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Bill Christens-Barry
 
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Default Venting bathroom fan to ridge vent - is it ok?

I live in a one story house with an unfinished attic. Currently, the
bathroom fan is vented by a 3" PVC duct that passes through the attic
and out the roof. The attic gets cold (blown in rock-wool insulation
lays between the foor joists) and the humid air being vented from the
bathroom condenses. Unfortunately, the PVC is sloped the wrong way so
condensate is dripping back through the fan and into the bathroom.
Messy, and damage to the bathroom ceiling is occurring.

I'm planning to replace the fan with a quieter one with more volume, and
I'd really like to avoid having to put another hole in the roof, and I
also don't want to use the present ducting.

A builder who helped with some other renovations has told me that it's
ok to run the fan exhaust duct (it'll be 4" diam) up to just beneath the
ridge vent, and to allow the exhaust to vent through the ridge vent. Is
this likely to work, and is it an acceptable way of venting? I wonder
about blowback and about iceing during the winter.

Also, is it reasonable to insulate the exhaust ducting to minimize
condensation within it?

Thanks for any comments or suggestions.

Bill Christens-Barry

--
Wm A Christens-Barry, PhD
Equipoise Imaging, LLC

http://www.eqpi.net/eqpi/
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SQLit
 
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"Bill Christens-Barry" wrote in message
...
I live in a one story house with an unfinished attic. Currently, the
bathroom fan is vented by a 3" PVC duct that passes through the attic
and out the roof. The attic gets cold (blown in rock-wool insulation
lays between the foor joists) and the humid air being vented from the
bathroom condenses. Unfortunately, the PVC is sloped the wrong way so
condensate is dripping back through the fan and into the bathroom.
Messy, and damage to the bathroom ceiling is occurring.

I'm planning to replace the fan with a quieter one with more volume, and
I'd really like to avoid having to put another hole in the roof, and I
also don't want to use the present ducting.

A builder who helped with some other renovations has told me that it's
ok to run the fan exhaust duct (it'll be 4" diam) up to just beneath the
ridge vent, and to allow the exhaust to vent through the ridge vent. Is
this likely to work, and is it an acceptable way of venting? I wonder
about blowback and about iceing during the winter.

Also, is it reasonable to insulate the exhaust ducting to minimize
condensation within it?

Thanks for any comments or suggestions.

Bill Christens-Barry

--
Wm A Christens-Barry, PhD
Equipoise Imaging, LLC

http://www.eqpi.net/eqpi/


This is a question for you local building authority. Personally I would
consider using the old pvc and insulate it. I would not want a fart fan
venting into the attic, cause around here that is not acceptable. Hence the
roof penetrations.

Your going to have some problems with the 3 inch pipe. Everything I have
seen recently is 4 inch or larger.

alternate solution vent to the eves.


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Joseph Meehan
 
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Bill Christens-Barry wrote:
I live in a one story house with an unfinished attic. Currently, the
bathroom fan is vented by a 3" PVC duct that passes through the attic
and out the roof. The attic gets cold (blown in rock-wool insulation
lays between the foor joists) and the humid air being vented from the
bathroom condenses. Unfortunately, the PVC is sloped the wrong way so
condensate is dripping back through the fan and into the bathroom.
Messy, and damage to the bathroom ceiling is occurring.

I'm planning to replace the fan with a quieter one with more volume,
and I'd really like to avoid having to put another hole in the roof,
and I also don't want to use the present ducting.

A builder who helped with some other renovations has told me that it's
ok to run the fan exhaust duct (it'll be 4" diam) up to just beneath
the ridge vent, and to allow the exhaust to vent through the ridge
vent. Is this likely to work, and is it an acceptable way of venting?
I wonder about blowback and about iceing during the winter.

Also, is it reasonable to insulate the exhaust ducting to minimize
condensation within it?

Thanks for any comments or suggestions.

Bill Christens-Barry


It get's done that way, but it is a very poor idea.

I am guessing you are talking about eave vent which is what many do.
Most of the warm moist air just ends up in the attic causing trouble.

If it is the ridge (top of the roof) that may be better, but again there
will be more warm most air in your attic that should be there. Do it right
and put it through the roof.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math


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Joshua Putnam
 
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If you get condensation in the exhaust duct now, I expect you'll get
condensation in your attic if you vent it within the attic, even at the
ridge vent. That's bad -- not just ice in winter, but water that
promotes rot and mold.

