I pressure wash driveways and sidewalks every once in a while for some money on the side. Got an email today, this guy is buying a warehouse soon(15,000 sq ft!!) and wants the floors (And I have no idea what material the floor is at this point BTW) "washed with a very light acid solution to prepare fror seal coating the concrete". Also there is no running water in the building. So that means If I decide to take this job I would have to rent a tank but from what I understand their usually 500 gallon capacity which means PLENTY of stopping for refills I'm sure. The main thing I'm wanting to know is what chemicals/mixture should I use for this. I started talking with a local pressure washer dealer in my area and he was starting to tell me that I might not even have to use a pressure washer at all, just dilute acid and spread it around the floors. Any help would be appreciated and no, it's obvious I'm no professional so theres no need to remind me that, convince me not to take this job up or whatever, This is not a good month for me financially wise and I sure can use some extra cash. Don't think I want to pass this one up And how can I forget, what would some of you charge for a job like this. I know some companies have a square foot rate. I have an idea of the cost for the tank rental and even an extra machine or 2. So I would really need to know the labor charge and chemicals once I find out the proper kind to use. Any help would be greatly appreciated.