If you have a fence in the yard, you could make some right angle brackets or buy them for that matter, and store it on the fence. By draping a tarp or some such from the top of the fence, it would be easy to keep the tarp from touching the kayak and nothing will build up on it. Mount the brackets to the posts though.

Or you could use hooks and motorcycle straps to store it the same way.

Or you could buy a kayak stacker, which is two long web straps with web loops that slip over the kayak and paddles. This would store a combination of five or more kayaks and paddles (if you double up on the paddles.). It can be used hanging from the ceiling or from a wall or fence.

Kayaks are fun, but storage is a problem! I have three in my garage plus the one I am trying to build!! I live in a townhouse complex and don't feel comfortable leaving the boats outside. Plus the landlord doesn't even like my old van in the parking lot so I'm sure she won't like three kayaks on the fence.

Oh well, hope this helps. Ian