We noticed a sudden water leak while deep cleaning the master shower with the removable shower head, and quickly found the culprit - the tile "bench" in the shower had a grout joint that has completely separated on the leading edge facing the water, and that allowed water to get behind the tile.
My concern is how easily water showed up in the downstairs dining room. Should there be waterproofing around the whole shower and behind all tiles to prevent that from occurring? This is a relatively new home (2016) and I'm wondering if I should just reseal and move on, or if this is something worth taking up with the builder who has already told me this is "homeowner maintenance." Also, given I know water went all the way through, at least to an HVAC duct, is that cause enough to remove tile and investigate any other damage?
Thanks in advance.