Installing A Ceramic Mosaic Tile Floor To Match Existing Tile

Technical Procedures Disclaimer

Prior to inclusion in GSA’s library of procedures, documents are reviewed by one or more qualified preservation specialists for general consistency with the Secretary of Interior Standards for rehabilitating historic buildings as understood at the time the procedure is added to the library. All specifications require project-specific editing and professional judgement regarding the applicability of a procedure to a particular building, project or location. References to products and suppliers are to serve as a general guideline and do not constitute a federal endorsement or determination that a product or method is the best or most current alternative, remains available, or is compliant with current environmental regulations and safety standards. The library of procedures is intended to serve as a resource, not a substitute, for specification development by a qualified preservation professional.


We’ve reviewed these procedures for general consistency with federal standards for rehabilitating historic buildings and provide them only as a reference. Specifications should only be applied under the guidance of a qualified preservation professional who can assess the applicability of a procedure to a particular building, project or location. References to products and suppliers serve as general guidelines and do not constitute a federal endorsement nor a determination that a product or method is the best alternative or compliant with current environmental regulations and safety standards.



  1. This procedure includes guidance on installing a new ceramic mosaic tile floor to replace lost or severely damaged portions of existing ceramic mosaic tile, or to enlarge or alter an area of existing/historic tile floors.
  2.  Ceramic mosaic tile was introduced in the early 1900s and was commonly used through the 1930s. These tiles were most commonly used in entrance foyers and public lobbies, as well as bathrooms.
  3. Tiles were typically small, white, unglazed, and laid in a bed of mortar. With advancements in technology, the individual tiles were eventually pre-mounted on 12"x12" sheets of paper in decorative patterns. This paper was, at first, face-mounted and removed after the tile sheets were set. This method was later replaced by the use of a fabric mesh backing to hold the individual tiles together. This change made it possible to realign crooked tiles more easily.
  4.  Various shapes were available, including round, square, octagonal and hexagonal. Various colors were also created using clay pigments (for unglazed tile) and colored glazes (for glazed tile).
  5. Ceramic mosaic tiles were usually no larger than 2 1/4" and no thicker than 1/4".
  6. See 01100-07-S for general project guidelines to be reviewed along with this procedure. These guidelines cover the following sections:
    1.  Safety Precautions
    2. Historic Structures Precautions
    3.  Submittals
    4. Quality Assurance
    5. Delivery, Storage and Handling
    6. Project/Site Conditions
    7. Sequencing and Scheduling
    8. General Protection (Surface and Surrounding)

These guidelines should be reviewed prior to performing this procedure and should be followed, when applicable, along with recommendations from the Regional Historic Preservation Officer (RHPO).


  1. The Tile Council of North America, Inc. (TCNA),
  2. American Society for Testing and Materials (ASTM),
  3. American National Standards Institute, Inc. (ANSI),


  1.  Product Data: Product data for each type of product specified.
  2. Shop Drawings: Shop drawings indicating tile patterns and locations and widths of expansion, contraction, control, and isolation joints in tile substrates and finished tile surfaces.
    1. Locate precisely each joint and crack in tile substrates by measuring, record measurements on shop drawings, and coordinate them with tile joint locations, in consultation with RHPO.
  3. Samples:
    1. Samples for initial selection purposes in form of manufacturer's color charts consisting of actual tiles or section of tile showing full range of colors, textures, and patterns available for each type and composition of tile indicated. Include samples of grout and accessories involving color selection.
    2.  Samples for verification purposes of each item listed below, prepared on samples of size and construction indicated, products involve color and texture variations, in sets showing full range of variations expected.
      1. Each type and composition of tile and for each color and texture required, at least 12 inches square, mounted on plywood or hardboard backing and grouted.
      2.  Full-size units of each type of trim and accessory for each color required.
  4.  Quality Control Submittals: Qualification data for firms and persons specified in "Quality Assurance" article to demonstrate their capabilities and experience. Include list of completed projects with project names, addresses, names of architects and owners, plus other information specified.
  5. Design Data/Test Reports/Certificates:
    1. Master grade certificates for each shipment, type and composition of tile, signed by tile manufacturer and installer.
    2. Material test reports from qualified independent testing laboratory indicating and interpreting test results relative to compliance of tile and tile setting and grouting products with requirements indicated.


