Fireproofing sprays are designed for use on wooden surfaces such as doors, walls and ceilings. They contain chemicals that resist burning, but they don't necessarily prevent a fire from starting. Flame retardant sprays are designed for use on fabrics, carpets, cushions and other soft furnishings that may come into contact with flames or sparks. They contain chemicals to slow down the spread of fire. This is particularly important in homes where there's an open fireplace or wood-burning stove.