Renovation Issues

[Elkski]

My example of finding day workers you find and hire for 800 baht was fiction.   I was basing this off what I sometimes do here in USA.   I go to a certain home Depot and pick up day laborors.  Many have cars and are in the country legally.   I provide all materials and tools and close supervision.  Pick up, lunch and drop off at train station with fare if they dont have a pass.   I many times work along side them but most work as hard as any worker I've ever worked with.    I actually thought about trying to be the schluter distributor in Thailand at one time. It's a German company.   I forget the brands of edging I have seen used in Thailand.    I see ardex has a Thai website.   Ardex is best known for paint on coatings and such.   They show a decoupling membrane on the US site but not Thailand. https://www.ardexamericas.com/product/ardex-ui-740-flexbone/

 

https://ardex.co.th/

 

The popularity has really been growing in the US but new products are adopted slowly by some trades people who have been doing it the same way for 30 years.  Usually water leaking failures in showers don't show up for 20-30 years.  Long past home warranty periods.   It adds cost and another step that requires following the products lable.  Between a membrane and a tile you need to use unmodified thinset.  

Back to OP.   Pile of sand huh.   Shounds like they were going to use the dry mud bed method.   And worse they probably would have mixed the cement bags and sand right on the floor in a big pile like I witnessed before.   Dry mud beds are great to slope shower floors and such and great with membrane on top with integral membrane drain flange.  And tied into membrane going up the walls.  This is how I do it.  But there is a certain ratio of ingredients and complete mixing I did not observe with the 4 guys with shovels and 1 cu m of sand pile method.  There are many  companies making decoupling membranes as they don't want to be dinosaurs.   Look at the cross section of ditra by schluter.  It has a trapezoid shape that allows a locked in thinset while allowing lateral movement.   The bottom had a fuzzy  under surface for adhesion to the substrate via a bonding layer of thinset.  It usually come in meter wide rolls.  For water proofing a 100mm wife tape is thinset on the Sean's and can go up the walls and hidden behind tile or base moulding.   

[Elkski]

Many good tile guys on YouTube and great forums.  Johnbridge.com is the best place.  So many horror stories just like this one.  And many tile pros help homeowners fix them.  I hate to use the word hate but I hate the old this is how we did it for 30 years line.  I disagree that these products are to lower labor costs.  They are to improve quality.   Tiles are so big now.  2x4' is common now.   I hated installing 18-24" ers because they break your back.  Now they have suction cups with battery's and vacuum assist. IMHO flooring is the base for everything and I see it as more or less permanent.  I used to worry about flooring meeting some height I thought was important.  Now I say do it right and deal with step up transitions.   You soon become used to transitions to 2 cm.   It does require planning to order the right transition's as they target different heights and usually come in 3- 4 meter segments and you may only need 1 meter.   If transition is to wood I make them myself.  I also know people hate the idea of expansion joints every 7 meters in a big room.  But they make some with  different colors of plastic expansion filler to match you grout color.    Also many tiles have 2 nubs on each face to provide a minimum spacing.   I know in Thailand many times the spacing is like 1/2 mm or almost touching.   I admit that looks good but makes a membrane even more of a necessity.  I use a leveling system and they work well but can't do miracles.   To me the laser system is most important tool I use.  So much better than any line.   A flat floor after SLC is a dream to work on.  One thickness of thinset and the tile will level up so easy.   Trying to make a floor level with varying thinset thickness is an art and most times there is a max and minimum spec on these thinsets that gets violated.  Thinset is not a hole filler.  

I've had to fire subs before. It's no fun and for sure adds time and expense  One time cops were called.  Cop told me this happens more than you would think.   The main thing is to remove all of the defective work so a good job has a chance going forward.   I made that mistake before.