Premixed Grout & Thinset Warning

Be Weary of Taking Shortcuts

Premixed tile products are often marketed to the do-it-yourselfer as a no mess, no hassle alternative to conventional cementitous tile mortars. Over the years, a large number of complaints connected to the use of these types of products have been brought to our attention, prompting us to publish the following information:

• Premixed grouts have extended drying times and may not harden for days or even weeks after the tile installation is complete. This is because premixed products rely on both evaporation and the tile and substrate to wick or pull the moisture from the product allowing it to slowly harden. Cementitious grout mortar will harden within 24 hours and fully cure within 30 days. Cement hardens through a chemical reaction (hydration) that bonds water molecules to the cement mixture. We advise consumers to avoid using premixed grout products altogether.
• Premixed thinset is not a true thinset mortar but an organic adhesive mixed with an aggregate (sand) which is added to resist compressive stress. Premixed thinsets may be used in place of mastic for non-vitreous ceramic tile installed in dry areas not subjected to foot traffic but should never be used to install floor tile, stone, semi-vitreous, vitreous, or impervious tiles (e.g. porcelain or glass tile).
• Cementitous grout and thinset mortars do require more effort to mix, however, cement has proven itself both reliable and durable over a period of thousands of years. Cementitous grout and thinset mortars are also much less expensive than premixed adhesives and grouts.
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