What Type of Grout Is Used on Tile Joints in a Shower?

If you are putting in a new shower, you probably long for easy answers about what products to use and what to avoid. You may have picked out some beautiful tile and wonder what type of grout to squeeze into the joints between the tile squares. Unfortunately, there is no one type of grout that works best for all shower-tile situations. So when you ask for the best type of grout for shower joints, the most accurate answer you can get is: It all depends.

Because the shower is one of the wettest spots in the house, that means that the material on the shower walls must be waterproof. Tiles are a very popular choice for shower walls and bathroom walls in general. They come in a range of options, from standard, economy ceramic squares to exquisite Italian-made tiles. But since multiple tiles are required to fill a wall, the spaces between the tiles must be sealed to make the wall covering waterproof. This is where waterproof grout comes in.

Grout is the product you use to fill the cracks between tiles, called joints. Sometimes you can squeeze it in like toothpaste, but in other cases, you might use special tools to get it into the right spots. The material you use to fill the area between tiles and tub or between tiles and shower drain is not grout but caulk. It too must be waterproof to prevent potential rot issues.

When it comes to choosing the best grout for your shower, the first choice is between sanded and unsanded grout. Note at the outset that this doesn't refer to whether you have to pass afterward with sandpaper. Rather, sand is a component of sanded grout, while unsanded grout – also called non-sanded grout – has no sand in it.

Basically, the choice will be made for you by the width of the grout lines between tiles. If those joints in your shower tile are bigger than 1/8-inch wide, you'll have to use sanded grout. Grout without sand in it shrinks as it dries. In larger joints, non-sanded grout shrinks enough to pull back from the tiles. It should only be used in small joints, those 1/8-inch wide or smaller.

But sanded versus unsanded grout is just one of your choices. You'll also have to decide between epoxy grout or cement grout. The traditional grout is cement-based, and it has been the default grout for years. It comes in both sanded and unsanded versions and is very affordable and easy to use. However, its surface chips, stains and molds easily, so you'll have to seal it after it has cured and dried completely.

Epoxy grout is the new kid on the block, made of epoxy resins and a filler powder. Very tough and durable, it doesn't stain or require sealing. It also dries much quicker than cement-based grout. The downside? It's quite pricey.

So now you've gotten the rundown on shower grout, but ultimately, for durability and moisture-resisting properties, epoxy grout is actually the best grout for your shower.