Q. I received the new JLC book "Tiling for Contractors," by Michael Byrne, and was dismayed to see that there is no section that addresses hot-mop shower pans, including framing, backing, and pan installation. Why not?

A.Book author Michael Byrne responds: Given that a shower pan is required by code to have a 1?4-inch-per-foot slope, it is virtually impossible to install a hot-mopped pan without the hot tar running down toward the drain. In addition, since hot-tar fumes have been shown to be a contributing factor in testicular cancer, I've used other, better methods - usually a CPVC pan liner and weep drain - since around 1974.