Case 4

Good Practices

• Avoiding efflorescence and other chemical staining requires controlling the flow of water through the construction by ensuring that water-excluding details are effective during the life of the building.
• Sealing and caulking, appropriate flashing and waterproofing is necessary at the edges of tiling work where the tiles are terminated or connected to other structural component to prevent water ingress.
• The migration of salts may be prevented by coating with a waterproofing agent before the cladding is fixed.
• The render or the setting bed mortar should be cement and sand in the proportion of 1:3 with an appropriate mortar additive which will give the render high compressive strength, high bond strength, low water absorption, same coefficient of thermal expansion as concrete and no contribution to flame or smoke.
• The set mortar should be cement and sand in the proportion of 1:1 with a good tile setting liquid. The tile setting liquid should be such that it gives the set mortar characteristics similar to the mortar bed and to BS EN 12004-1. This mortar is to be applied with a trowel in a scrapping motion. The surface of the mortar is to be combed with a notched trowel and the excess mortar removed.
• Only as much mortar should be applied as can be covered while mortar surface is still wet and tacky.
• The tile should then be placed and beaten properly to insure complete bedding and to level the surface of the installation.
• Tiles are then to be aligned to exhibit uniform joints and allowed to set until firm. Excess mortar is to be cleaned as soon as possible from the surface of the tiles.
• The joints are then to be grouted and they should be packed full and free of all pores and pits.
• The excess grout should be cleaned from the surface of the tiles with water and a damp sponge.
• High performance sealant with backer rods behind should be used at junctions between brick tiles on concrete beams and brick walls
• Adhesive mix with too short pot life should not be used especially if delay due to tedious work sequence is inevitable.
• If possible, ensure the full involvement of the adhesive supplier.
• When required, curing should be provided according to the manufacturer’s specification. Follow the manufacturer’s specification when tiles are used on external façade.
• The application of water repellent is recommended to prevent water from seeping into the tile bed, which will reduce the adhesiveness of the tiles to the substrate.