QUESTIONMy porcelain tile floor was flooded with 3 feet of saltwater by Hurricane Ian in Naples FL. There is no visible damage but general contractors have recommended replacement of the tile. Can you help me to evaluate the condition so that I can make an informed decision? Thanks
ANSWERANSWER - Porcelain tile is impervious and cannot absorb more than 0.5% to meet the standards for a porcelain body tile. If the tile was installed correctly and if the substrate is not moisture sensitive, then the tile installation should not be damaged by being submerged in salt water for a temporary time.
Although if you have a plywood subfloor that is subjected to excessive moisture for an excessive amount of time, it is possible it can be affected by the moisture and warp, but you would see damage to your tile. APA rated plywood is resistant to moisture, so it can get wet and dry out. Over a concrete substrate it isn't a concern.
Normally for floods they classify the water quality into 3 categories. Class 3 is the worst classification and is grossly unsanitary as it supports bacteria growth. Class 2 is gray water, which salt water might fit more into, but it can't be used for irrigation like gray water can. The IIRC Water Quality standard doesn't refer to salt water.
The only adverse possibility that I can think of is it could be that when the salt water evaporates it might leave a white mineral residual referred to as efflorescence in the grout joints. Possibly when the floor is later washed it might draw up more minerals.