The pros and cons of different tile backers

Dry-Pack Mortar

This is the traditional tile backer. First, felt paper is stapled to the floor and covered with expanded metal lath. Then cement, sand and water are mixed together to a crumbly consistency and floated over the lath to form a flat surface.

Given the complexity, its easy to see why even experienced tile setters avoid dry-pack mortar and use backer board instead when they can. But a mortar bed does have advantages. There is no cutting or fitting of boards, and a mortar bed is good for leveling and flattening uneven or out-of-level floors, which are common in old houses. If you are good with a trowel and understand how to set up and use screeds as a guide for leveling or forming the mortar, pouring a traditional mortar bed may be a good alternative to tile backer board, especially on uneven or sloping floors.