I agree with the grout comment but if it were just the tiles it would be cosmetic and I would still be able to use it. The bigger issue is that the two layers of the structure separated and air was getting into the fire chamber making it impossible to regulate the temperature. That is why I used the hvac tape to seal the firebox from the outside. It actually worked well and held up well even through high temperature cooks. The final nail in the coffin is that it is starting to crumble. The bottom surface of the top vent never really gets wet but failed first because it is a stress point where the screw is embedded. Based on the cracks that opened up on the top edge of the body and the bottom edge of the lid my guess is when I break it up to haul it out it will break up pretty easily.