Seal the natural stone prior to grouting. If working with a small area a paint brush can be used to apply the sealer, and if the installation area is larger a hand-held sprayer such as those used to spray for weeds in a garden can be used to apply the sealer. In both cases, follow the manufacturer's instructions on the container of sealant for instructions on how long to allow for drying before moving on to the actual grouting process. Allow to dry completely before grouting.
Force the grout into the joints between the natural stone tiles with grout float. If working with polished marble or granite, the grout can be spread across the face of the title from joint to joint because the grout will not stick to a polished surface. If working with a rough natural stone such as slate, tumbled marble or travertine you will need to avoid spreading excess grout on the surface of the tiles themselves as the natural crags and valleys can make for difficult cleaning.
Allow 15 to 20 minutes for the grout to dry in the joint before washing. Test if the grout is ready to be cleaned by gently probing the surface of the grout joint with your finger. If the grout is tacky and sticks to your finger it needs to dry for another few minutes; otherwise it is ready to be cleaned.
Fill the bucket with water and dampen the sponge slightly. Use the sponge to smooth the grout across the grout joint with small, circular motions, rinsing the sponge frequently in the bucket of water. Once the majority of the grout has been cleaned from the surface of the titles and the joints smoothed over, allow for an additional drying period of 15 to 20 minutes before removing the final haze of grout with the sponge.
Allow to dry for a minimum of 72 hours before sealing.
Check the surface of the natural stone for any grout haze that may remain. Use water and a sponge to completely clean the surface if there is any haze left, allowing the surface to dry completely before sealing.
Apply sealer in small areas with a paint brush, or a sprayer for large areas. Follow the manufacturer's instructions in regards to how many coats of sealer are required for different types of natural stone. Allow a minimum drying time of 24 hours before allowing foot traffic or moisture in the case of showers or wet areas.
Things You Will Need
- Grout float
- Latex-modified grout
- Bucket (3 gallon or larger)
- Tile sponge
- Paint brush
- Sprayer (optional)
- Certain types of natural stone such as travertine or tumbled marble have natural holes and pits which can either be filled with grout or left open, depending on personal preference.
- Natural stones readily absorb moisture, so do not worry about getting excess sealant on the face of the tiles themselves, or the grout joints.
- All materials and tools can be purchased or rented from your local home improvement store.