# bathroom venting to chimney??



## Trying Handy

Hi everyone,

I live in an old house (built 1911) in Winnipeg, Canada. The bathroom is getting very damp from the shower and I would like to install a fan. Interesting, there is a hole in the ceiling, above the toilet and sink. The hole is countersunk in the plastic and measure about 3 inches in diameter. So, I figured, hey - here's a great place to cut away for a vent (didn't do that yet - still planning). 

I have an un-developed attic that is full of blown-in insulation. Just went up there to see where the hole leads. And there is a metal pipe attached to it, running to the chimney, I think. The pipe looks about the same diameter as the hole. 

It's not easy to get around in the attic because most of the floorboards were ripped out and the insulation is tough to work around.

But my question is this - should I try to work with the existing hole/pipe/chimney and attach a fan to it or should a scrap the whole thing and vent anew?

The chimney is on the west side of the house, and I read that venting should go to the north or east sides only.

Any suggestions would be greatly appreciated.

-Trying Handy


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## Scuba_Dave

How far away is the chimney ?
Does the vent go into the main chimney (for fires or other) ?
...or a 2nd pipe only for the bath exhaust ?


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## Trying Handy

*pipe and chimney*

It's really hard to get at it in the attic, but from what I can tell the pipe stretches about 6 foot to the chimney. The chimney is not used for much except I think the water heater in the basement is attached to it (I remember hearing that from the installer). 

Actually, the chimney looks kind of scary from the outside, almost like it's going to topple one day. As far as I know, there is nothing else being used by the chimney. No fireplace.


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## Scuba_Dave

If the chimney only has single stack & is being used by the water heater..gas ?
Then it can't be used by the bathroom vent
If there are 2 exhaust stacks & the bath & water heater are venting into seperate stacks then you are OK

My chimney has 3 seperate stacks/exhausts:
Oil burner
Fireplace
3rd - unknown


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## Trying Handy

Thank you for the reply. How does one go about checking the number of exhausts in the chimney?


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## Scuba_Dave

I actually went on my roof
But I have a door to the roof & its not steep


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## Trying Handy

I'm not sure if the hot water heater is gas, but I think it is. 

I can understand how that would not be good to mix with other. But the pipe in the attic leads directly to the chimney - is it possible that this is unsafe as it is without a ventilation fan?


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## Scuba_Dave

If its gas hot water & its tapped into the same exhaust as the bathroom it could be dangerous
CO/exhuast could go into the bathroom if there is any downward pressure on the chimney
Not sure how likely that is


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## Gary in WA

Don't use your chimney for the bath fan exhaust. 

Ducting (including enclosed stud bays or joist cavities used to transport air), installed outside the
conditioned space have all seams and joints, both longitudinal and transverse, sealed. (M1601.3.1 &
WSEC 503.10.2)
􀂉 Flex duct supported per manufacturer’s specifications. (M1601.3.2)
􀂉 Metal duct minimum support every 10’. (M1601.3.2)

Insulate exhaust vent ducts with R-4 in unconditioned spaces such as attics and crawlspaces. (VIAQ
302.2.3)

*IMC § 501.2: Exhaust Systems/Independent System Required.* Mechanical exhaust systems for bathrooms must be independent of other exhaust systems.


Check on these for your local area with your Building Department.


Gary


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