Looking for suggestions finding schluter products in stores or online. So far have found it at ubuy.co.th and amazon but prices are extreme and selection limited. In case you don't know about them here is an example of an underlayment for tiling.

 

 

Are we allowed to as why this product is necessary? People have been installing tiles over concrete for a very long time?  

 

In US style houses with timber/gyproc construction I can see maybe a need for an impermeable membrane under wet room tiles, is this necassary in the tropics with concrete construction.

 

For most common tiling situations in Thailand there is no need. Some may want schluter as a way to make a waterproof shower on the 2nd floor. Others may want it for an uncoupling layer for laying tiles on a slab that has cracks. For me I want both an uncoupling and waterproofing layer for a flat cement board roof in preparation for floor tiles.