Caulks and sealants are compounds that fill gaps, cracks, and holes to keep out pests, drafts, and water. They are used to fill small gaps, seams, and joints, such as those found around bathroom fixtures, or finished window and door molding. They also improve energy efficiency and provide a finished look by sealing holes where cold air could escape. Patching and repairing compounds fix imperfections and fill small cracks in surfaces such as drywall, plaster, concrete, masonry, and wood. Spray foam sealants expand to fill wide gaps, such as those found around door frames and pipe.