The manufacturer recommendations should guide you, but with the products I've tested, I'd look at 24 ounces per piece, the bottom one representing about the same as "two pieces", so 48 ounces total on that one.
That will create a great deal of fumes, and potential health and fire hazards. I would make sure you have a great deal of ventilation, respiratory protection, and the customer out of the house.
Nevada customers should remain out of the house until the odor dissipates, California customers a week, and only after a dozen governmental agencies and a Wiccan priestess guarantees that the home is free of all toxins real and imagined.