Back up before Free Space Wipe

Have been using CC for some time and never had courage to try Free Space Wipe until now.

Is it safe to do Wipe for free space and should I back my drive before doing so.??

It's always wise to backup especially if you don't trust using something first. While I don't think the Wipe Free Space would destroy your hard disk if you rarely if ever use it, however obsessive repeated usage of it increases the possibility of a hard disk failure.