QUESTIONCan Ceramic Tile be Installed over CMU (concrete masonry unit) block? - Can I install Ceramic tile over a CMU wall?
ANSWERANSWER - Yes you can install ceramic tile over CMU (concrete masonry unit) blocks.
You need to properly prepare it to make sure it is free of any structural cracks, clean, and plumb. You can bond the tile directly to it or you can fasten metal lath and apply a scratch and brown coat of mortar.
For a direct bond to the CMU, it is recommended to skim coat it with the thin-set mortar to smooth it out prior to applying a liquid applied waterproof/crack isolation membrane. Then use a high performance modified thin-set mortar exceeding ANSI A118.4 and make sure you achieve 95% contact bonding the tile to the membrane. Then grout it. To see a list of manufacturers who produce tile installation products go to our website at www.CTaSC.com and go to the Resource and Links page and there will be a list with links to their websites. Good luck.