10.1 General
The scope of work includes supply and installation of ceramic tiles for walls in accordance with the finishes schedule mainly to the following
areas:
Bathroom and toilets Kitchen and pantry areas
All other areas as shown in the finishing schedules
The tile material specification given in the following is intended for the purpose of quoting for installation only. The actual tile material will be specified by the interior designer in due time.
10.1.1 Relevant standards
Conform to the following British Standards and codes of practice where applicable:
BS 5385 Wall and floor tiling
BS 5980 Specification for adhesive for use with ceramic tiles and mosaics.
BS 8000, Part 2 Code of Practice for wall and floor tiling BS 6431:Part 9:1984 Ceramic floor and wall tiles.
10.1.2 Samples and literature
Samples and/or literature of proposed adhesive, sealants and grouts to be submitted to the Engineer for approval.
10.1.3 Shop drawings
Provide detailed shop drawings of the tiling installation for the approval of the Interior Designer. Shop drawings are to show the following:
i. floor plans showing tile layouts, floor gulleys and any other relevant floor
ii. Wall elevations showing tile layouts, mirrors, sanitary fixtures and any other, relevant wall fixtures.
Tile designs will be issued by the Interior Designer prior to preparation of shop drawings.
10.2 Materials
10.2.1 Tiles
Tiles shall comply with the following minimum requirements in all respects:
10.2.1.1 General Areas
Fully vitrified tiles conforming to R10, non-slip, resistant to oil, grease, and lyes.
10.2.1.2 Fully vitrified ceramic floor tiles
Pressure strength min 150 N/m sqm.
Bending strength min 20N/m sqm.
Water absorption max. 3%
Abrasion (=wear group 4) max 12 cc/50 c sqm.
Note: In order to reach the necessary breaking and impact strengths, a minimum thickness of 15mm is required.
All tiles to be submitted for Client approval.
10.2.2 Adhesives
10.2.2.1 Adhesives for floor tiling works
Thin set latex mortar composition adhesive shall be used in accordance with the following characteristics:
Shear bond 3.5 MPa (500 psi)
Shear bond water immersion 2.3 Mpa (340 psi)
Water absorption 4% max
Compressive strength 34.5 Mpa (500 psi)
TLA service rating extra heavy
Tensile bond (BS 5890) 1575 N (355 lbs) Shear adhesion (14 days) 22.8 kN95126 lbs) Coefficient linear thermal expansion 65 x 10-7/(° F)
117 x 10-7/(° F)
All materials to be mixed and applied strictly in accordance with the manufacturer’s written instructions.
10.2.2.2 Grout Compounds
Grout system shall be epoxy based stainless grout. Grout shall comply with the following characteristics:
Stainless, pigment free colourfast epoxy grout suitable for floor and wall installations of ceramic tile, brick and stone.
Tensile strength 17.7 MPa (2577 psi)
Compressive strength 101 Mpa (14700 psi) Thermal shock resistance 7.6 MPa (1100 psi)
Shrinkage 0.07%
Sag resistance pass
Water cleanability > 80 minutes
The completed system should carry a full warranty from the supplier.
10.2.2.3 Adhesives for bathroom areas
Adhesive shall be two part latext modified as per manufacturers specification.
10.2.2.4 Grout compounds for bathroom areas
Grout system shall be epoxy based stainless grout as per manufacturer's specification. The grout shall comply with the following characteristics:
Stainless, pigment free, colour fast epoxy grout suitable for floor and wall installations.
Tensile strength 11.7 MPa (1700 psi)
Compressive strength 51.7 Mpa (7500 psi) Thermal shock resistance 7.6 MPa (1100 psi)
Shrinkage 0.19%
Sag resistance pass
Water cleanability > 80 minutes
10.2.3 Joint sealant, back-up strip, performed joint and grout As recommended by BS 5385.
10.2.4 Cement
Ordinary Portland cement complying with BS 12 or Omani Standard No. OS7.
10.2.5 Sand
Clean sharp sand complying with BS 882 (grading Zone 2 or 3).
10.2.6 Water
Clean potable water shall comply with specification for Concrete Work.
10.2.7 Mortar for floor tiles Thin-set mortar as specified here in.
10.2.8 Separating membrane Polythene sheet, 250 microns thick.
10.2.9 Grout
Proprietary grout as recommended by tile manufacturer. Colour to match the tile and to the approval of the Engineer. The grout shall be water resistant.