  1.  Qualifications:
    1. Installer Qualifications: Engage and experienced installer who has successfully completed tile installations similar in material, design and extent to that indicated for project.
    2.  Single-Source Responsibility for Tile: Obtain each color, grade, finish, type, composition, and variety of tile from a single source with resources to provide products of consistent quality in appearance and physical properties without delaying progress of the work.
    3. Single-Source Responsibility for Setting and Grouting Materials: Obtain ingredients of a uniform quality from one manufacturer for each cementitious and admixture component and from one source or producer for each aggregate.
  2. Mock-Ups: Before installing tile, erect mock-ups for each form of construction and finish required to verify selections made under sample submittals and to demonstrate aesthetic effects as well as qualities of materials and execution. Build mock-ups to comply with the following requirements, using materials indicated for final unit of work.
    1.  Locate mock-ups on site in location and size indicated or, if not indicated, directed by RHPO.
    2.  Demonstrate the proposed range of aesthetic effects and workmanship.
    3. Obtain RHPO's acceptance of mock-ups before start of final unit of work.
    4. Retain and maintain mock-ups during construction in undisturbed condition as a standard for judging completed unit of work.
      1. When directed, demolish and remove mock-ups from project site.


  1. Packing and Shipping:
    1. Deliver and store packaged materials in original containers with seals unbroken and labels intact until time of use. Comply with requirement of ANSI A137.1 for labeling sealed tile packages.
    2. Prevent damage or contamination to materials by water, freezing, foreign matter, and other causes.
  2.  Acceptance at Site: Handle tile with temporary protective coating on exposed surfaces to prevent coated surfaces from contacting backs or edges of other units. If despite these precautions coating does contact bonding surfaces of tile, remove coating from bonding surfaces before setting tile.
  3. Storage and Protection: Extra Materials: Deliver extra materials to owner. Furnish extra materials that match products installed as described below, packaged with protective covering for storage and identified with labels clearly describing contents.
    1.  Tile and Trim Units: Furnish quantity of full-size units equal to 3% of amount installed, for each type, composition, color, pattern, and size.


  1. Environmental Requirements:
    1.  Maintain environmental conditions and protect work during and after installation to comply with referenced standards and manufacturer's printed recommendations.
    2.  Vent temporary heaters to exterior to prevent damage to tile work from carbon dioxide buildup.
    3. Maintain temperatures at 50 degrees F. (10 degrees C.) or more in tiled areas during installation and for 7 days after completion, unless higher temperatures are required by referenced installation standard or manufacturer's instructions.



