Latex-Portland Cement Mortar (Thinset)
This information reflects our best understanding of product composition in 2020.
Tile mortar is used to adhere tiles to a substrate. Cement-based mortars are most common and can either be unmodified, modified, or improved modified per ANSI standards. This CP covers a modified dry-set cement mortar that meets or exceeds ANSI...
Tile mortar is used to adhere tiles to a substrate. Cement-based mortars are most common and can either be unmodified, modified, or improved modified per ANSI standards. This CP covers a modified dry-set cement mortar that meets or exceeds ANSI A118.4 and A118.11 and is used for thinset applications. These products can be used for interior and exterior applications, for floors, walls, or countertops, to bond ceramic, porcelain, natural stone, and quarry tiles to a variety of substrates. These products are mixed with water on site prior to application. Unmodified cement mortars may be mixes with admixes which may contain biocides and alkylphenol ethoxylates (APEs).
Some modified thinset mortar products contain pre- or post-consumer recycled materials, such as fly ash or blast furnace slag, which contain toxic heavy metals. Phosphogysum was also identified in a couple of products. The US EPA bans the use of phosphogypsum, a byproduct of the production of some fertilizers, in almost all applications because it can be radioactive, however, phosphogypsum may still be present in imported products. Biocides were not found to be common for products within the scope of this CP but were advertised for some modified and improvide modified formulations, and may introduce additional hazards. Cement mortars that are for large-format tiles, are rapid-setting, pourable, or lightweight are outside the scope of this CP and may have different fillers or additives.