10.3 Execution
10.3.1 Preparation
Ensure that surfaces which are to receive tiling are free from lose or friable material, are perfectly clean and dry and will provide an adequate key for bedding.
All surfaces to receive tiling to be left for at least 14 days after erection/ casting before tiling work is commenced.
10.3.2 Setting out
Carefully set out tiling joints prior to starting to minimise tile cutting; avoid unduly narrow cut-off; and ensure alignment of vertical and horizontal joints.
All wall tiling shall be laid with continuous joints running in both directions unless otherwise instructed by the Engineer.
10.3.3 Tolerances
The maximum permitted tolerance for finished tiling will be 3mm when measured under a 3m straight edge unless specified otherwise.
10.3.4 Fixing of wall tiles 10.3.4.1 Fixing Pattern
Tiling work to the walls shall be laid in orthogonal or diagonal pattern or as indicated in the drawings. The width of the borders shall be adjusted individually to suit the laying of the tiles. (Pattern to Architect’s drawing).
The joints of the border tiles shall correspond to the joints of the adjacent border tiles.
Where pattern are indicated to be diagonally laid, the setting out of the diagonal grid shall start from the central axes of a wall or as indicated on the respective drawings. All tiles must be laid in a full square pieces or a half-diagonal piece at 45 degree angle, with no exception. However, all borders width must not be more than half the diagonal measurement of a tile.
Where patterns are indicated to be laid in orthogonal pattern to the axes, it must be laid parallel to the axes, the setting out shall start from the central axes of a
wall or as indicated on the respective drawings. The joints of all tiles must correspond to the joints of the adjacent tiles.
10.3.5 Fixing of wall tiles
10.3.5.1 Thick bed adhesive method
Generally wall tiles are to be fixed using the thick bed method as detailed by BS 5385: Part 1.
Apply adhesive as a floated coat to a thickness of approximately 6mm or as recommended by adhesive manufacturer.
Press tiles, which must be perfectly dry, firmly into position within stated working time of adhesive. Tiles may be buttered prior to fixing if so recommended by adhesive manufacturer.
Use adhesive in strict accordance with manufacturer’s instructions.
Note: Alternative wall tile fixing methods (thin bed systems or sand/ cement mortar system) may be used only if so approved by the Engineer.
10.3.5.2 Cement mortar method
Setting out on site shall be to Engineer’s approval in accordance with approved drawings.
Wall tiles shall conform to BS 6431 including all angle fillets, beads, etc. Tiles shall be obtained from a maker approved by the Engineer. Corner tiles shall have finished edges.
Thin bed tile adhesives shall conform to BS 5980. Grout shall be to the approval of the Engineer.
Jointing mastic shall be a 2-pack polysulphide mastic conforming to BS 4254.
Wall tiling shall be carried out in compliance with BS 5385 for internal wall tiling in normal conditions.
Tiling shall be applied to rendered block or concrete walls which have been allowed to thoroughly cure and dry initially for at least two weeks. Unless otherwise scheduled, glazed tiles shall be applied to a rendered surface.
Preparation for wall tiling shall be generally as for internal wall finishes for preparing the background.
Tiling requires true vertical and horizontal alignment of the tiling base. A render coat should be applied as a levelling course. Permitted deviation is 3mm over a 2m long straight edge.
After preparation the wall surface apply a scratch coat of 1:3, cement: sand (0-4mm) omitting any lime additives. This coat to be 3-4 mm thick.
Following the scratch coat apply a render coat of 1:3 or 1:4 cement: sand mix (sand 0.2mm) or a proprietary adhesive in accordance with BS 5980 and approved by the Engineer.
Before fixing, tiles should be soaked in water and then allowed to drain for a minimum of 15 minutes until surface water is removed.
If a cement mortar method is used, fixing should commence within two hours of laying the scratch coat.
Care should be taken not to spread mortar or adhesive over too large a wall area in advance and it is important to check the bonding as the work proceeds by regularly detaching a tile to ensure that at least 65% of the tile back is covered by mortar or adhesive.
Wall tiles should be laid after floor tiles and butt against them neatly. In areas where the floor tiles has a coved skirting, the skirting may be laid first.
Movement joints shall carry through backgrounds to backing structure. Insert backing strip and seal joints with sealing compound to finish flush with surface of tiles.
Corner tiles shall accurately fixed to blend with the surrounding tile work.
Joints shall be sharp and well defined.
