Condensation Behind Large Mirror in Garage
Would the following scenario result in condensation/mold behind the mirror/drywall and hence be a bad idea?
-Install a large sheet mirror (5’x6′) on a garage wall.
-Garage wall is a wall that separates interior of home from garage.
-Garage wall is NOT the exterior wall of the garage that separates garage from “outside”.
-All garage walls, and above ceiling, are insulated.
-Garage has NO hvac.
Therefore, is there’s enough of difference of temperature/conditions etc. that the concept of warm air + cold surface = condensation and hence mold on drywall likely to eventuate in this scenario?
Or, because the wall isn’t a fully fledged exterior wall there is enough “fat” to cushion the scenario and a mirror on such wall would be ok?
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Replies
Roger,
Where are you located? in cold climates, garages are often cold enough in winter, that a cold-side vapor barrier will collect condensation. Mold is less likely to grow in cold conditions, but there are certainly times in the shoulder seasons where moisture collected in cool weather could grow mold before it dries out in warmer weather. Also, unconditioned garages in many regions run damp - pretty close to condensation conditions. Anything that slows drying could push you over the edge from just damp to wet enough to grow mold.
Location is climate zone 4a north Arkansas.
Wall cavity is blown in fiberglass, no vapor barrier, just 2x4 framing with standard fiberglass blanket to hold insulation.
The mirror is on the garage side of the wall.
Would a problem be more likely under which scenario???
A. WINTER:
garage is cold side with low humidity.
Other side of wall is warm; with higher humidity than garage?
B. SUMMER:
Garage is warm side with high humidity; other side is cold with lower humidity than garage?
Essentially, would it be best advised not to install a mirror or would it be ok?
Could it be fine if an air gap was made between mirror and drywall; about 1/8"-1/4" from spacers or channel frame at bottom and top of mirror without mirror glued to wall?
Would such a channel, no glue set up, result in the mirror bending and fracturing?
Moisture would accumulate when the garage is less than about 46F. The air gap will make it OK.
Thank you Jon,
If no channel support and mold occurs when garage is about less than 46F, where would mold likey occur?
A. Between mirror and drywall?
B. Backside of drywall holding mirror?
C. Backside of interior drywall/other side of interior wall cavity?
D. Other?
I'd say on either side of the drywall that is in contact with the mirror. When it warms up enough for mold growth and before it dries to the interior.
Interesting thoughts, but I still haven't figured out how to get rid of condensation on the mirrors in the bathroom, lol. Now I practice the treatment of mirror surfaces with liquids and aerosols that prevent fogging of windows and mirrors in cars, glasses, etc. However, I should note that after repairs in the bathroom and the purchase of Modern Bathroom Mirrors https://zabranio.com/top-8-modern-bathroom-mirrors-by-zabranio/, condensate settles sharply on my mirror. Perhaps it was originally made using some special technologies, but it is the new mirror that practically does not fog up.