--
is Joshua Putnam
http://www.phred.org/~josh/
Books for Bicycle Mechanics and Tinkerers:
http://www.phred.org/~josh/bike/bikebooks.html
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twfsa
 
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Vent it to the eve's, where there is a vent,If you go to the ridge(peak)
won't the condensation still run down the tube into the bathroom, had mine
that way (eve) for 11 yrs, just replaced the fan in the bath this weekend,
covered the 4" tube with extra insulation. I installed a 130cfm, Nataluis
$99.

Tom


"Bill Christens-Barry" wrote in message
...
I live in a one story house with an unfinished attic. Currently, the
bathroom fan is vented by a 3" PVC duct that passes through the attic
and out the roof. The attic gets cold (blown in rock-wool insulation
lays between the foor joists) and the humid air being vented from the
bathroom condenses. Unfortunately, the PVC is sloped the wrong way so
condensate is dripping back through the fan and into the bathroom.
Messy, and damage to the bathroom ceiling is occurring.

I'm planning to replace the fan with a quieter one with more volume, and
I'd really like to avoid having to put another hole in the roof, and I
also don't want to use the present ducting.

A builder who helped with some other renovations has told me that it's
ok to run the fan exhaust duct (it'll be 4" diam) up to just beneath the
ridge vent, and to allow the exhaust to vent through the ridge vent. Is
this likely to work, and is it an acceptable way of venting? I wonder
about blowback and about iceing during the winter.

Also, is it reasonable to insulate the exhaust ducting to minimize
condensation within it?

Thanks for any comments or suggestions.

Bill Christens-Barry

--
Wm A Christens-Barry, PhD
Equipoise Imaging, LLC

http://www.eqpi.net/eqpi/





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John
 
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Just inslate the existing pvc pipe in the attic




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Joseph Meehan
 
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twfsa wrote:
Vent it to the eve's, where there is a vent,


And some will go out the vent and some will go into the attic and make
trouble. Even some that does go out will come right back in. The normal air
flow is IN the eaves and OUT the high vents.

If you go to the
ridge(peak) won't the condensation still run down the tube into the
bathroom, had mine that way (eve) for 11 yrs, just replaced the fan
in the bath this weekend, covered the 4" tube with extra insulation.
I installed a 130cfm, Nataluis $99.

Tom


"Bill Christens-Barry" wrote in message
...
I live in a one story house with an unfinished attic. Currently, the
bathroom fan is vented by a 3" PVC duct that passes through the attic
and out the roof. The attic gets cold (blown in rock-wool insulation
lays between the foor joists) and the humid air being vented from the
bathroom condenses. Unfortunately, the PVC is sloped the wrong way so
condensate is dripping back through the fan and into the bathroom.
Messy, and damage to the bathroom ceiling is occurring.

I'm planning to replace the fan with a quieter one with more volume,
and I'd really like to avoid having to put another hole in the roof,
and I also don't want to use the present ducting.

A builder who helped with some other renovations has told me that
it's ok to run the fan exhaust duct (it'll be 4" diam) up to just
beneath the ridge vent, and to allow the exhaust to vent through the
ridge vent. Is this likely to work, and is it an acceptable way of
venting? I wonder about blowback and about iceing during the winter.

Also, is it reasonable to insulate the exhaust ducting to minimize
condensation within it?

Thanks for any comments or suggestions.

Bill Christens-Barry

--
Wm A Christens-Barry, PhD
Equipoise Imaging, LLC

http://www.eqpi.net/eqpi/


--
Joseph Meehan

26 + 6 = 1 It's Irish Math


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HerHusband
 
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Vent it to the eve's, where there is a vent,

Joseph is right, some of the moisture from the bath fan can get sucked back
into the attic through the eave vents.

I'm planning to replace the fan with a quieter one with more volume


I can highly recommend Panasonic fans. They use squirrel cage fans and are
VERY quiet. We have three in our house and are quite happy with them.

I'd really like to avoid having to put another hole in the roof


I tried to minimize roof penetrations in our house too. We only have two, a
large plumbing vent pipe and the woodstove chimney.

