Leak in attic causing water damage
To repair a small area where the popcorn has come loose and cover a stain you can do this:
1. Scrape off all the popcorn that has come loose.
2. Use a can of spray paint made to cover stains such as “Kilz” to conceal the stain. Paint only the scraped area and do not allow the paint to hit the popcorn that was not damaged. (Most home improvement centers will carry this in the paint department.)
3. After the paint has dried completely, use a can (or 2 if needed) of spray texture to apply a new coat of popcorn finish over the painted area (spray only the flat area you scraped). Do not use it over any areas that still have the popcorn in place or the texture will become too rough. This texture comes in a spray aerosol can in medium and large textures. Be sure to get the one that matches your ceiling. If you make a mistake you can easily remove the spray texture and try again. WHATEVER YOU DO USE SOME PLASTIC DROP CLOTHS AND COVER EVERYTHING! This spray is under high pressure and will fly everywhere. Wear protection on your eyes, a hat, and even make a poncho from the plastic to cover yourself. It is messy but it does work well. I have used it on numerous occasions. Most home improvement centers also carry this product. I buy it at ***** and Home Depot all the time.
If you need to replace some drywall and want to learn how to do it yourself; go to the Expert Advise area of this website and you can hire a professional to assist you.