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SwedishRider
Rider on the Storm
Premium
join:2006-01-11
not Sweden
kudos:1

bathroom exhaust- through roof or soffit?

I need to exhaust a 2nd floor bathroom exhaust fan out of my house, and I have 2 options: vent through the roof or the soffit. Anyone have any experience with either? I originally thought soffit would be better so there is less chance for leaks, but consensus seems to be through the roof, like this:

»www.youtube.com/watch?v=gee3itzjOG0


Any opinions? I live in the northeast in a relatively humid area.


08034016
Hallo lisa Aus Amerika
Premium
join:2001-08-31
Byron, GA

1 edit

Roof...

You don't live in a high Humid area trust me i do 80-98%



The E
Please allow me to retort
Premium
join:2002-05-26
Burnaby, BC
reply to SwedishRider

We'll be doing a bathroom remodel in the spring and will be installing a fan - we're going through the roof for sure. We'd rather have the humidity (and occasional stink ) up and away from windows / outdoor living spaces.
--
"All opinions stated by me are solely my views and do not reflect the views of my employer, this site, or even myself depending on my level of sanity at the moment"



fr0sty

@comcast.net
reply to SwedishRider

Due to winter snow accumulation on the roof, we had to run our vents through the soffit.


mworks

join:2006-06-13
Faison, NC
reply to SwedishRider

I think it depends on the situation. Some roofs can be a pain to get to and work with while others are easy. I would do whatever is easiest to install which will also likely be the easiest one to repair should something go wrong.



whizkid3
Premium,MVM
join:2002-02-21
Queens, NY
kudos:9

IMHO, its best to go through the attic to the sidewall under the peak. This avoids the possibilities of a leak, and keeps the humid toilet exhaust away from windows. If one can't do that, then go through the roof assuming their is no issue with snow accumulation.



jjoshua
Premium
join:2001-06-01
Scotch Plains, NJ
kudos:3
reply to SwedishRider

You should run it out the soffit if you want mold.

Otherwise, run it to the roof and make sure that everything is insulated.



SwedishRider
Rider on the Storm
Premium
join:2006-01-11
not Sweden
kudos:1

said by jjoshua:

You should run it out the soffit if you want mold.

Otherwise, run it to the roof and make sure that everything is insulated.
Thanks for all the helpful feedback... seems that roof is the consensus choice, but I do have heavy snow issues, and I read articles like this one that recommends NOT to use roof vents:

»www.inspectapedia.com/interiors/···tion.htm

Are they wrong? I guess it's in perspective, but I don't want to regret my choice...


Lurch77
Premium
join:2001-11-22
Oconto, WI
kudos:4
reply to jjoshua

Ours both vent out the soffit. I don't know what mold you are talking about. We have no problems.

Just to be clear, you are talking about using the proper soffit vent fixtures, right? Not just dumping it in the soffit?
--
Mount up with wings as eagles.



SwedishRider
Rider on the Storm
Premium
join:2006-01-11
not Sweden
kudos:1

1 edit

said by Lurch77:

Ours both vent out the soffit. I don't know what mold you are talking about. We have no problems.

Just to be clear, you are talking about using the proper soffit vent fixtures, right? Not just dumping it in the soffit?
I'm talking about using a soffit vent fixture like this one:
»www.homedepot.com/h_d1/N-5yc1vZ1···Id=10053

EDIT: if anyone has any recommendations for products, please post!


Lurch77
Premium
join:2001-11-22
Oconto, WI
kudos:4

That is what we have for each bathroom. As I said, so far no issues with them. They flow well and I have not noticed any moisture problems in the attic around the venting or soffit.
--
Mount up with wings as eagles.



rjackal
Premium
join:2002-07-09
Plymouth, MI
reply to SwedishRider

said by SwedishRider:

Thanks for all the helpful feedback... seems that roof is the consensus choice, but I do have heavy snow issues, and I read articles like this one that recommends NOT to use roof vents
They're cautioning against using an existing roof vent with a long-run droopy duct. If you install a new roof vent with one-way flap directly above your fan, that would be ideal, provided you install and properly seal the new vent against rain leaks.

Soffit ventilation is OK, but soffits are meant as air intake, not exhaust. In the winter, there is concern that the moisture will "hang out" under the soffit and cause moisture issues.

»www.askthebuilder.com/665_Bathro···ns.shtml

I am planning on installing a fan this weekend, using a rigid duct through the roof, and then insulating the duct with spray foam. I'll post back with lessons learned!
--
Scott Bourne’s iPhones are not insured for acts of God; God is insured for acts of Scott Bourne.

Parneli

join:2004-12-28
Naperville, IL
Reviews:
·VOIPO
reply to SwedishRider

Another vote for sidewall. If that's not possible then roof. I've always heard that soffit is bad not because of the windows, but because that's your intake for the attic. At least some percentage of that high humidity content air is going to flow into the attic.



Jtmo
Premium
join:2001-05-20
Novato, CA
reply to SwedishRider

How well will it work with over a foot of snow on the roof?



SwedishRider
Rider on the Storm
Premium
join:2006-01-11
not Sweden
kudos:1
reply to rjackal

said by rjackal:

They're cautioning against using an existing roof vent with a long-run droopy duct. If you install a new roof vent with one-way flap directly above your fan, that would be ideal, provided you install and properly seal the new vent against rain leaks.
I'm not sure I agree with you, the site said:

"Avoid through-roof bath vent exits: Our photo (left) shows a typical attempt at venting a bath into a ridge vent - this direction of vent exit may seem convenient but we don't like it much.

In the photo (left) the droopy flex-duct will certainly invite bath moisture to condense and run back to the home's ceiling rather than exiting at the ridge.

