What is this staining on can lights?!?

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Billbill84

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IMG_1100.JPG Hi all. So the title says it all. I noticed today (only lived here since January) that two of my many canned lights in finished basement have this weird syrup looking staining on the can so I removed bulb and ring and it's clean inside the cans with the exception of some small dead spiders and a little web activity. What is this from? Anyone ever seen this before?
 
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pjones

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It looks like condensation. Is this in a washroom? Can you feel air getting pushed through it? Could it be missing a vapour barrier if it’s is an area that requires one?
 

Billbill84

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It looks like condensation. Is this in a washroom? Can you feel air getting pushed through it? Could it be missing a vapour barrier if it’s is an area that requires one?
I can't see anything above it because of the drywall ceiling. However when I removed the bulb and outer ring, I can feel a slight draft of cool air and its cold outside. This light is in line with the only other light that had the same staining which means it's same ceiling joist cavity both these lights with staining are in. Maybe a crappy rim insulation spot in the area between the two joists wisking some air in? Why would it condense in the light though? Is this a summer time phenomenon going on or is itwhen it's cool out and the heat generated by the light causing condensation? There's no rust or anything inside the cans though so maybe the basement had high humidity at some point?
 

Steve123

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Maybe a crappy rim insulation spot in the area between the two joists wisking some air in? Why would it condense in the light though? Is this a summer time phenomenon going on or is it when it's cool out and the heat generated by the light causing condensation?
Good hypothesis. Could be a joint in the rim board along that bay, and then crappy sealing/insulation. Or you might have crappy sealing everywhere.

The air in the house is warm and moist. If your trim rim is cold, moisture will condense on it. Turning on the light will warm the metal ring and prevent condensation on it. Could happen either winter and/or summer, depending on exactly your HVAC conditions and local outdoor conditions.
 

Sparky617

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The ring is likely colder due to the draft and moisture from your basement is condensing on the ring. It then attracts dust leaving the stain. I suspect your can is not IC rated (insulation contact) so any insulation isn't up against the fixture. Since you're using CFLs, heat is not really a concern anymore. You could seal up around the can and the drywall to cut down on the drafts.
 

pjones

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The ring is likely colder due to the draft and moisture from your basement is condensing on the ring. It then attracts dust leaving the stain. I suspect your can is not IC rated (insulation contact) so any insulation isn't up against the fixture. Since you're using CFLs, heat is not really a concern anymore. You could seal up around the can and the drywall to cut down on the drafts.
What if this is done and the next home owner goes to put incandescent back in the fixture? It could create a fire hazard. Or years down the road when the kids try to be helpful and use what the sticker says it’s rated for... insert any other possible scenario.
 

Steve123

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You could seal up around the can and the drywall to cut down on the drafts.
Ideally, you would seal up at the source of the cold air entering your home. If you seal up around the light, sure your light stays warmer, but you still have cold air blowing into your house.
 

Billbill84

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What is the exact fire hazard? I don't think I'm gonna seal anything up until I know for sure and I was here last summer and winter and never saw it actually wet on the can so maybe it's the condensation issue summer or winter before the previous owner began running a dehumidifier? I know they went a long time without one because my mechanical room in basement center has unfinished ceiling in there and there's a little exposed duct work that ALL has calcium deposits in it which means they were completely unaware that moisture was higher in that room and was condensing on the duct work as was I when last summer I saw condensate on mechanical room ducts. Since I put a slightly overkill 70pt LG dehumidifier in that room with the same one on other side of basement in the open, the duct condensation is gone. Maybe this phenomenon was tied into all that other mess?
 

Sparky617

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What if this is done and the next home owner goes to put incandescent back in the fixture? It could create a fire hazard. Or years down the road when the kids try to be helpful and use what the sticker says it’s rated for... insert any other possible scenario.
What would happen is the thermal cut out would trip, it would cool down, the lights would come back on, until it trips again. It would repeat this until the owner swapped the bulb. Incandescent bulbs are going away. LEDs are much more efficient and last a lot longer. Though the newer ones don't seem to last as long as the first ones.
 

pjones

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What would happen is the thermal cut out would trip, it would cool down, the lights would come back on, until it trips again. It would repeat this until the owner swapped the bulb. Incandescent bulbs are going away. LEDs are much more efficient and last a lot longer. Though the newer ones don't seem to last as long as the first ones.
I’m aware of the thermal safety. Unless it’s some knockoff allibaba purchase then it should have one. But then you are relying on that safety, and hoping that a home owner will put two and two together before it becomes a problem or unnecessary service call. I’m not a fan of creating situations that could put someone in a position where they rely on a safety to protect them. In my line of work I see safeties fail all the time. All I’m saying is it could create a hazard by having insulation touching it if it’s not approved for it. If the OP is going to go that route of opening up the ceiling to vapor barrier and insulate the cavity then they may as well install an insulation box around the fixture if the manufacturer makes one for that pot, or replace the lights at the same time to one that is approved for direct contact. That should also keep the insurance company happy if there ever was a fire or issue resulting from those lights.

Just my opinion.
 

Billbill84

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Thanks for all info guys I really appreciate it. As of now, I'm not going to seal up anything until I monitor it throughout the seasons and confirm whether or not this is a past issue or reoccurring.
 

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