Probably what you are seeing are thin areas where the flat paint is showing through the eggshell paint. Give the ceiling another coat of the eggshell and see if that takes care of it.

To help the eggshell spread out better and be easier to apply you could use a paint conditioner like Floetrol. You should be able to find this product, or one like it, at the same place you purchased the paint.

Many thanks for helping me with my problem. Painted ceiling does not look uniform because of the powdery and/or wet looking areas throughout..

Sorry that I gave you the wrong information. Checked again and realized I actually used two flat ceiling paints, i.e., the first was white ceiling flat and the second was super white flat. Initially this ceiling was painted with an eggshell finish that was applied several years ago.

Also, I was wondering if the ceiling sheetrock would be damaged by added more products?

I would be most appreciative if you could give me your suggestion to alleviate this problem.

I have some questions for you. What brand(s) of flat paint are you using? Where did you purchase this paint? Did you thin the paint or add any conditioners? If you rub a finger across the ceiling does some power come off? Did the eggshell show signs of problems before you painted?

I suspect cheap paint might be the culprit. The brands I use work very well and I have never had any problems like this when using them. If what I suspect is true then you will need to prime the entire ceiling with a very good acrylic primer, Zinsser 123, and repaint with a very good interior flat paint, 100% acrylic.

No need to worry about damage to the sheet rock from excessive painting. You can paint 50 times without any problems, as long as good primers and paint are high quality.

It's so nice of you to help me with this issue. Here are the answers to your questions:

I used Benjamin Moore, premium interior, 100% acrylic, Super White N215 02–advanced formula. It was purchased at Miller's Paint Store, Albany, NY.

I did not thin or add any conditioners and no powder comes off when I rub the surface.

The old eggshell finish was in very good condition.

As a novice I'm thinking that I may have applied the paint too generously in some areas. If so, can anything be done about it? Should I use a certain nap for the roller?

Can't thank you enough for helping me with this issue. Not everyone is so kind in sharing their expertise.

Have a great day!

Benjamin Moore makes very good paint. It is very possible that what you are seeing is the result of uneven application. The powdery look could be just a lack of sheen and the 'wet' areas the result of the thick application in some areas. Even good flat paint has a very slight sheen.

I would repaint the ceiling, add another coat. This time use a little Floetrol paint conditioner. You can find this stuff at the paint store. It really helps make the paint "smoother" by allowing it to spread out more evenly. It also reduces drag and the stickiness of the paint. To apply the paint you need a good roller cover. I like 100% lamb's wool covers. For a smooth untextured surface use a 1/2 inch cover. All other textures use a 3/4 inch.

The paint conditioner will help you apply an even coat and give you more time to work the paint. Paint the ceiling in small sections from one side to the other, then move forward and repeat. A well loaded roller will easily paint a 4×4 section, maybe a little more.

Give the ceiling 2-3 days to dry after this coat, opening some windows and getting good air movement will help everything dry. You have several coats up there now and paint takes time to fully cure before the final look is achieved.

Hope this helps. Let me know how it turns out.