  1.  American-Olean Tile Co.
  2.  Bostik Construction Products


  1.  General:
    1.  ANSI Standard for Ceramic Tile: Comply with ANSI A137.1 "American National Standard Specifications for Ceramic Tile" for types, compositions, and grades of tile indicated.
    2. ANSI Standard for Tile Installation Materials: Comply with ANSI standard referenced with products and materials indicated for setting and grouting.
    3.  Colors, Textures and Patterns: Where manufacturer's standard products are indicated for tile, grout, and other products requiring selection of colors, surface textures, patterns and other appearance characteristics, provide specific products or materials complying with the following requirements:
      1. Provide selection made by RHPO from manufacturer's full range of standard colors, textures and patterns for products of type indicated.
    4.  Factory Blending: For tile exhibiting color variations within the ranges selected during sample submittals, blend tile in factory and package accordingly so that tile units taken from one package show the same range in colors as those taken from other packages and match approved samples.
  2.  Tile Products:
    1.  Unglazed Ceramic Mosaic Tile: Provide factory-mounted flat tile to match original (American Olean Tile Co., Inc.), or approved equal.
    2.  Glazed Wall Tile: Provide flat tile to match original (American Olean Tile Co., Inc.), or approved equal.
    3.  Trim Units: Provide tile trim units to match characteristics of adjoining flat tile and to comply with the following requirements:
      1. Size: To match original, coordinated with sizes and coursing of adjoining flat tile where applicable.
      2.  Shapes: To match original, selected from manufacturer's standard shapes.
  3. Setting Materials (American Olean Tile Co., Inc., Bostik Construction Products), or approved equal.
    1.  Latex-Portland Cement Mortar: Provide materials complying with ANSI A108.1,
      1. Reinforcing Wire Fabric: Galvanized welded wire fabric, 2 inches by 2 inches - W0.3 by W0.3 (16 ASW gage or 0.0625 inch diameter); comply with ASTM A 185 and ASTM A 82 except for minimum wire size.
      2.  Expanded Metal Lath: Provide diamond mesh lath complying with ASTM C847 for requirements indicated below:
        1. ) Base Metal and Finish for Interior Applications: Fabricate lath from uncoated or zinc-coated (galvanized) steel sheet, with uncoated steel sheet painted after fabrication into lath.
        2. ) Configuration Over Studs and Furring: Flat.
        3. ) Weight: 3.4 psf.
    2. Dry-Set Portland Cement Mortar: ANSI A118.1., Manufacturer's standard latex type (water emulsion) serving as replacement for part or all of gauging water, combined at job site with prepackaged dry mortar mix supplied or specified by latex additive manufacturer.
    3. Thin-Set Portland Cement Mortar Installation: Where thin-set portland cement mortar applications are indicated, use Latex-portland cement mortar, complying with TCA requirements for installation method designated, unless otherwise required.
  4. Grouting Materials (American Olean Tile Co., Inc., Bostik Construction Products), or approved equal.
    1. Dry-Set Grout: Comply with ANSI A118.6.
    2. Commercial Portland Cement Grout: Proprietary pre- blended compound composed of portland cement and additives formulated for type of tile installation.
    3. Latex-Portland Cement Grout: Proprietary pre- blended compound composed of portland cement, selected and graded aggregates, color pigments, and chemical additives gaged with latex additive to comply with manufacturer's directions.
  5.  Miscellaneous Materials:
    1. Organic Adhesives, Type I (American Olean Tile Co., Inc., Bostik Construction Products), or approved equal.
    2. Metal Edge Strips: Zinc alloy or stainless steel terrazzo strips, 1/8 inch wide at top edge with integral provision for anchorage to mortar bed or substrate unless otherwise indicated.

2.02 MIXES

  1. Mix mortars and grouts to comply with requirements of referenced standards and manufacturers including those for accurate proportioning of materials, water, or additive content; type of mixing equipment, selection of mixer speeds, mixing containers, mixing time, and other procedures needed to produce mortars and grouts of uniform quality with optimum performance characteristics for application indicated.



  1. Examine substrates and areas where tile will be installed, with installer present, for compliance with requirements for installation tolerances and other conditions affecting performance of installed tile.
    1.  Verify that substrates for setting tile are firm, dry, clean, and free form oil or waxy films and curing compounds.
    2.  Verify that installation of grounds, anchors, recessed frames, electrical and mechanical units of work, and similar items located in or behind tile has been completed before installing tile.
  2.  Do not proceed with installation until unsatisfactory conditions have been corrected.


  1. Blending: For tile exhibiting color variations within the ranges selected during sample submittals, verify that tile has been blended in factory and packaged accordingly so that tile units taken from one package show the same range in colors as those taken from other packages and match approved samples. If not factory blended, either return to manufacturer or blend tiles at project site before installing.


