Grouting Porous Tile

One of the things that the homeowner loved about the tile I used for the backsplash (see this post) was the look of the porous tumbled marble. Most of the tiles were very textured, with some having decent sized impressions and holes in them. It's always recommended that you seal the tiles before grouting to help keep the grout out of the tile, however, with porous stone, the grout will still fill all those voids. So there are a couple of ways you can approach grouting these tiles.

ONE WAY- FILL THE HOLES

Probably the most common way is to just grout it all and fill the holes. They will still have the character of the porous stone, but the deeper pores will be mostly filled with grout. This is usually the best method because if you don't fill the pores, they will eventually get dirt in them or even food particles if it's around the countertop. These will be a major headache to try to clean later if they aren't grouted.

If you're filling the pores with grout, I'd suggest using a grout color that matches the stone. If you use a highly contrasting grout color, the filled pores may not look as natural.

ANOTHER WAY- DON'T FILL THE HOLES

Okay, you probably aren't going to be able to keep grout out of all the pores, however, you can use painter's tape to cover the faces of the tile if you want to keep the grout out. If you've got the desire and the time, you could actually tape the face of every tile.

I used this method with the backsplash to cover the pores on just a select few tiles that had the most character, trying to have some consistency throughout the backsplash. I used some larger blue painter's tape and cut it with scissors (rather than tearing it). This makes a clean cut that lays flatter against the stone making it easier to grout over.

After taping the stones I wanted to preserve, I grouted as normal right over the tops. I removed the tape after I had already sponged off the grout a couple times. The tape worked great and the homeowner loved the texture that it left in the tumbled marble.

Of course, when you're finished it needs to be sealed again, this time focusing on sealing the grout.

-Peter

www.CarpentryGuy.com