Mapei Keracolor U Unsanded Grout 25 lb 27 Silver

This is Keracolor U Unsanded Grout in Silver, an unsanded polymer-modified cement grout meeting ANSI A118.6, ISO 13007 CG2WA. Unsanded, so it is for narrow joints from 1/16" to 1/8". Anything wider wants Keracolor S or Ultracolor Plus FA. Work on about 395 sq ft from a 25 lb bag over 6" x 6" tile with a 1/8" joint. Pot life is about 2 hours. It stiffens after the first hour and can be remixed without more water. Keep heavy traffic off for at least 72 hours. A residential shower or tub surround stays dry for 24 to 48 hours. A steam shower waits 14 days, and anything submerged waits the full 21-day cure. No sealer is required, though one is available. Not over asbestos-containing substrates, and not in joints wider than 1/8". It carries BioBlock against mould and mildew. Being Portland cement it can effloresce, so buff the haze off within an hour or two and go easy on the cleaning water. In stock in Mississauga and Barrie.