Our sketch (below) shows a bath vent fan exiting up through the roof.

The through-roof vent approach gives us another roof penetration, a possible leak spot, and it almost assures that condensing moisture will drip down the vent duct and into the bathroom ceiling."


I agree that soffit isn't perfect, but for the 2 quick showers a day taken in that bathroom, shouldn't it be sufficient?


ElminsterOld

join:2009-03-04
reply to SwedishRider

They did neither of those for our vents. They drilled a hole in the wall and just put them outside the window on the wall.



SwedishRider
Rider on the Storm
Premium
join:2006-01-11
not Sweden
kudos:1

said by ElminsterOld:

They did neither of those for our vents. They drilled a hole in the wall and just put them outside the window on the wall.
Was that on the first floor of a 2 story house? I ask because I'm trying to figure out how to vent a 2nd story bathroom out of the side of the house when the exhaust pipe out of the bathroom on the 2nd floor goes into the attic.

Or am I missing something?? In my situation, I only see the 2 options being roof or soffit.

cwm1276

join:2004-01-16
Stillman Valley, IL
reply to SwedishRider

A roof vent shold not be directed into the ridge vent as they are saying. The vent should have it's own vent on the roof as your video shows.



ElminsterOld

join:2009-03-04

3 edits
reply to SwedishRider

We have multiple vents on 2 different stories. They vented the kitchen, basement bathroom, main floor bathroom, and upstairs bathroom all to the wall directly outside from where they come from. They did something like the attached picture for venting.

An option is to take it out of the attic and put it through the wall off the bathroom. I wouldn't imagine it's too much work or too difficult to do. I don't know if it's the 'proper' way to do it but it works.


ElminsterOld

join:2009-03-04

2 edits
reply to SwedishRider

Click for full size
Click for full size
Kitchen vent
Click for full size
Water Heater vent
I found some pictures of how they did it on our house. It would have been easy to vent out the roof or soffits but they choose the wall instead.

1st picture is the upstairs (2nd floor) bathroom
2nd picture is the vent off the kitchen
3rd picture is the water heater vent (painted so it's hard to see)


SwedishRider
Rider on the Storm
Premium
join:2006-01-11
not Sweden
kudos:1

OK, I see how it was done- you have the bathroom vent on the gable end... that's the problem for me... my upstairs bathroom is in the middle of the house with rooms on both sides to the gable ends. I would need to put the vent into the gable end of the house and then snake the exhaust vent in the attic over to it... I'll have to see how long of a run I need, but might be an option.

Guess I needed to see it before I figured it out...

Anyone have a rough idea on the max distance a bathroom fan vent pipe should be?



AVD
Respice, Adspice, Prospice
Premium
join:2003-02-06
Onion, NJ
kudos:1

said by SwedishRider:

OK, I see how it was done- you have the bathroom vent on the gable end... that's the problem for me... my upstairs bathroom is in the middle of the house with rooms on both sides to the gable ends. I would need to put the vent into the gable end of the house and then snake the exhaust vent in the attic over to it... I'll have to see how long of a run I need, but might be an option.

Guess I needed to see it before I figured it out...

Anyone have a rough idea on the max distance a bathroom fan vent pipe should be?
Shorter the better. I guess with properly sized fan and proper pitch in the pipe there is no limit. I my old co-op we had a bathroom vent connected to a radon fan in the attic for noise control.
--
standard disclaimers apply.


rjackal
Premium
join:2002-07-09
Plymouth, MI
reply to SwedishRider

said by SwedishRider:

Anyone have a rough idea on the max distance a bathroom fan vent pipe should be?
As short as possible, but if you have a long run, you might need a bigger fan. Room size AND duct length AND duct geometry determine fan size. Avoid unnecessary 90 degree bends.

Check out this site to figure out what the equivalent duct length (EDL) is, and then size the fan properly based on the room size and EDL. This chart uses Panasonic fans, which you'll then have to translate to CFM.

»lib.store.yahoo.net/lib/rewillia···oom.html
--
Scott Bourne’s iPhones are not insured for acts of God; God is insured for acts of Scott Bourne.


Paulg
Displaced Yooper
Premium
join:2004-03-15
Neenah, WI
kudos:1
reply to Jtmo

said by Jtmo:

How well will it work with over a foot of snow on the roof?
At my parents house, which routinely has 4 ft of snow on the roof, the vent stacks stick up at least 4ft 1in
--
Guilty or Innocent? You Decide... »Pub Games


Pagerboy

@personainc.net
reply to SwedishRider

I have a washroom and the vent into the attic would have the same problem with all the snow and no unsightly 4foot vent stack. I have vented the washroom and the dryer into the soffit, since it is an older house with no intake in the soffit, a room built in the attic and a 50foot run to the nearest wall it was the only way.



tmh

@verizon.net
reply to SwedishRider

said by SwedishRider:

I need to exhaust a 2nd floor bathroom exhaust fan out of my house, and I have 2 options: vent through the roof or the soffit. Anyone have any experience with either? I originally thought soffit would be better so there is less chance for leaks, but consensus seems to be through the roof, like this:
I have a soffit vent. It generally works well. There's no moisture problem, even in winter. I'd imagine that'd be the case unless you run super long steamy baths.

The only problem with a soffit vent is that it exhaust tends to warm the roof where the duct runs just below. In winter after a snowfall, that area melts first, and causes localized icicles to form. Its too small an area to create an ice dam, fortunately.

AsherN
Premium
join:2010-08-23
Thornhill, ON
reply to SwedishRider

When I had my 2nd floor bathroom redone, they mounted the fan on the outside wall. No ducting.