When faced with old, damaged plaster walls, one technique to dress up the room is to install drywall over the existing plaster. A drywall overlay gives the walls a smooth, fresh surface that's ready for new paint, paper or trim. This is a common technique used among professional contractors hired to renovate houses bought under foreclosure. For example, real estate companies that invest in foreclosures often deal with houses that are more than 50 years old and exhibit serious signs of aging. The high cost of installing new plaster, or demolishing the existing walls, drives many such companies to hire contractors to overlay drywall as a practical, economical and attractive means to update the home. For more, or to get started on your own drywall overlay project, watch this DIY video tutorial.