I work in a nursing home as the maintenance man. Our kitchen floor is red tile. It has grease in almost all the grout joints. We have floor drains in the floor. Will a pressure washer clean the grout and what will I have to do to regrout the tile. I have never regrouted before

Grouting is easy, as far as matching back up to a color, that will be tuff to do since there is grease and grim involved. I would guess a pressure washer would work just make sure the tip you use in a gerneral use tip, as for areas you need to regrout you may want to get a grout chart and go from there.

Ya it is easy, if you like crawling around on the floor, it is all of the prep that goes into it that can be some work. Floor grout is typically sanded and you will not be removing and regrouting (http://www.precisiongrout.com) it. If it is failing then you should contact a knowledgeable Tile contractor for some direction. Otherwise if you would like to give it a functioning uniform look then you can clean, stain and reseal the grout to a restored state. You might also consider contacting a contractor for this. Good Luck with your flooring...