Chicago is a tile town. Plastic and fiberglass are a *shande*, a soulless submission to the falsity that tile is a maintenance intensive stinking mess. That said, the high skill tile setting that characterized previous generations of tile showers has been replaced with mortar beds applied by the less skilled. Showers turn into mold farms or worse in a few years. Tile shower pan failures are epidemic.
Contrary to popular belief, tile and grout joints (even sealed grout joints) are not waterproof. Moisture that penetrates these areas collects in in the cement/mortar bed of traditional tile showers and is the primary cause of mold and leaks. Traditional mortar beds put the waterproofing under the mortar bed, not the tile; the large mass of all that cement holds moisture. Kerdi puts the waterproofing directly under the tile and the result is tile and grout that don’t hold water and they dry almost immediately.
Kerdi eliminates vinyl pan liners, there’s no fiddling around with double flanged shower drain receptors, no more hundreds of pounds of cement to form, no more clogged weep holes that turn shower pans into mold farms, and there’s a wide range of accessories and options that allow one to make a very personal statement in that singular component of any well appointed bathroom.
So, why do we need to change? Because the old ways hold water and grow mold, cement board substrates are hard to install and they can leak and hold water, and the methods for installation require a skill set that’s largely been lost so tile and shower performance is unpredictable.
Here’s a quick installation sequence that shows the fundamentals.
Here’s a little progression of a bathroom I recently completed showing the basics.
For those that haven’t fallen asleep yet, here’s a video created by Schluter that lays out the specifics.