I thought I was keeping on top of cleaning the floors of my balcony which I had tiled with porcelain tile.

I live in an urban area where there is airborne dirt that accumulates and after a rain I realized that the "dust" I had missed had seeped into the grout of my balcony tiles. I attempted to clean it with a steam mop and it got marginally better.

The group and tiles were sealed but of course that doesn't create an impenetrable bond. I have a call into the GC in terms of his suggestions.

In the meantime any tips?

I could get the grout professionally cleaned professionally?

I could get the grout sealed with something stronger and more impenetrable?

I could theoretically have the grout replaced? But would that solve the problem.

Not sure how to proceed - the irony is that I have light gray grout in my bathrooms which was chosen deliberately to blend in with the tiles and this grout was chosen so that it would blend with the porcelain terrazo white tiles.

Thanks for any advice.

First picture is balcony when first installed and second picture is balcony after I cleaned with a steam mop.

The pictures are murkier and there isn't the residual dirt along the walls as it appears in the photos as these were quick shots snapped behind the glass doors.