Hello, Would it be possible to change bulbs and replace with florescent type? That would lower the temperature and maybe stop the condensation.
Good Luck Woodbutcher

A fluorescent lamp might be cool but its built-in ballast can get hot in a recessed fixture but that's irrelevant since moisture condenses on cold surfaces rather than hot ones.

Remove the fixture trim and try to get acess to the gap between the edge of the sheetrock and the fixture. Push a straightened coathanger wire up thru this gap and try to get a rough idea of the distance between the sheetrock and the roof.

If the space between the sheetrock and the roof is less than 11" then you are probably out of luck. You will need to have at least 4" of insulation over a fixture to have any hope of stopping the condensation. I have never seen a 6 or 7" recessed fixture less than 7" high.

If by some chance you do have that much room. Insulating the fixtures you have (if they are IC rated) or replacing them with IC rated fixtures MIGHT solve your problem. You will still have less insulation over the fixtures than over the rest of your ceiling and the fixtures may still be a little cooler than the room.

One method to seal the fixtures is to buy the cheap 12 pack styrofoam coolers and put them over the fixture in the attic. You can cut them to fit around rafters or anything in the way and use spray foam to hold them in place and seal them. This saved 5-7 cfm per light of air leakage on IC housings. I know it might not or does not meet fire retardant code so it is something to check into for your area.

Less than 2 bucks each and a can of foam for every 2-3 lights its pretty inexpensive home sealing.

" It is a sloped ceiling with nothing above it-no attic-just roof. "

I had assumed this is a sloped cathedral ceiling.

I'd reckon that you have moist air getting through the ceiling drywall at the can light locations, then that moist air is cooled as it gets into the colder cathedral ceiling bay, condenses, then the condensate is dripping back into the room.

Go to the home center or lighting store and ask for "air tight IC cans".

Air-tight means the can itself is essentially sealed tight versus the other cans that are full of perforations. Plus it'll usually be gasketed where the can sits against the ceiling drywall. "IC" means the can is rated for direct contact with insulation.

Turn off your humidifier.

Remove your existing can. Check for water damage/wet insulation in the bay. Let things dry out.

If needed you can stuff new insulation in the hole.

Add the new IC can, caulk the rim of the can where it meets the drywall. Add the trim kit.

Your situation is why I never recommend any penetrations in a cathedral ceiling. Can lights are cathedral ceiling killers in terms of violating the thermal and vapor envelope of the house.

Catherdral ceilings are seldom correctly detailed, can lights in them make the matter even worse.

Mongo

Thanks for all the replies. A little more info for you. It is a vaulted ceiling(to 18') and the light is out of reach of our 10 ft. ladder. There is no attic or occupied space above the ceiling. We have a new roof(tear-off, 2006) so it is not a roof leak and this started before the new roof was put on. When it first hapened we automatically thought it was a roof leak and called in a roofer. When he saw the light leak he immediately said it wasn't the roof but condensation from the light so I guess it is more common than I thought. We really seldom use the lights so perhaps we should just have them removed.
We got the humidifier because our house is so dry in the winter furniture was shrinking so much the spindles from my kitchen chairs actually fell out! And we got shocks from everything we touched so I don't want to turn that off if at all possible. I'd rather get rid of the lights. I live in the Buffalo, NY area. Right now it is 17 degrees out so the humidifier is set at 10.

take them out!!

IF you were changing them out you would need to buy an ICAT recessed can (insulation contact air tight)

if you retrofit them you need an air tight insert that fits inside the existing recessed can by removing the trim
and hooking air tight insert by springs to make the can air tight,
then caulk housing of recessed can to sheetrock and reinstall trims..don't buy air tight trims,,this only addresses the gap at the sheetrock to the can.
the major holes in IC cans are in the housing..thus the insert is needed.
To purchase them you will need the brand name and model number..
and you'll need a taller ladder cause this info is inside the can when you remove the light bulb.

if you keep your recessed lights and retrofit them..buy made in USA cfl's they will last longer and keep you off that ladder.those made in china ones don't last.

best of luck.

I have a very similar situation...same style of roof, 7 canned recess style lights and it has leaked since house built in 2001, builder said I needed a dehumidifier, got one..still had a problem..replaced the vaulted style portion of the house's roof in 2014 it fix leak related to the dormers.. I am thinking about contacting a spray foam insulator for a bid...I personally do not know how to tell if the cans are insulation contact (IC) type of cans.