I have a bathroom with no windows. It has a ceiling fan which will suck the
moisture from a shower into the attic.

Question.........is dumping the bathroom moisture into the center of the
attic harmful to the attic insulation?

Thanks,
rac

"racarson" writes:
Question.........is dumping the bathroom moisture into the center of the
attic harmful to the attic insulation?

Exhausting the bathroom into the attic is an extremely bad
idea. See this previous thread in this newsgroup:

http://groups.google.com/group/misc....ba7d65515a914e

"racarson" wrote:

I have a bathroom with no windows. It has a ceiling fan which will suck the
moisture from a shower into the attic.

Question.........is dumping the bathroom moisture into the center of the
attic harmful to the attic insulation?

Not if the attic is vented properly and the insulation is fiberglass and
installed properly. Although current code in most locations requires direct vent
to outdoors, there are lots of older housing that vent to the attic. If you have
untreated cellulose (ie shredded paper) or other unusual insulation material,
there might be an issue.

"Clark W. Griswold, Jr." writes:
Question.........is dumping the bathroom moisture into the center of the
attic harmful to the attic insulation?
Not if the attic is vented properly

I disagree. Even a properly vented attic can get humid enough
to foster mold growth if a bathroom with a shower is vented
into it rather than vented straight to the outside. There's a
reason why current code in most locations requires venting
directly to the outside. Why take the chance? Spend a few
hundred bucks to run a vent from the fan to the outside; it's
well worth the peace of mind.

racarson wrote:
I have a bathroom with no windows. It has a ceiling fan which will suck the
moisture from a shower into the attic.

Question.........is dumping the bathroom moisture into the center of the
attic harmful to the attic insulation?

Thanks,
rac



One word: MOLD

See:

http://www.findingthemold.com/photos.html
And
http://www.hardyservices.com/remediation_2.dws
And
http://www.allergybuyersclub.com/faqs/moldy-attic.shtml
And
http://www.ronhungarter.com/ventilation_repairs.html

Jim

(Jonathan Kamens) wrote:

Not if the attic is vented properly

I disagree. Even a properly vented attic can get humid enough
to foster mold growth if a bathroom with a shower is vented
into it rather than vented straight to the outside. There's a
reason why current code in most locations requires venting
directly to the outside. Why take the chance? Spend a few
hundred bucks to run a vent from the fan to the outside; it's
well worth the peace of mind.

Oh - I don't recommend the practice, but you're going to have to be taking an
awful lot of long hot showers on a frequent & regular basis to push that much
humidity into the attic - especially when compared with the amount that might be
there from living Seattle or a similar damp enviro. If the OP lives in Phoenix
or anywhere else in the southwest, it's unlikely to be an immediate problem.

That said - if the builder took a shortcut there, there's probably a lot of
other things that need attention. The attic venting is probably not sufficient
either.

"racarson" writes:

I have a bathroom with no windows. It has a ceiling fan which will suck the
moisture from a shower into the attic.

Question.........is dumping the bathroom moisture into the center of the
attic harmful to the attic insulation?

My current home had two vents that dumped into the attic plenum, and
the inspector flagged them in a heartbeat. Since then I've read lots
of confirmation of his doing this, it is considered very bad to do so,
and any home inspector is likely to flag it when you go to sell,
regardless of the ventilation situation in your attic.

The bathroom fan should be vented to a roof cap.

Best Regards,
--
Todd H.
http://www.toddh.net/

"Oh - I don't recommend the practice, but you're going to have to be
taking an
awful lot of long hot showers on a frequent & regular basis to push
that much
humidity into the attic - especially when compared with the amount that
might be
there from living Seattle or a similar damp enviro. If the OP lives in
Phoenix
or anywhere else in the southwest, it's unlikely to be an immediate
problem. "

Depending on the environment, it may not take all that much to cause
problems. I've seen threads here of people with mold and rot problems
caused by attic venting of a bath fan. I don't know how many showers
any of them took, but this is just wrong and should never be done,
period. For one thing, most attics don't get visited very often. A
problem could be well advanced before you even knew it existed. For
another, even with an attic with reasonable venting, with the attic
real cold, I wouldn't be surprised to see local condensation close to
the fan. Then if you do have a problem and mold gets established, the
consequences can be extremely costly. And if you go to sell the house
and it gets a home inspection, a fan venting into the attic is just
about guaranteed to get flagged.

"Todd H." wrote in message ...
"racarson" writes:

The bathroom fan should be vented to a roof cap.

Best Regards,
--
Todd H.
http://www.toddh.net/

It can also be vented horizontally thru the side of the house like a dryer
vent or it can be exhausted downwards thru a soffit.

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