What is a mortar bed?
A mortar bed (or mud bed) is a mix of Portland cement and sand, lime would be added for vertical surfaces, that is normally reinforced with welded wire or metal lath. All of this is typically applied on top of a wooden, gypsum drywall or concrete substrate from ˝” up to 2”, to prepare for the installation of ceramic tile or dimensional stone.
In the past, all tiles were set in a damp or plastic mortar bed. Before the tiles were installed, they were soaked in clean water, usually overnight or several hours. The mortar bed would be installed and while still damp or plastic, the contractor would sprinkle dry Portland cement on the mortar bed, then take the wet tiles and ‘beat’ them into the mortar bed, hence ‘wet set’. The combination of a damp mortar bed, dry Portland cement sandwiched between wet tiles would create a monolithic layer of tile, Portland cement and mortar. If installing a mud bed, for convenience, use TexRite Floor Mud or Wall Mud that is factory blended in a bag instead of mixing cement and sand on the jobsite. See ANSI A108.1A Installation of Ceramic Tile in the Wet-Set Method, with Portland Cement Mortar. Today, most tile or dimensional stone installations utilize a dry-set mortar applied in a thin layer to adhere or bond the tile or dimensional stone to the substrate
What does latex or polymer modified mean?
Latex simply means a polymer suspended in water creating a liquid emulsion. Polymer is used to describe a chain of molecules that impart flexibility and adhesive qualities to the products in which they are integrated. In the context of a polymer modified dry-set mortar, polymer would be a dry redispersible powder that is factory blended into the dry-set mortar, which, when mixed with water, produces a Latex-Portland Cement Mortar. Dry-set mortars mixed with latex or polymer modified dry-set mortars , provide significant improvement to overall physical properties like, bond strength, shock resistance, reduced water absorption and impact. See ANSI A118.4 American National Standard Specifications for Latex-Portland Cement Mortar.
What type of thin-set mortar do I use to install porcelain floor tile?
Porcelain tiles should be bonded with a latex or polymer modified thin-set because of the very low absorption, less than 0.5%, of the tile body. Additionally, porcelain tiles typically have a very hard and smooth surface to the backside of the tile, the bonding side, creating additional bonding concerns. Therefore a latex or polymer modified thin-set is required to set this type of ceramic tile. Use TexRite Porcelain TS, CeramaBond, TotalContact or CeramaFlex as a bonding mortar for porcelain tiles.
After removing the carpet, I have discovered small cracks in the concrete that will be receiving ceramic tile, what now?
Small, surface shrinkage cracks are commonplace on slabs, as long as the crack is not over 1/16” wide; use TexRite CeramaFlex to install the tile. For cracks up to 1/8”, use TexRite UniFlex Elastomeric mortar to install the tile, or treat the entire floor first with TexRite HydroRite as a crack isolation membrane, then install the tile with CeramaFlex