Our bath fans get ducted through the attic and exit out through gable end
walls. It's a slightly longer run, but they do not penetrate the roof and
the exhausted moisture isn't anywhere near an eave vent to get sucked back
into the house.

is it reasonable to insulate the exhaust ducting to minimize
condensation within it?


Yes, and slope the ducting towards the exterior vent so any condensation
can drain away. Best to use rigid ducting like PVC rather than those
flexible corrogated things.

In our case, the ducting runs through a heated area, but I would insulate
the ducts otherwise.

Anthony
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Default Venting bathroom fan to ridge vent - is it ok?

replying to SQLit, venter wrote:
venting to the eves is one of the worst ideas in the world. eves bring air in
which is completley counter prouductive

--
for full context, visit https://www.homeownershub.com/mainte...ok-581636-.htm


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Default Venting bathroom fan to ridge vent - is it ok?

On Tuesday, May 15, 2018 at 10:14:06 PM UTC-5, venter wrote:
replying to SQLit, venter wrote:
venting to the eves is one of the worst ideas in the world. eves bring air in
which is completley counter prouductive
--


You're too late, 13 YEARS AGO, SQLit died of fart gas poisoning. He never properly vented his bathroom. It was a real tragedy. His gerbils really miss him. 8-(

[8~{} Uncle Sad Monster


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Default Venting bathroom fan to ridge vent - is it ok?

In alt.home.repair, on Wed, 16 May 2018 03:14:02 GMT, venter
m wrote:

replying to SQLit, venter wrote:
venting to the eves is one of the worst ideas in the world. eves bring air in
which is completley counter prouductive


The subject line is about venting to the ridge vent, not the eaves.

My house has that. I never use the bathroom fans so I don't know how
well the exhaust works, but I don't get any air coming in either.
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Default Venting bathroom fan to ridge vent - is it ok?

replying to HerHusband, CarolinaMike wrote:
I was looking for a solution to bathroom venting without penetrating my new
roof. The roofer recommended soffit venting, but I feared moisture coming back
into the attic. Gable venting makes the most sense and I thank you for the
solution. A little slope and probably a dryer vent cover with flap. Makes
sense to me. Thanks.

--
for full context, visit https://www.homeownershub.com/mainte...ok-581636-.htm


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Default Venting bathroom fan to ridge vent - is it ok?

On Saturday, April 20, 2019 at 4:44:05 PM UTC-4, CarolinaMike wrote:
replying to HerHusband, CarolinaMike wrote:
I was looking for a solution to bathroom venting without penetrating my new
roof. The roofer recommended soffit venting, but I feared moisture coming back
into the attic. Gable venting makes the most sense and I thank you for the
solution. A little slope and probably a dryer vent cover with flap. Makes
sense to me. Thanks.

--
for full context, visit https://www.homeownershub.com/mainte...ok-581636-.htm


What's the issue with penetrating the roof? As long as it's done correctly
there is no issue. And with new shingles it's even less of an issue, it's
very simple. Of course it would have been better to resolve all roof issues
before the shingle job.

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Default Venting bathroom fan to ridge vent - is it ok?

replying to CarolinaMike, Bobby wrote:
Soffit vent works well. How would moisture get back in the attic? It blows
down and had a check valve to prevent backflow.

--
for full context, visit https://www.homeownershub.com/mainte...ok-581636-.htm


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Default Venting bathroom fan to ridge vent - is it ok?

On 2019-04-21 12:14 p.m., Bobby wrote:
replying to CarolinaMike, Bobby wrote:
Soffit vent works well.Â* How would moisture get back in the attic?Â* It
blows
down and had a check valve to prevent backflow.

soffit vented , lol


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Default Venting bathroom fan to ridge vent - is it ok?

On Sunday, April 21, 2019 at 3:14:06 PM UTC-4, Bobby wrote:
replying to CarolinaMike, Bobby wrote:
Soffit vent works well. How would moisture get back in the attic? It blows
down and had a check valve to prevent backflow.

--
for full context, visit https://www.homeownershub.com/mainte...ok-581636-.htm


The soffits are or should be vented to allow air into the attic. Cooler
air goes in there and exits via a ridge vent or similar at the peak
to ventilate the attic.
So, if the bathroom vent is pumping out air, it's not hard to imagine
that some of it will wind up going into the attic. Is it the worst thing,
that could create a problem? I doubt it. But it might not be allowed
by current code either, IDK.



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