Every other year is best to prevent cracks from starting & expanding!
For residential, we recommend staying off newly sealed asphalt for 12 - 24 hours, weather dependent. For commercial, sealing can be done in sections to keep business running as usual.
If you don't seal your grout, it will absorb water, bacteria, and stains. Adding a grout sealer protects your grout so that it's waterproof and will repel moisture and germs. Sealing the grout helps prolong the look, texture and consistency of your grout and it prevents mildew and mold.