Darker spots on ceiling drywall any issues with this?
 

It's not too noticeable but under the right lighting conditions and viewing angle, you can see some subtle darker spots (or hue) on the white ceiling drywall.

the dark spots reveal lines like where the attic/ceiling framing wood (beams or joists?) would be, and around IC rated recessed lighting. The attic has fiberglass insulation sitting atop the ceiling alongside the framing, and has 2 vents on roof and one gable vent along the wall outside

Is that expected/normal or indicate not good installation of attic or the drywall ceiling? Moisture/condensation problem? Or darken from heat in the attic or recessed lighting?

I can post a photo later though can't tell yet whether photo can show the subtle dark spots.

Has the drywall been painted?

Some soot staining occurs along joists and fasteners---they are cold spots--condensation on the cold spots will pick up air born soot--and stick there---

Smokers---candle burners and wood stove users need to paint more frequently because of that.

Mike is right:thumbsup:

It's called ghosting, Google it.

Thanks for the info. That makes sense. When we toured the house one day for inspection (while previous owners were there) we saw condensation on some windows, and owners were cooking (w/o vent fan on) & drying clothes @ the time, so could be ghosting & soot.

If painting, just paint over or need cleaning w/ bleach, etc. Treating the soot/discoloration like mold/mildew?

No bleach, it's just dirt- as Mike said. Page 11: https://docs.google.com/viewer?a=v&q...BiEiG1lHFDd9yA

Gary