  1.  Installation, General:
    1.  ANSI Tile Installation Standard: Comply with parts of ANSI 108 series of tile installation standards included under "American National Standard Specifications for the Installation of Ceramic Tile" that apply to type of setting and grouting materials and methods indicated.
    2. TCA Installation Guidelines: TCNA "Handbook for Ceramic, Glass, and Stone Tile Installation"; comply with TCNA installation methods indicated.
    3. Extend tile work into recesses and under or behind equipment and fixtures to form a complete covering without interruptions except as otherwise shown. Terminate work neatly at obstructions, edges, and corners without disrupting pattern or joint alignments.
    4.  Accurately form intersections and returns. Perform cutting and drilling of tile without marring visible surfaces. Carefully grind cut edges of tile abutting trim, finish, or built-in items for straight aligned joints. Fit tile closely to electrical outlets, piping, fixtures, and other penetrations so that plates, collars, or covers overlap tile.
    5. Jointing Pattern: Unless otherwise shown, lay tile in grid pattern. Align joints when adjoining tiles on floor, base, walls, and trim are same size. Lay out tile work and center tile fields in both directions in each space or on each wall area. Adjust to minimize tile cutting. Provide uniform joint widths to match existing.
      1.  For tile mounted in sheets, make joints between tile sheets same width as joints within tile sheets so that extend of each sheet is not apparent in finished work.
    6.  Lay out tile wainscots to next full tile beyond dimensions indicated.
    7.  Expansion Joints: Locate expansion joints and other sealant-filled joints, including control, contraction, and isolation joints, where indicated during installation of setting materials, mortar beds, and tile. Do not saw cut joints after installation of tiles.
      1. Locate joints in tile surfaces directly above joints in concrete substrates.
    8. Grout tile to comply with the requirements of the following installation standards:
      1.  For ceramic tile grouts (sand-portland cement, dry-set, commercial portland cement, and latex-portland cement grouts), comply with ANSI A108.10.
  2.  Floor Installation Methods:
    1.  Ceramic Mosaic Tile: Install tile to comply with requirements indicated below for setting bed methods, TCNA installation methods related to types of subfloor construction, and grout types:
      1. Portland Cement Mortar: ANSI A180.1.
      2. Tile Thick-Set Mortar Bed: ANSI A108.1 Specifications. For applications over membrane waterproofing, setting shall be 1-1/4 inch minimum thickness and shall be reinforced with mesh set midway in mortar bed.
      3. Concrete Subfloors, Interior, Waterproofing Membrane: TCNA F121-90.
      4.  Grout: Dry-set.
    2.  Stone Thresholds: Install stone thresholds at recommended locations; set in same type of setting bed as abutting field tile unless otherwise indicated.
      1. Set thresholds in latex-portland cement mortar for locations where mortar bed would otherwise be exposed above adjacent non-tile floor finish.
    3. Metal Edge Strips: Install at locations indicated or where exposed edge of tile flooring meets carpet, wood, or other flooring that finishes flush with top of tile.


  1. Cleaning: Upon completion of placement and grouting, clean all ceramic tile surfaces so they are free of foreign matter.
    1.  Unglazed tile may be cleaned with acid solutions only when permitted by tile and grout manufacturer's printed instructions, but no sooner than 14 days after installation. Protect metal surfaces, cast iron, and vitreous plumbing fixtures from effects of acid cleaning. Flush surface with clean water before and after cleaning.
  2.  Finished Tile Work: Leave finished installation clean and free of cracked, chipped, broken, unbonded, and otherwise defective tile work.


  1.  Provide final protection and maintain conditions in a manner acceptable to manufacturer and installer that ensures that tile is without damage or deterioration at time of substantial completion.
    1. When recommended by tile manufacturer, apply a protective coat of neutral protective cleaner to completed tile walls and floors. Protect installed tile work with kraft paper or other heavy covering during construction period to prevent staining, damage and wear.
    2.  Prohibit foot and wheel traffic from tiled floors for at least 7 days after grouting is completed.
  2.  Before final inspection, remove protective coverings and rinse neutral cleaner from tile surfaces.