Clearly this isn't his first rodeo.
Construction Worker Casually Tosses Cement Onto High Wall Like A Total Pro

This is a video of a construction worker applying cement to a wall too high to reach by hand by just tossing it up there. His aim is impeccable, and if there was a basketball game he wouldn’t have missed a single shot. Still, as impressive as his technique is, I still can’t help but feel that a ladder was the correct answer here.