I would seal the tile before grouting.
Is it necessary to seal marble tile.
Since it is carrara marble a white marble it can contain embedded iron deposits and you need to seal both the tile and the grout in the shower.
There are a few different circumstances that will require you to seal marble shower tiles.
The process for sealing a marble floor is relatively easy and should take less than an hour with each application.
Tile made from marble travertine granite terra cotta or slate looks beautiful but is susceptible to spills stains and chipping if it is not sealed.
The same process used to seal marble floors can also be used to keep a marble countertop sealed against stains.
While not all marbles are delicate most are highly absorbent and thus easy to stain and etch.
Then grout using non sanded grout.
Unlike a ceramic or porcelain tile floor it s not just the grout lines where sealing is critical but the entire surface.
The first instance is when you have put white marble in your shower.
Shake a few drops of water on one of your tiles.
When should you seal marble shower tiles.
How to seal marble floors before grouting.
As polished marble has very little chance of water absorbency there is a much less chance of staining and therefore sealing is not really necessary.
Polished marble shouldn t need sealing before you apply.
Then wait 3 days minimum after grouting giving time for grout to cure and then seal the grout.
A major consideration when deciding whether or not to seal your marble shower is that hard water stains are a common theme in bathrooms specifically in showers and baths.
White marble including carrara and calcutta marbles often contain small deposits of iron.
Marble sometimes gets circulary etches scrathed into its polished face with sanded grout.
In addition if the marble is not absorbent then it will not absorb the sealer and the sealer wont work.
As polished marble has very little chance of water absorbency there is a much less chance of staining and therefore sealing is not really necessary.
Sealing marble or any other kind of natural stone tile is a very important and step that is often done at the wrong time or omitted altogether.