Hi MisterSteve,
Your 3/4" t&g OSB installed correctly and in good condition meets all minimum standards as a subfloor for ceramic tiles. Your joists are probably fine too as you said, but do you know their species and grade? L458 from JB's place is based on Douglas Fir or Southern Yellow Pine grade #2. Is the span 13' 0" or a few inches less?
You're probably OK, but you should double check. Be sure to install all CBU's into fresh thinset mortar, fasten and tape all joints.
Jaz
Your 3/4" t&g OSB installed correctly and in good condition meets all minimum standards as a subfloor for ceramic tiles. Your joists are probably fine too as you said, but do you know their species and grade? L458 from JB's place is based on Douglas Fir or Southern Yellow Pine grade #2. Is the span 13' 0" or a few inches less?
You're probably OK, but you should double check. Be sure to install all CBU's into fresh thinset mortar, fasten and tape all joints.
Jaz