The most direct route for pumping deck concrete was through the lobby of Metropolitan Square, a 42-story St. Louis office building. But the lobby's 50-foot high ceilings, Italian marble walls and floors, and upscale retail arcade made it off limits to the concrete contractor. To bypass the lobby, the contractor had to make a 90 degree turn with the pumpline and drop the line elevation 18 inches to pass under a loading dock. After another 90 degree turn the line went vertical with a third 90 degree elbow. The ready mix producer took several steps to improve pumpability. The most important was using vacuum-saturated lightweight aggregate. To strike off the concrete, finishers used a 16-foot floater screed with vibrators run by compressed air. The air screed helped finishers produce flatter floors and also increased production.