Welcome to brain Stuff from how stuff works dot com where smart Happens. I am Marshall Brain with today's question, what is this bumpy stuff on my ceiling that looks like popcorn or cottage cheese. The ceilings of many homes and apartments are not painted, but instead are coated with a substance that has this bumpy texture. The treatment is normally called a textured finish or an acoustic finish by builders, but most people refer to it as popcorn. This sort
of ceiling treatment is popular for several reasons. First, it keeps you from having to plaster and sand the ceiling. If you've ever done it, you know that plastering the ceiling is no fun. Second, it hides a lot of imperfections in the ceiling. The ceiling is a huge, flat, uninterrupted and well lit expanse. Any imperfection is immediately obvious. The texturing hides imperfections very effectively. Third, it helps to
eliminate echo in a room. If you've ever walked into a room before and after carpeting, you know what a big difference carpet makes on echoes and acoustic finishes. Like carpeting the ceiling, there are many different ways to put a texture on a ceiling, but the most common technique involves mixing some sort of lumpy aggregate, either vermiculite or polystyrene in with ceiling paint. The mixture is then sprayed
onto the ceiling using a special spray gun. It goes on in one coat, and once it dries, you're done. For more on this and thousands of other topics, Because a House Stuff Works dot com