Castro Valley is unincorporated, so building permits here come from Alameda County. Owners apply and schedule inspections through the Alameda County Permit Portal. Whether your project needs one depends on the work, so I'll tell you at the estimate, and if it does, we'll file it with the county for you or walk you through it if you'd rather file it yourself.
The coating itself is regulated too. The Bay Area Air Quality Management District doesn't allow coatings to be applied in the Bay Area when their VOC content, the solvents that evaporate as a coating cures, is above its limits. It's fair to ask any contractor whether the system they're proposing meets those limits, and we'll answer that for the system in your estimate.
We're based in Castro Valley and do the same work for shops and businesses in Hayward and San Leandro, along with Oakland, Dublin, Pleasanton and many other cities around it. The questions are the same everywhere we go, namely how the floor is used, how long you can close and what the slab is hiding.