Carrara Marble Sealing Before Grouting

If these deposits are close enough to the surface they can be oxidized by water absorbed during a shower creating a rust stains.

Carrara marble sealing before grouting.

Sealing before grouting is smart when using a dark grout color with light colored marble tile. Now if your grout is a dark color then it can be advantageous to apply a sealer before grouting to keep the grout color from absorbing into the edges and discoloring the marble. I used this sealer and just put it in a spray bottle and sprayed three coats on the ungrouted tile. I just installed marble tile in an entryway dark green with dark grout.

You ll have to replace those to make it look even. Because marble is a natural stone and will absorb color you need to seal them before you grout to prevent the grout from discoloring the tile. I have always sealed after but i have also done very little work with marble tiles esp dark colors esp on a floor. He says it s not necessary to seal the tiles before grouting and that he s done it many times without problems he has 25 yrs experience in stone work however you have previously recommended to me that the tiles be sealed.

Carrara marble needs sealed. Those couple of tiles must have been a bit more porous than the rest. Then i used a grouting sponge to wipe off any excess. The edges of the tile are much more absorbent and if the grout color is dark then the dark water from the grout will absorb into the edges of the tile and create a picture frame stain.

My guess is it wasn t sealed so a couple tiles soaked in some grout darkening them.