Hello community. My house is under 2 years old. The tiles on the balcony seem to be excreting some type of residue from the grout. It occurs where the tiles join, which leads me to believe it is tile / grout related. A pressure hose has not worked and the stain seems quite stubborn. I don’t want to simply paint over it without addressing the underlying cause. Any advice would be very much welcomed
Welcome to the Bunnings Workshop community. It's a pleasure to have you join us, and thank you for sharing your question about grout stains on your render.
I totally agree with your assessment. The grout has slowly melted away in the rain and has started to travel down your rendered wall. You can clearly see that it is in line with the tile grout line. This phenomenon often occurs when the tiler does not seal the grout from the weather. I suggest trying out this repair procedure, use a Josco 3 Piece Hand Wire Brush Kit on the grout line and see if it will come off. If the grout stain is too stubborn, I'm afraid I can only suggest painting over it.
I also recommend using CPC 220ml Shower Plug Sealant. It will seal both grout and tile from the weather. My best advice is to make sure to seal all the exposed tile and grout surfaces including the edging of the tiles.
Please remember to use personal protection such as gloves, goggles and a mask when sealing the grout and tile.
If you have any other questions we can help with, please let us know.