On the ceiling in several rooms there are spots. They look like dark shadows. Doesnt look like water spots.?

Question

Not a damp area.

Answer 1

Is there allot of steam from maybe as an example a shower? They might be mold??

And in that case, I think you use bleach to get it off!

Answer 2

it very well could be mold spots that are bleeding thru the drywall, and regarless of wether you use a bleach or vinegar solution, you will still need to find/stop the source of the mold. otherwise it will just return on your repainted ceiling.

Answer 3

Sounds like mould, my dad used to get it in his unit all the time up north.

I've been told a mix of water and vinigar is good for mould as it kills it and it's cheaper than bleach

Answer 4

Try wiping it off if you are going to paint it anyway this wont hurt. If it wipes off like dust or dirt or something, then clean and paint. But if it does not come off or smudges or is in the old paint like a stain of some sort then you should use a coat of stain sealer paint first and then finish paint it with your ceiling paint. Also most painters will give free estimates, call one or two and get  professional advice, then hire him or use his advice to do it your self. If it is some type of mold then use bleach to kill it before you paint or the mold will just grow right through the new paint.