benefit of the doubt until the actual cause of the failure is discovered. Up until now this 80% minimum coverage rate has been the death knell for tile contractors. It is unfair and needs to be stopped. Here’s another point to consider. If the coverage on a particular failure was 80%-95% and a crack appeared in the slab causing the tile to shear loose, whose fault would it be? Obviously the con- crete guy’s, right? So who can determine how much lateral stress the cracking of the concrete caused? 100psi, 200psi, 500psi, 1,000psi? It’s humanly impossible to determine, so let’s give the benefit of doubt to the tile con- tractor. Remember, when concrete cracks it’s generally like a mini explosion taking place – sud- den and violent. It is never a silent and gradual separation. I would venture a guess that there are more un-failed and completely success- ful tile installations in this country with less than 80% mortar coverage than there are with it. As profes- sionals, let’s concen- trate on solving failures rather than copping out by simply calculating coverage issues that more times than not unfairly condemn the tile installers. Tom Lynch is a 55-year veteran of the tile industry and one of the NTCA’s initial Recognized Industry Consultants inductees. He can be reached at (336) 877-6951, tom- mydlynch@gmail.com or at www. tomlynchconsultant.com. TECH TALK –––––––––––––––––––––––––––––––––––––––––––––––––––––––––– This floor did not fail for three years until cracks developed in the concrete slab. 48 TileLetter | February 2018