Do you have a raincoat? They might not be as common as they were in the past, since we spend much more time indoors than we used to, but the concept is simple enough to understand. We wear raincoats to keep the rain from getting us wet. In that case it is basically just for our comfort, but in your home, water can do a lot of damage if it gets in the wrong place. Mold and water damage can cost large sums to remedy, so it would make sense to do what you can to protect your home from it. Vapor barriers are an important part of protecting yourself against water damage. Vapor barriers can consist of a paint or of sheets of plastic or paper that are installed to block water from intruding. When applying a vapor barrier in the form of a paint, it is important to cover the wall well to make sure that it functions properly, and the same is the case when it is a sheet. If you rip a vapor barrier when installing it, it no longer does what it is supposed to, so you should be careful when handling these sheets. If you are installing it on a rough surface, it might be worth investing some money in having a thicker sheet.