Staining around recessed light fixtures

Does anyone know what is causing the stains around the fixtures on the cathedral ceiling? Home is built in 2006.






The hold around the can light was not sealed. The home is probably pretty air tight and is sucking air and contaminants from the attic into the home. Seal the area with low-expanding foam insulation.

Good advice!

I would also remove the light bulb to confirm that an IC (insulated ceiling) label is present.

Darn you guys are good.
By the way it is a good reminder to check those cans in the attic and remind people not to use incandescent bulbs but stick to par spots as the white inside reflectors are usually plastic that can burn and melt.

can lights comparison.jpg

can lights comparison.jpg

Close, but actually IC stands for “insulation contact”.

Normally air enters the can light and doesn’t come out of it. But if you have a big enough supply leak and a tight enough house you could be getting a negative pressure situation in the house. Often in colder climates the cans are a void in the insulation and can allow lots of moist air to travel through the can. This can condensate on the metal and drip down. It also can rot framing in non vented or poorly vented cathedral ceilings.

The cans are not sealed.

Sucking or Blowing Steven.
The attic should be static. load able to evacuate RH easily.

If it is soot from the attic it is blowing into the conditioned space. (The pics show a little issue.)
At a low rate by the particulate build-up.
Pour attic venting system ?
Negative pressure in the home?

All homes breath to a certain degree. Inhale and exhale.
Mechanical conditioning, attic and wall venting and shear loading all play a roll.

Ghosting can be a common factor for homes.
Wall, ceiling opening; Lighting, sconces recessed can lighting fixtures , electrical outlets can tell you about the homes overall venting.

Questions I ask myself.

  1. What type of heating system? Forced air draft and ducting balanced?
    The returns all open.
    Chimney soot on the crown or cap speaks in volumes about over all balance…
  2. The attic venting system correct. (how many are?)
  3. The exterior envelope sealed? I spend time on Windows. Caulk!!
  4. Fire place. How often do they use it.

True as I always think of it as Insulation Can touch it.

I learn something new every day, thanks.

Thank you for all the information.