Years ago, it was quite common to make machine shop floors out of 4X4 or 6X6 about 6 to 10 inches long standing on end tightly together. In the machine shop, where cutting oils are used all the time, any spilled on the floor would be absorbed and essentially disappear. The floors were amazingly solid and at the time I guess very low in cost. Your question just brought that to mind. As to your question, there's no reason that a 3/4 inch floor setting on supported stationary timbers 8" apart wouldn't hold anything you would want to put on it! I wouldn't go beyond 10" apart though and use a quality grade of plywood, no sheathing! JMHO. PJ