Even if the grout is sealed, the tenants do not care enough to clean the mess in a timely manner, the stuff in it will stain the grout and with the chemicals and pressure wash the seal will fade/go away.  

There is always someone who will dump chemicals all over the place and call it a treatment, sometimes this works.

If you get out towards Pasadena area, it’s all oil refineries and chemical plants.

If the place is empty, it is probably easier for them and they can use different chemicals then if it has people's belongings in it. 

Kitchen coming out next week.There is a lingering odor that will not go away, not chemical, feline or decomping rodents.

@Steven MaldonadoDefinitely pay the professional Reglazer with the harsh chemicals instead of the kit from the Home Depot.

Response to a persons question on Crime management at Self StorageMy Brother wrote the Nuclear, Biological and Chemical warfare manuals for all North American Air Force and Army bases.

Older elderly retired, but is not the cleanest person, my pest control guy went over there and said there where bunch of fruit flys and tenant wanted him to spray chemicals which he said he couldn’t do that, and kindly said to clean up and pick up after her self.

Nefarious folks may try dumping oil, chemicals, etc. on your land and contaminate the soil.

I made the move from chemical engineering to loan origination part time initially and eventually fulltime and wish I would have done so sooner.