# This light leaks air into attic, should I cover?



## joecaption (Nov 30, 2011)

Needs to be cover up and there needs to be a hose from the exhost to the outside. Through the roof or out the gable end whatever is closer.
If not your dumping hot moist air into the attic where it's going to cause mold and condinsation.


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## sinistersix (Mar 26, 2013)

Hmmm, well it is only an exhaust fan for the toilet room, rarely used but I do think it needs a pipe installed to the outside. I currently dont see any opening in the attic where I can have a hose go to the outside, what is the best method for this?


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## joecaption (Nov 30, 2011)

http://www.bing.com/images/search?q...7D9B7E80C121EF12E32708AB51F7&selectedIndex=48

Here's a good picture if what can happen without running it to the outside.

As I said it need to be run out through an end wall or out the roof.


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## sinistersix (Mar 26, 2013)

joecaption said:


> http://www.bing.com/images/search?q...7D9B7E80C121EF12E32708AB51F7&selectedIndex=48
> 
> Here's a good picture if what can happen without running it to the outside.
> 
> As I said it need to be run out through an end wall or out the roof.


Wow thats not good. Can I run a flex hose from the vent across to the sofits and aim it down so it vents out the side of the roof or do I need to cut a hole in the side of my house or something somewhere?

Also, my other bathroom vent is the same thing...no vent to the outside. Can I connect both of these in some sort of Y connection and have one house vent outward somewhere or do they need to be separate? Sorry for the noob questions, just never done it before...


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## Gary in WA (Mar 11, 2009)

That pic is very informative! Thanks, Joe.

IMO, the gable end is always better; mass elevation of ducting leads to mass moisture entrapment inside duct, esp. flex, (straight pipe is best) and in snow country, roof vents tend to help create ice dams as they melt snow with room temps. Insulate/vapor barrier the ducting, caulk around the fan/light box at drywall; http://www.bpi.org/Web Download/Ins...Install_Certif_Scheme_Handbook_V1.3_DRAFT.pdf

Gary


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## sinistersix (Mar 26, 2013)

THe good news is that both bathroom vents are on the backside of the house so I can get to the exterior wall really easily...just not sure if I should do one vent per fan or if I can attach them both?

Do I install something like this on the side of the house for each vent? https://www.google.com/shopping/pro...=X&ei=ZvpRUa3IKInliQL93YGoAg&ved=0CIABEPMCMAI


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## joecaption (Nov 30, 2011)

Depends on what type siding you have.
If it's vinyl then it's best to use one with the built in J moulding.
Siding will need to be removed to install it.
http://www.midamericabuilding.com/homeowners/products/details.aspx?id=1268&gid=1176&parentid=1170


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## sinistersix (Mar 26, 2013)

joecaption said:


> Depends on what type siding you have.
> If it's vinyl then it's best to use one with the built in J moulding.
> Siding will need to be removed to install it.
> http://www.midamericabuilding.com/homeowners/products/details.aspx?id=1268&gid=1176&parentid=1170


I do have siding, not sure if its vinyl. There are white pvc pipes all through the attic that are going up through the roof and I assume they are vents...can I just T into one of those or is that a no no?


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## joecaption (Nov 30, 2011)

Those are sewer gas vents, unless you want sewer gases and methane gas going into the room I would not suggest it.
And no the two bathrooms can not be tee together with one vent. The air would just blow into the other bathroom not out the vent.


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## sinistersix (Mar 26, 2013)

joecaption said:


> Those are sewer gas vents, unless you want sewer gases and methane gas going into the room I would not suggest it.
> And no the two bathrooms can not be tee together with one vent. The air would just blow into the other bathroom not out the vent.



Got it, only thing Im not sure of now is that I cant tell if its IC rated or not. It was buried in insulation when I found it so I assume its been ok all the years but I want to do it right. Should I just re bury it or build a box around it if I cant tell if its IC or non IC?


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## Windows on Wash (Aug 30, 2011)

sinistersix said:


> Got it, only thing Im not sure of now is that I cant tell if its IC rated or not. It was buried in insulation when I found it so I assume its been ok all the years but I want to do it right. Should I just re bury it or build a box around it if I cant tell if its IC or non IC?


How old is it and the IC vs. Non-IC is usually stamped on the can.


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## sinistersix (Mar 26, 2013)

I just went up there and looked again, its just a black box. I assume that since the house was built in 1996 and all of the recessed lighting is non IC, that this will also be non IC.

IN this video, the guy says to just insulate around it and duct tape the holes in the box..but if Im going to blow R60 I would want to bury this unit. 

http://www.thisoldhouse.com/toh/video/0,,1630938,00.html

So if non IC, insulate around and foil tape it up or cover it with a box and buy away?


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## Windows on Wash (Aug 30, 2011)

Yes.

Build a box around it and seal the seams.

If the box is higher than the insulation, no need to mark it.

If not, make the location with a marker flag for easier location in the future. :thumbsup:


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## asinsulation (Apr 11, 2011)

You CAN vent them together. They make "Y" connections as well as flappers with gaskets specifically for the circumstance. It can be a little time consuming to get it all together, but sometimes easier then making 2 holes depending on the situation.


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## Windows on Wash (Aug 30, 2011)

asinsulation said:


> You CAN vent them together. They make "Y" connections as well as flappers with gaskets specifically for the circumstance. It can be a little time consuming to get it all together, but sometimes easier then making 2 holes depending on the situation.


We always like 2 holes as well.

if the flapper gets stuck...nobody wants to smell their neighboring bathroom's business.


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## Gary in WA (Mar 11, 2009)

Hey, you are all one family anyway, lol. A duplex/townhouse would not have joined exhaust vents, per fire-separation. Choose one; "A"- https://www.acwholesalers.com/brd10...ion/11990.ac?gclid=CNrUxdqBoLYCFap_QgodajoA_A

or "B"- http://www.ventingdirect.com/contin...-fitting-for-ducted-home-fan-systems/p1471567

I'd go with "B"; designed like plumbing waste fittings, not 1/2 of air-flow needs to turn at almost right angle to vent, lol. Use the straight end of connection for the bath farthest away for optimum pressure loss.
Bath fans have self-closing flappers at the motor to prevent incoming air flow. One duct from the "Y" would help reduce condensation in the whole system. Be sure to insulate the ducting, and a plastic wrap to prevent condensation on/in the pipes. Air/moisture goes right through fiberglass insulation= look at your furnace filters. They skipped that part on TOH video, as did the flashing above and under the next lap siding for water drainage not relying on caulking alone- 6-15 year life. So easy to use a metal roof flash while on the ladder... Par for them, about there, but not quite... I smile a lot while watching them.

Gary


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## operagost (Jan 8, 2010)

joecaption said:


> Those are sewer gas vents, unless you want sewer gases and methane gas going into the room I would not suggest it.
> And no the two bathrooms can not be tee together with one vent. The air would just blow into the other bathroom not out the vent.


Not quite, because bathroom fans have check valves in them (otherwise, wind gusts would blow through as well), but I inheirited that particular configuration in my house and I can say that it hurts the efficiency of the system.


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