Porcelain vs. Ceramic Tile

For hard-traffic floors and outdoor areas, porcelain is usually the safer choice. For walls and dry interior floors, a good glazed ceramic is a legitimate pick. The defining difference, per ANSI A137.1, is water absorption: 0.5% or less for porcelain by the ASTM C373 test, more than 0.5% for non-porcelain. Both fall in the same planning band of about $10–20 per sq ft installed.

Yes. TCNA describes a "ceramic tile family" defined by the ANSI A137.1 standard, and porcelain is one member of it, alongside pressed floor tile, quarry tile, wall tile, mosaic tile and others. When people say "ceramic" in a store, they usually mean non-porcelain tile.

Look for the Porcelain Tile Certification Agency (PTCA) mark on the box or spec sheet. TCNA says you cannot tell porcelain from non-porcelain by eye, and only a lab test of water absorption is certain. PTCA certification confirms the 0.5% limit. It does not confirm the tile's other properties or that it suits your room.

The tile itself absorbs very little water, but a tile floor is not waterproof. TCNA points out that grout joints are not waterproof, so in a shower or other wet area the installation method and the substrate are what keep water out of the house. A bonded waterproof membrane under the tile (ANSI A118.10 is its specification) does that job, whichever tile goes on top.

Some can. TCNA says porcelain is not the only tile rated for exteriors and that many non-porcelain tiles, such as quarry tile, are rated for outdoor use. Check the maker's "area of use" for the specific product. ASTM C1026 is the freeze-thaw test. TCNA adds that even frost-resistant tile can be damaged when water sits in grout joints or setting-bed voids and freezes, so slope and drainage matter as much as the tile. ANSI A326.3 also notes that an "Exterior, Wet" slip label does not refer to frost resistance.

Neither, as a category. Slip resistance depends on finish and texture. ANSI A326.3 sets a wet DCOF of at least 0.42 for level interior floors expected to be walked on wet, and names polished surfaces as an example of ones that may fall below it. TCNA notes that unglazed porcelain may have better slip resistance than glazed. Ask for the product's DCOF value and declared use category.

TCNA's PTCA bulletin says real porcelain is typically more expensive than non-porcelain tile with the same decorative look, because of its raw materials, energy and equipment. Installed, both fall in the same planning band of about $10–20 per sq ft, because labor, substrate preparation and tile size drive much of the total. Use the cost calculator for your room.

Yes, somewhat. TCNA says porcelain is harder to cut and harder to bond than non-porcelain, but that this makes little difference to you as long as the installer uses the right materials. Polymer-modified thinset mortars meeting ANSI A118.4 or A118.15 are the common choice, and large tiles need full coverage, which means flattening the trowel ridges as each tile is set.

For glazed tile, ASTM C1027 is the ASTM test for visible surface abrasion. It wears the surface with an abrasive load and compares the result with unabraded tile. It only compares tiles of like color and finish. C1027 is written for glazed tile, so it does not rate unglazed through-body porcelain. Ask the maker which rating the product carries and which areas it is rated for.

Not directly. TCNA explains that cracks in concrete reflect through tile bonded to it, and that even small shrinkage cracks can grow as the slab keeps curing. The fix is a crack isolation membrane under thinset tile, or a mortar bed over a cleavage membrane. TCNA also recommends carrying slab control joints up through the tile. This applies equally to porcelain and ceramic.