Joints between tiles shall be grouted, not less than 12 hours nor more than 24 hours after the tiles have set, with non-staining white cement applied with a brush to fill thoroughly all joints.
Tiles shall be cleaned, taking care to avoid damaging their surface, using one part muratic acid to 10 parts of water. Excess grout shall be removed before it has time to set.
10.3.6 Fixing of floor tiles 10.3.6.1 Fixing Pattern
Tiling work to the floors shall be laid in orthogonal or diagonal pattern or as indicated on the drawings. The width of the borders shall be adjusted individually to suit the laying of the tiles. The joints of the border tiles shall correspond to the joints of the adjacent border tiles of the wall.
Where pattern are indicated to be diagonally laid, the setting out of the diagonal grid shall start from the central axes of a room or as indicated on the respective drawings. All tiles must be laid in a full square pieces or a half-diagonal piece at 45 degree angle, with no exception. However, all borders width must not be more than half the diagonal measurement of a tile.
Where patterns are indicated to be laid in orthogonal pattern to the axes, it must be laid parallel to the axes, setting out shall start from the central axes of the room or as indicated on the respective drawings.
The joints of all tiles installed on the floor shall be in line with the installation of the tiles on the walls and threshold tiles, or as indicated on the drawings.
Where the tile floors meet the plaster walls a 150mm width matching tile skirting, unless otherwise specified, shall be installed to the plaster walls. The joints of the wall/skirting tiles shall correspond to the joints of the border tiles.
10.3.6.2 Fixing Methods
Any of the three following methods (thin bed system or sand/cement mortar systems) may be used if so approved by the Engineer.
a) Thin bed method
Prepare base according to adhesive manufacturer’s instructions and apply adhesive direct to dry base in a layer not exceeding (5mm). Lay dry tiles onto bedding and tamp down (or butter backs of tiles with bedding and tamp down (or butter backs of tiles with adhesive, apply tiles direct to prepared base and tamp down). Leave joints to 3 mm (minimum) between tiles.
In all cases ensure that tiles are solidly bedded without the formation of air pockets.
10.3.7 Quality of tiling
All joints in tiles to be flush. Cutting and fitting of tiles to be done neatly and to connect closely with abutting work. All cuts to be rubbed smooth with a fine stone.
Provide and install round-edge tiles to the top course of all tiled areas and to any exposed vertical edges.
Tiles are to be fitted sufficiently close to plumbing fixtures, outlets, pipes, recessed accessories or other adjacent elements to ensure coverage of the joints by related plates or covers.
Floor tiles to be laid to falls where required.
Round edge tiles to be provided where such edges would be exposed to view.
10.3.8 Grouting
Joints between the tiles shall be grouted not less than 12 hours and not more than 24 hours after the tile is set. Before the grout has set the joints are to be tooled and compacted and the excess grout to be washed and sponged from all sources, care being taken to avoid damage to the tiles, in accordance with the grout suppliers instructions.
10.3.9 Movement joints
Provide movement joints to the full depth of the finish at all wall/floor and wall/ceiling junctions and elsewhere as specified on the Drawings or as
instructed by the Engineer. Movement joints to be to the full depth of the finish and all in accordance with the recommendations of BS CP 202.
10.3.10 Tiled access panels
Provide tiled access panels in tiled areas where access to concealed valves, traps and other similar items as required. Access panel shall be proprietary items such as “Frost” touch latch access doors as specified by F.C. Frost Ltd, U.K. Future Maintenance.
10.3.11 Completion
Thoroughly clean completed tile surface using one part muratic acid to ten parts of water if necessary. Leave tiling free of all imperfections to the satisfaction of the Engineer.
10.3.12 Future Maintenance
As part of the contract, the Contractor shall store in a suitable place as advised by the Engineer/Client an additional 10% of the quantity of tiles used, for future use.
10.4 Special Requirements
10.4.1 Generally
The following specification notes refer specifically to the Entrance lobbies and associated areas. It is the responsibility of the Contractor to ensure that the materials supplied are fit for purpose and to the approval of the Engineer.
All floors shall be true and level unless specified otherwise. Transitions between different floor finishes should be flush and level.
Supply and fix stainless steel finishing strips between all floor element finishes.
The strip shall be Ti-Lock or equal approved and 6mm thick to approved sample.
Grouts should match the colour of the selected floor tile and be in accordance with the detailed specification.
Tiles in showroom area shall be laid in running bond. Rectangular tiles shall be laid with the longest edge of the tile parallel to the main entrance.