I can see some logic in this as the typical thin set material is rigid, and fiberglass can move this would cause the bond to eventually breakdown. I am sure there is a suitable mastic material that is rated for outdoor use and will remain flexible. My stepson set tile for almost 20 years, I will ask him if he knows how to do this. NOTE: he cannot do the job as he signed a 'non compete' contract with where he works now.
__________________
Pennsylvania, for 60+ years, most recently, Allentown, now TV. 
|