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  1. #1
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    Default Bathroom fan venting thru attic

    I have seen quite a few posts about venting bathroom fans thru the attic and out the roof, but have not been able to find any specific instructions. Is a standard sguare roof vent used? What is the preferred method of attaching the 4" flexible duct material to a suitable connection forcing the moist air thru the vent and not leaking out into the attic? Is there a vent that already has a 4" connection on it that is used for this specific application?

    We currently have our fan venting thru the soffitt. I am amazed at how much I have read declaring this practice to be bad. The stores sell the soffitt vents, they must be safe to use right?

    Well, in any case, I intend to change the venting method this spring and am unsure how the connection is made.

    Thanks
    Eric

    I did some internet searching and found that Home Depot stocks a kit made by Broan for roof venting a bathroom exhaust fan. I also called a local Roof Supply store and they sell it as well. I guess I could have done that first, but it is always interesting to try and get responses from others and see if any additional information comes out regarding tips for installation or preferred suppliers.

    Eric
    Last edited by Eric1435; 04-28-2008 at 02:08 PM. Reason: clarification, solution

  2. #2
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    Default Re: Bathroom fan venting thru attic

    Canuck,
    Just finished reading the thread about bathroom fan exhaust options and you had included pics of your recent NuTone installation. Can you tell me from what supplier you obtained the black insulation for the duct? Is that wrapped around a rigid duct and not the flexible duct? I am about to re route ny bathroom fan through the roof from it's current location in the soffit. I have no vertical wall to go through. I want a good roof top vent as well as quality insulation to go around the duct. I have only seen insulation wrapped around a flexible duct.
    I live in Wisconsin and hopefully your supplier in Canada can ship to my state.

    Thanks
    Eric
    Eric ....
    As mentioned in the reply to your private message I would like to do this in your thread .... this way others who may read this can chime in with additional info. or it may help others.

    Just to mention ..... don't use the standard type of roof vents as these are not designed for bathroom exhaust.
    As you mentioned you had discovered the type like Broan offers are designed for this purpose.

    Personally I don't recommend the roof top vents for areas that receive a medium or heavy snow amounts on the roof. Mainly because the vents would be covered and leaving an issue of the snow being melted from underneath and creating a situation similar to ice damns. If at all possible try and run the exhaust vent out a side wall or the gable end wall of an attic .... if available.

    Having said that .... if you will using the roof top method you want the vent to have a tall profile.

    The duct insulation you are asking about is actually insulated flex ducting ..... available at any home supply center .... over top of rigid ducting.

    The reason I did this ..... I feel the inner plastic that makes up the flexiable ducting will provide some vapor isolation between the rigid duct and the insulation wrap. It also helps with ensuring a more air tight seal for the rigid ducting .... plus it's easier to slip over the rigid ducting.

    Hope this helps.

  3. #3
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    Default Re: Bathroom fan venting thru attic

    Thanks Canuk.

    I will do some searching on the net to try and find tall profile roof vents designed for exhaust fan applications. Our big box stores just don't seem to have some of this stuff. Perhaps I can also try and contact a roofing supply house that would stock a good selection of quality products.

    Sorry I added an extra C into your name in my original message.
    Last edited by Eric1435; 04-30-2008 at 02:39 PM. Reason: Misspelled name

  4. #4
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    Default Re: Bathroom fan venting thru attic

    Glad to help.

    If you want ... try a heating/venting contractor and see if they will make a taller profile one out of there heavier gauge galvy sheet metal.






    Sorry I added an extra C into your name in my original message.
    Not to worry .... just don't do it again (kidding)

  5. #5
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    Default Re: Bathroom fan venting thru attic

    [
    The duct insulation you are asking about is actually insulated flex ducting ..... available at any home supply center .... over top of rigid ducting.
    Is the insulation you used actually a sleeve? I just searched using "insulated flex ducting" as my search criteria and most of what I saw was a flexible duct w****d in insulation, which is not what I want. I did see a website that offered insulated sleeves in a variety of diameters and I think that would work. I am not proficient enough to copy the picture nor the website. Novaflex was the manufacturer that advertised sleeves, but it didn't appear they sell to the general public.

    Thanks again
    Eric
    Last edited by Eric1435; 04-30-2008 at 03:01 PM.

  6. #6
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    Default Re: Bathroom fan venting thru attic

    Yep ... that's pretty much it.

    Similar to this in this link http://www.rewci.com/infldu.html

  7. #7
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    Default Re: Bathroom fan venting thru attic

    Similar to this in this link http://www.rewci.com/infldu.html

    The link you provided was actually the fist website I visited, but their product appeared to be the wire flexible duct wrapped in insulation and I wouldn't think this would fit over rigid ducting. Am I wrong?

    Sorry I can't seem to wrap my brain around this.

    So ...in order to do some thinking for myself I went back to the original pics and saw the manufacturer of the flexible duct insulation was Dundas-Jafine. I got to their website and found the US retailers that carry their products. I will check with the retailers they listed for an insulated sleeve to slip over round rigid ductwork.
    Last edited by Eric1435; 04-30-2008 at 04:07 PM.

  8. #8
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    Default Re: Bathroom fan venting thru attic

    Here's the link to the company brand I used ... you'll also notice just the insulted sleeve that also can be used.

    http://www.dundasjafine.com/products...ted/index.html

  9. #9
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    Default Re: Bathroom fan venting thru attic

    Thank you!

  10. #10
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    443

    Default Re: Bathroom fan venting thru attic

    http://www.cetsolar.com/dryervent.htm

    These vents come in 2-section plastic---the curved lower half is removed & not used for bathroom vent roof applications.

    The top section fits onto 4" pvc rigid drain pipe.
    Last edited by JacktheShack; 06-14-2008 at 08:54 PM.

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