Attic/insulation/can light moisture

Anyone ever see moisture/condensation like this? Insulation was wet above all of the can lights in the kitchen. Does this mean that lights are non IC rated?

Any help/insight is greatly appreciated.

I have never seen that ether. Was this over the kitchen only? It may be from cooking. Was the exhaust fan over the stove working?

These were the only visible/accessible can lights, there were a few others. The kitchen venting was a over-the-range microwave.

Those kitchen exhaust fans only work if they are turned on. Does it recirculate back into the kitchen? Excess humidity? Is there a humidifier?

I see this once in awhile.

The cold attic and warm/hot recessed lights result in the condensation.
The wet insulation needs to be replaced.

They very well could be non I/C rated. See my pic below as I use this in my reports for illustrating the types.

Was the finishing materials around the lights stained as well?

I would recommend verifying that they are I/C rated. I would also advise that a better repair would be to use track lighting instead of recess lighting. Even the I/C lights can create condensation if the conditions are right.

IC_fixtures Image.JPG


Window condensation on majority of the windows.

Whole house humidifier on the furnace.

No. Only a couple of inches of insulation.

??? Would you do this??? Seems like can lights are extremely popular, while track lighting, well, most people don’t like the look (including me). I think I would have a hard time convincing clients to do this. Home built in 2004, and is on the expensive end.

Can lights are not sealed allowing humidity from cooking(condensation on windows) to escape into attic.Insulation soaks up condensation that forms when the warm moist air meets the cold air in the attic. Can lights need to be sealed and kitchen ventilation needs to be exhausted to the exterior of the home. Also check indoor humidity in other areas of the home. There may be a central humidifier on the furnace that is cranked up and also spewing moisture into the home. 30%-50% indoor relative humidity is recommended.

You have excessive air pressure in that house for that to occur so much.
Leaking HVAC Return Duct over pressurization of the building?

from looking at the picture you posted my opinion of the cause of the wet insulation is excessive heat loss with moisture added (due to being in a kitchen, cooking releases a tremendous amount of moisture). The can lights are not insulated and the insulation should be removed from direct contact of fixture in attic. In order to insulate around the uninsulated can lights you must first build a box over the fixture. Insulation should never directly touch the can light

My thoughts exactly.

So what!?

The issue at hand is the huge amount of water in the insulation.
It will never catch fire from “contact” under these conditions…

Get with the real program.
There is nothing about cooking humidity that will cause this. It is about air ex-filtration.

What kind of bulb’s were installed in the can’s? an improper bulb can also add to the problem.

Current national energy code (recommended) call for all ceiling penetrations to be sealed (caulk between the fixture and the drywall) and sealed can light.

Was there a vapor barrier under that blown in? Probably not.

Remember, a hole will leak more humidity, especially up into an attic (hot air rises and hot air contains more humidity) than drywall without a vapor barrier.

But the vapor barrier is still needed.

I tell people to use spray foam, on the underside of the roof deck, and seal the attic.

Hope this helps;

Also, the IC rating is only with regards to the temp of the can lights exterior. Will it start a fire if the ceiling insulation is blown in cellulose (green, but also mold food :mrgreen: Go figure!)

IC rating says nothing about the fixtures ability to allow air movement.

In my opinion, can lights should be sealed.

Dispelling the Myths of Fire Risk and Mold in Cellulose Insulation

“They very well could be non I/C rated. See my pic below as I use this in my reports for illustrating the types.”

I wouldn’t use that criteria (colour) to determine IC or not. Always look at the label!!

“The cold attic and warm/hot recessed lights result in the condensation.”

“condensation that forms when the warm moist air meets the cold air in the attic.”

The proper description of the phenomenon is:

Warm air containing moisture is leaking upward through or around the light fixture. It condenses when it meets and touches a cold surface. The air is moving upward due to one or a combination of the following:
(1) stack or chimney effect (warm air rises)
(2) mechanically caused positive pressure in the kitchen area
(3) wind pressures on the house

I have for years heard the “on-the-street” phrases of “when the heat meets the cold” or “warm moist air meets the cold air in the attic”.

Dictionary: cold (noun)-the relative absence (or lack) of heat. So our above phrase now becomes “When the heat meets the relative absence of heat” ??? Hot and cold are descriptive terms only. In AC, one ton of cooling refers to removing 12,000 BTU’s (heat) /hour from an area, not adding 12,000 units of cold to the area since there are no units of cold.

If the hot moist air meets the cold air in the attic, we should have clouds forming and and at some point it begins to rain. That’s what happens in the atmosphere.


Have you seen any certified cellulose supporting mold growth or do you have any vaild studies. You seem to have a negative opinion on a great insulator. In Canada, cellulose was the first product to be allowed to use the federal gov “Environmental” approval logo in 1983. That was the year my company stopped blowing fiberglass.

Some IC lights are sealed; many are not (too bad). Can lights should be sealed only by the manufacturer. Do not seal non-IC cans as they have not been tested for the higher temperatures that will result. Being unsealed allows some heated air out of the can (if not improperly covered with insulation) and is part of the cooling process which keep the temps down. Other solutions are available.

Seal the attic??? Are you implying to block the vents? Am I missing something here?