<p>In Southern California we still call it ‘green board’, although I noticed the brand carried at Lowe’s is actually ‘purple board’. It is marked mold resistant but I doubt it would really make too much difference in a bad situation. </p>
<p>For some reason my tiling guys don’t like ‘cement board’ because it crumbles when cut. They prefer ‘Hardibacker’ which is of course more expensive ! We always put 1/4" hardibacker board on the bathroom floors for tile and 1/2" hardibacker on shower walls.</p>
<p>Every single house there is always a big back/forth on what the shower walls need to be for tiling. Each tiler seems to have a different requirement for what they want. Old timers insist on mold resistant drywall and then spend a whole day doing chicken wire/deck mud on the shower walls before tile. I kept thinking this was a colossal waste of time and went to three different tile specialty wholesale stores and asked them. </p>
<p>Turns out the true requirement is 1) walls have to be solid and not flex, causing tile to crack or fall off wall and 2) walls need to be perfectly level and plumb. </p>
<p>So, to save on labor and material cost we now frame out showers with studs at every 12 inches (instead of 16 standard stud width) - or insert new studs between existing studs. I always tear out any shower to the studs because I’m not buying houses that have lovely clean new tile, and I want to get down to studs to check for mold, etc. And we make sure that every bit of the studs are level and plumb, even if we have to put in shims. This takes about 2 hours of my carpenter’s labor and about $20 in materials (basically 2 x 4s and some nails).</p>
<p>Then we insulate really well, cover with Aquabar tar waterproof paper and cover with 1/2" hardibacker. At this point the walls do not get any sturdier… I tell the tile guys that they have to work with that structure or they don’t need the job. But, always hot mop shower base and they deck mud that for solid structure. (see mistake below!) </p>
<p>Here’s another one of my colossal mistakes in the past… my favorite tiler was too busy and recommended another tiler to do my job. This guy convinced me that we should use the new plastic/rubber liner stuff for a shower pan. I asked him several times if he had experience, knew what he was doing, etc. Even called my original tiler to ask his opinion. Of course he installed this rubber thing when I was not there. Job done, everything looks fine. This was on a condo and we were just redoing bathrooms and kitchens, no electrical or plumbing, no permit required.</p>
<p>Sell the house and one week later (only one week!!), buyer calls to tell me that the dining room ceiling is completely wet and collapsing - under the shower upstairs. Huge disaster on my hands and a $4,000 mistake because I felt so bad about the situation that I let the Buyer select their own tile guy who insisted the ENTIRE shower had to be ripped out and start all over again. I just let them have whatever they wanted because I make sure I stand by my product and it was such a mess.</p>