Concrete sand vs. Mortar sand for top footing Nov. 12, 2010, 09:39 AM ... (I would imagine that concrete sand is finer and that mortar sand is coarser but still with the fines?)....sorry I can't be of help there. ... It is heavier than the red 'bank' sand that is most common around here and will not wash or blow away as easily. And has a nice ...