warp and deform - maybe permanently though not always - unless you support it carefully. This may, or may not be important to you. It will still float. But it may not perform 100% up to snuff if it deforms. My suggestion is to devise a rack of some kind so that the weight of the hull is supported in the area of the bulkheads if it has bulkheads, either on its side ala J cradles, or on the deck, not the bottom. Use a cockpit cover or canoe bag to keep critters etc. out of the inside of the hull.
Cartop Kayak Carriers
Touring Kayak Paddles