I have been experiencing some moisture in my attic this year and would
like to get some advice on how to solve the problem.


What's in my attic:
- The attic has a continuos ridge vent with continuos soffet vent along

both eaves. The vents seem to be working and there is no insulation
blocking the soffet vents.
- The attic floor is well insulated with R30 insulation w/ an attach
vapor barrier facing the attic floor.
- My drop-down attic stairs has a battic door w/ insulation so there
shouldn't be any heat leak though the opening.
- The bathroom fan is vented through the soffet vent and no air is
escaping in the attic
- There is a gas hot air furnace in the attic which had some leaking
duct work. The leaks have been fixed and some additional insulation has

be added to the ducts.


I thought by fixing the leaks in the ducts, my problem would be solved,

but the North side of the roof still has some moisture. It is a two
story house located in eastern MA. The house does not have a lot of
humidity (usually around 30 - 45%). and the attic is definitely cold.
It has been a rather damp winter in the Northeast, maybe that has
something to do with the problem.


The only options that I can think of a


1. Add an additional vent where the furnace is located just in case
there is some small heat leaks that I missed. (If I do this, I'm
worried that this would affect the airflow for the ridge vent)
2. Install an Attic Fan w/ an Adjustable Thermostat and Humidistat with

the idea that the humidistat would detect moisture build and vent it
out. Any suggestions on what the humidistat should be set at (I'm
thinking 45 - 55%)


Please let me know if anyone has any suggestions on something else to
check in the attic, or what you think of my options and which one would

work the best.


thanks in advance

"pln" wrote in message
oups.com...
I have been experiencing some moisture in my attic this year and would
like to get some advice on how to solve the problem.

When you say "experiencing some moisture", what exactly is the problem? You
will always have some level of moisture. Sometimes you will even see small
bits of ice forming on the nails that come thru the plywood sheating used
for the shingles. This is OK. Please describe what the symptoms are.
Everything you described sounds right for venting and insulation except that
the vapor barrier is supposed to be on the warm side of the insulation which
means between the drywall and the joists of the ceiling of the second floor.
The real culprit is definitely the furnace. Some gas furnaces have a
condensate that needs to be drained to the outside, usually into a gutter if
it's in the attic.

-al sung
Rapid Realm Technology, Inc.
Hopkinton, MA

Thanks for the reply Al.

The vapor barrier is facing the second floor ceiling so that is ok.

The symptons are the nails do have fost on them when it's gets really
cold and there is some frost on the plywood sheating. The north side of
the roof does have some mositure right by the soffet vents (the
affected mositure area is a goes up 2 - 3 feet into the attic).

I had the furance checked out and everything is in working order. One
thing that I did this summer was to seal the area around the base of
the steel stack for the chimney. It did have a mesh area around it that
was used for venting but rain was leaking into the attic. The stack
does have another vent further up the stack but it is much smaller. Do
you think this could be causing the problem?

thanks,
paul

"pln" wrote in message
oups.com...

Thanks for the reply Al.

The vapor barrier is facing the second floor ceiling so that is ok.

The symptons are the nails do have fost on them when it's gets really
cold and there is some frost on the plywood sheating. The north side of
the roof does have some mositure right by the soffet vents (the
affected mositure area is a goes up 2 - 3 feet into the attic).

This sounds pretty normal for an attic in New England. Some moisture will
inevitably leak into the attic space or it can just be normal ambient
moisture from the outdoors. When it's really cold out, it will condense on
the nearest cold surface before it has a chance to get vented out. Consider
when your car gets frosted up on the outside of the windshield even when
there is no precipitation. It's just moisture in the air condensing on a
cold surface and there's unlimited venting around your car. That same
moisture will frost up the nail heads and the plywood sheathing even in a
well vented attic.

-al sung
Rapid Realm Technology, Inc.
Hopkinton, MA

Thanks Al, it sounds like everything is working as well as it can.

I may replace the collar around the stack pipe that I sealed up to get
some more ventilation in the attic

Regards
Paul