Iowa Code § 359A.19: Duty to maintain tight fences.

All partition fences may be made tight by the party desiring it, and when that party’s portion is so completed, and securely fastened to good substantial posts, set firmly in the ground, not more than twenty feet apart, the adjoining property owner shall construct the adjoining owner’s portion of the adjoining fence, in a lawful tight manner, same to be securely fastened to good substantial posts, set firmly in the ground, not more than twenty feet apart.