Grouting is the step most people rush, and the reason a lot of tile jobs look worse than they should. The tile sets the structure; the grout sets the look. Here is how to do it right.
Choosing Grout
There are two main grout types for most residential tile projects: sanded and unsanded.
Sanded grout is used for joints wider than 1/8 inch. The sand provides body and reduces shrinkage. Use it for floor tile with standard spacing, wall tile with wider joints, and any joint over 1/8 inch.
Unsanded grout is used for joints 1/8 inch and smaller. It is smoother and works better for polished stone where sand can scratch the surface. Most modern rectified porcelain with tight joints uses unsanded grout.
Epoxy grout is a third option. It is extremely durable, stain-resistant, and does not require sealing. It is also harder to work with, more expensive, and less forgiving if you are not moving quickly. We use it on commercial applications and on projects where the client wants a truly maintenance-free grout joint.
Mixing Grout
Follow the manufacturer's water ratio. Too much water weakens the grout and causes it to shrink. Mix to a peanut butter consistency, let it slake for the specified time, and mix again before use.
Applying Grout
Work in manageable sections, typically 10 to 15 square feet at a time on walls, slightly larger on floors. Apply with a rubber float held at a 45-degree angle, working diagonally across the joints to pack the grout in. Work in multiple directions to ensure the joints are fully filled.
Do not let grout sit too long before cleaning. In Central Florida's heat, grout skins over faster than you expect.
Cleaning and Haze Removal
After packing the joints, use a damp sponge to remove excess grout from the tile surface. Work in circular motions and rinse the sponge frequently. Do not use too much water. Excess water pulls the grout out of the joints.
Allow the joints to firm up, then come back with a clean, barely damp sponge to remove the haze. A second pass with a dry microfiber cloth will take care of what remains. If the haze has dried and hardened, use a grout haze remover per the product instructions.
Sealing
Cement-based grout should be sealed after it has cured fully, typically 72 hours. Apply penetrating sealer per the product instructions. Natural stone tile should also be sealed before grouting to prevent the grout from staining the stone face.