Yes, it is important to reseal the grout after steam cleaning. Sealing grout helps protect it from dirt, mold, bacteria, and mildew. If you don’t seal the grout lines, these contaminants may become trapped in the porous surface and cause discoloration or deterioration of your beautiful tile flooring or wall tiles. Sealing also prevents water from seeping into the tile substrate beneath your tiles - this can cause significant damage if not addressed properly over time. Depending on where the tile is located (in a bathroom shower stall or around a pool) and how often you steam clean that area will determine whether or not you need to reseal your grout more frequently than other areas of your home with less wear and tear from moisture.