Water damage around bathroom vent fan drywall

Question Icon
Posted by: from Calgary
12/20/2016 at 12:13:02 AM

I just find out there is water damage on one side of my bathroom fan drywall. It happened after we in Calgary get some really cold weather and after warm weather now. It is about 10x30 cm. Water was dropping slowly. I went to the attic, but I can't find any water on or around fend box or cover. There are frost in the attic and I found some insulation was wet due to the melted frost.

Anyone knows what is going on and how much will cost to fix the issue?

Water damage around bathroom vent fan drywall
User Icon
Chris from Colz Electric in Langdon
Date/Time12/20/2016 at 10:09:47 AM

To much sag in your duct, not running fan for long enough, fan not powerful enough. These are all potential reasons. Roughly 450$ for new fan and duct 110 cfm 1.0sones.

User Icon
Date/Time12/20/2016 at 11:58:33 AM

If you got frost in your attic you either have a leak in your vapor barrier or the bathroom fan is leaking into the attic. Another cause may be lack of roof vents. Also the vent pipe from your fan must be insulated to prevent the condensate from leaking back into the fan area.

User Icon
Date/Time12/20/2016 at 12:38:35 PM

Yes I agree with Colin. Your vent pipe from the fan to the outside must be insulated and well sealed. Also check for unsealed areas in your vapor barrier, around your fan or any pot lights you may have in you bathroom ceiling. Every bathroom fan is rated as to what you should have, depending on the Sq.Ft. of your bathroom, a little more is always good. This could cost between $400 and $600 depending if you must change your fan and how much vent pipe you must run and how much room you have to work with in your attic.

User Icon
Albert in Calgary
Date/Time12/20/2016 at 2:22:52 PM

Thanks for everyone's reply. Today I try to fell the gep between the fan and drywall, to me it fells like the water is come from the vent fan pipe. as the weather get warmer, some old condenaation come back from the pipe. if it is the case, how can i fix it? And how much usually it cost if I hire a contractor to do it for me?

User Icon
Date/Time12/20/2016 at 7:35:55 PM

Well first off condensation builds between hot and cold zones, your attic is a cold zone. so its common to have some moisture but having it leak could be 1. fan not able to push the condensation out as was mentioned before. 2. another source of moisture is causing more moisture than normal like a fan not piped outside releasing moisture directly in the attic. insulation should not be wet to the touch and having it wet enough to leak into your bathroom is not good, I would inspect the vent piping for leaks which I would suspect would allow the excess moisture build up in your attic, also fix your vapor barrier around your vent

User Icon
Date/Time12/20/2016 at 9:34:38 PM

Its most likely from the extreme weather we have gotten. The cold created frost in the pipe and then the heat melted it back down into the fan area. This was extreme weather conditions so it shouldn't happen again. Check all connections and make sure insulation is adequate as a precaution. If you get some small yellow staining around the fan area you could try to fixing it by spraying lightly the area with bleach. ( Always best to have a contractor come out and inspect before doing any repairs to make sure there aren't any unforeseen issues)

User Icon
Date/Time12/22/2016 at 12:17:32 AM

To repair drywall discoloration, spray with diluted bleach. If that doesn't work we can scrape and respray the texture on your ceiling for $400. (after the cause of the damage has been fixed of course).

User Icon
Albert in Calgary
Date/Time12/22/2016 at 8:49:45 PM

Thanks everyone for the answer. I am really appreciated your expertise and take the time to answer my question.

Search the TrustedPros directory and discover the best contractors in your area.

Find your home service pro
Great renovations start with a great contractor.

Since 2004, TrustedPros has been helping homeowners find the right contractor for their home improvements and repairs.

Post Your Project

Within hours you'll be comparing offers from top-rated professionals. It's free to post and you're under no obligation to hire.

Trustedpros Inc. does not warrant the accuracy, completeness, safety, legality or usefulness of any Content, or Whether Content is Current and up-to-date, and TrustedPros Inc. Shall have no liability whatsoever with respect to your use or reliance upon any content or for content being removed or otherwise ceasing to be available. Please refer to the terms and conditions of use of this websites for more details.

Get Free Estimates

Post your project and compare offers from top-rated pros.