conditioned air
to carry the moisture you're seeing?

Can you discern whether some are dripping more than others? The worst
offenders might be nearest the source of moisture.

I would be concerned, particularly because of the possibility of mold
developing.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

Roger that, Roger, on the moisture condensing. Under prev. owner, my
house had a variety of air leaks from heated space into attic. Roofing
nails, having their large heads very near the Great Outdoors and having
much greater thermal conductivity than plywood deck, served as main
points of condensation. Such that you could see pattern of staining
around their protruding shanks in summer. Slowly fading now. And ...
energy consumption waaaaay down.

OP might look for entry point(s) of relatively high absolute humidity
air from below. They sure are there, and with chimney-effect it doesn't
take a lot of flow-area.

HTH,
J

"Gntry" wrote in message news:HQwzf.2167$pq5.1585@trndny02...
I live in western NY and the weather here for the last week or so has been
around low 30"s, I was in the attic the other day and the nails coming
through the roof are dripping water....I have a full ridge vent, full soffit
on the west side of the house(and they aren't blocked by any insulation),
and gable vents. It is definately cold in the attic and there is about R25
on floor w/ barrier down towards living space, the roof was replaced about
10 yrs ago....what is causing this and should I be concerned?

Is it possible that the problem is caused by having the attic door opened?
If you go up, is the moisture there when you first get there, or only after
its been opened for awhile?

Bob