Bathroom exhaust fan vent flashing


  #1  
Old 03-01-10, 05:28 AM
J
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Question Bathroom exhaust fan vent flashing

Had the roof done and the sheathing as well. I was planning to install a bathroom vent fan, so the guy doing the plywood cut out a hole in the plywood for a 4" duct(the flexible vent stuff) he simply nailed the duct to the side of the plywood flush with the roof. The roofer was to install the vent flashing.
Now, to my question. I am installing the bathroom vent fan and the duct sit at the plywood line and there is this large domed shaped vent with a cap on top. I don't know what to do. I thought the flashing would slide into the duct then vent to the outside. It seems like the moisture from the bathroom will build up on or in this dome and cap.
I remember buying a vent kit to have it installed and the carpenter installing the sheathing said " Oh no" we would put the duct in and the roofer would do it right after that. Maybe it's right, but it seems wrong. Any ideas? I do not know how to put pictures on this forum. I will try and dig up a web site that show the type of flashing.How will the moisture escape? won't the plywood rot?

Thanks,
J
 
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Old 03-01-10, 10:23 AM
G
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Go outside and look up at the roof, where the vent should be. If you see nothing but shingles, the roofer did not follow through. You need to either get the roofer back or a qualified handyman. If you have the vent, they can position it and properly flash it into the shingles in a few minutes.
 
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Old 03-02-10, 01:00 AM
J
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There is a vent on the roof. There is a hole in the plywood and the duct is attached to the plywood sheathing. The vent is this hollow tapered shap dome with a sort of cap or cover. It seems like the type used to cover vent pipes. The problem is I need to vent the bathroom exhaust. It seems like the moisture will not get outside.
Thanks,
J
 
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Old 03-02-10, 05:20 AM
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It's probably a mushroom vent that is open on the bottom, or it has a lid that will swing open when the vent is turned on. Vents like that have to have a way to keep the rain out, you know.
 
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Old 03-08-10, 06:57 AM
J
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The vent is definetly open at the bottom. The 4" duct is just stuck up inside it. It does not seem like this ios a proper installation. Should there be a pipe going up to diverter the steam from the bathroom closer to the outside word. I worry the moisture will just get trapped between the dome and the plywood. Any ideas?
Thanks,
J
 
  #6  
Old 03-08-10, 06:19 PM
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Right or wrong, you commonly see bathroom fan ducts run up to those type of vents. You do not have to worry about moisture getting trapped, it is venting to the outside.
 
 

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