The process of repairing popcorn ceilings is a messy one. To combat this, furniture, flooring and other surfaces should be covered with tarps. This will prevent the foam or dust residue from damaging these items, and will make cleanup significantly easier. If necessary, use tape and newspaper to protect windows.
Removal of a popcorn texture is a dirty job, and proper eye and nose protection should be worn. Cover all furniture, windows and anything you wish to keep clean, then thoroughly soak the popcorn. This will help soften the material and reduce dust while scraping the texture off with a putty knife. Early forms of popcorn material contained asbestos, a potentially toxic substance. Prior to beginning any in-depth removal, a small section should be removed and sent to a lab for analysis. If asbestos is present, a professional remover should be consulted. When damage is done to the roof, this is most likely the first step to a repair.
Cans of spray on popcorn texture, from light to heavy texture, are available from most home improvement or hardware stores. The process is simple, and requires movement similar to that of spray paint. Consider practicing on a piece of cardboard or something else disposable. This process will help repair minor cracks and damage, but will not be enough if the damage is severe. The cost of spray texture is often too much to cover a large area, so is the best option if damage is limited to a small space. If popcorn is cracked or falling, scraping the existing popcorn may be necessary before applying the new coat.
Applying a paint-on version of popcorn texture is better for larger areas, and is a fairly simple process. A segmented roller is required, as are standard paint supplies such as a paint tray and tarps. The roller should not be moved in a back-and-forth movement; instead, it should go in one direction or it may cause peeling. If one layer is not enough to provide full coverage, let the first layer dry, then apply a second. This technique may be used for large or small areas and may require scraping the old, damaged texture off before applying the new.
A texturing machine is ideal for severely damaged roofs that require an all-new popcorn texture. These machines are available for rent from most home-improvement stores and are the quickest method for applying texture. Compressed air is used to spray the material onto the ceiling, which provides an even coat over large areas. A hopper gun will provide a similar easy-to-apply, even texture, but is intended for small spaces.