hand-applied finishes). To apply stucco, begin at the top of the wall and work down. Make sure the crew has sufficient personnel to finish the total wall surface without  joinings  (laps  or  interruptions). Curing The  curing  of  stucco  depends  on  the  surface  to which it is applied, the thickness if the material, and the weather.   Admixtures   can   be   used   to   increase workability, prevent freezing, and to waterproof the mortar. Using high-early cement reduces the curing time required for the cement to reach its initial strength (3 days instead of 7). Air-entraining cement is used to resist freezing  action. COMMON FAULTS There are times when the finish you get is not what you expected. Some of the most common reasons for discoloration  and  stains  are  listed  below: Failure to have uniform suction in either of the base  coats; Improper mixing of the finish coat materials; Changes in materials or proportions during the work; Variations in the amount of mixing water; Use  of  additional  water  to  retemper  mortar;  and Corrosion and rust from flashing or other metal attachments and failure to provide drips and washes on sills and projecting trim. CERAMIC TILE LEARNING OBJECTIVE: Upon completing this section, you should be able to identify the different types of ceramic tile and associated mortars, adhesives, and grouts, and state the procedures for setting tiles. Ceramic  tile  is  used  extensively  where  sanitation, stain resistance, ease in cleaning, and low maintenance are desired. Ceramic tiles are commonly used for walls and  floors  in  bathrooms,  laundry  rooms,  showers, kitchens,  laboratories,  swimming  pools,  and  locker rooms.  The  tremendous  range  of  colors,  patterns,  and designs  available  in  ceramic  tile  even  includes three-dimensional  sculptured  tiles.  Extensive  use  has been  made  of  ceramic  tile  for  decorative  effects throughout  buildings,  both  inside  and  outside. CLASSIFICATIONS Tile is usually classified by exposure (interior or exterior) and location (walls or floors), although many tiles may be used in all locations. Since exterior tile must be frostproof, the tiles are kiln fired to a point where they have a very low absorption. Tiles vary considerably in quality among manufacturers. This may affect their use in  various  exposures  and  locations. SIZES Tile  is  generally  available  in  the  following  square sizes:  4  1/4  by  4  1/4,  6  by  6,  3  by  3,  and  1  3/8  by 1 3/8 inches. Rectangular sizes available include 8 1/2 by 4 1/4, 6 by 4 1/4, and 1 3/8 by 4 1/4 inches. Tile often comes mounted into sheets (usually between 1 and 2 square feet) with some type of backing on the sheet or between the tiles to hold them together. Tiles with less than 6 square inches of face area and about  1/4  inch  thick  are  called  ceramic  mosaics. Ceramic mosaic tile sizes range from 3/8 by 3/8 inch to about 2 by 2 inches, and they are available from the manufactures in both sheet and roll form. Often, large tile is scored by the manufacturer to resemble small tiles. FINISHES Tile finishes include glazed, unglazed, textured (matte) glazed porcelain, and abrasive. Glazed and matte glazed finishes may be used for light-duty floors but should not be used in areas of heavy traffic where the glazed surface may be worn away. Glazed ceramic wall tiles usually have a natural clay body (nonvitreous, 7-to  9-percent  absorption),  and  a  vitreous  glaze  is  fused to  the  face  of  the  tile.  This  type  of  tile  is  not recommended  for  exterior  use.  Glazed  tile  should  never be cleaned with acid, which mars the finish. Use only soap  and  water.  Unglazed  ceramic  mosaics  have  dense, nonvitreous  bodies  uniformly  distributed  through  the tile.  Certain  glazed  mosaics  are  recommended  for interior use only, others for wall use only. Porcelain tiles have a smoother surface than mosaics and are denser, with  an  impervious  body  of  less  than  one-half  of 1-percent absorption. This type of tile may be used throughout  the  interior  and  exterior  of  a  building.  An abrasive finish is available as an aggregate embedded in the surface or an irregular surface texture. Tales  are  available  with  self-spacing  lugs,  square edges,  and  cushioned  edges  (slightly  rounded)  (see 7-19