I guess, as Stephen said, it depends.

I have also seen sandbox roofs that can lower down to keep out critters,
cats especially, when not in use. That would be a lot of roof to lower and
raise. If they can do it here
http://rogerscentre.com/aboutrogerscentre/funfacts/ surely you could do a
12x10 raising and lowering roof! Think monster house. 4 steel guide posts,
anchored in concrete. Cables, motor, pulley, safety setup like garage door
opener has. In fact, you could probably cannibalize a couple of garage door
openers to do this. I guess I way off track. Anyway, have fun and be safe.

"donald" wrote in message
...
I am going to build a roof over an existing sandbox which is 12'x10'. How
many posts will be required for construction? I was thinking three posts on
the long end and two on the short end. Is this sufficient or could I
actually get by with four?

Thanks in advance.