Outdoor Mural Wallpaper Installation

[sno]

I have a 13'x9' outdoor stucco wall that is blank, so I want to put up an 8 panel, 12'6"x9' mural of a beach/sunset. I live in a condo and the wall is mine, but I still want to be as minimally invasive as possible. I am also trying to do this all for under $200, and the wallpaper is costing $80.
My best idea is to screw 2x4s vertically to the stucco (into studs), and then attach sheets of hardboard/masonite to the 2x4s using liquid nails or maybe some very flat headed screw (since the hardboard is so thin, I figure it will be next to impossible to countersink any screw). I would then apply the wallpaper using normal paste, and cover the wallpaper with clear contact paper to protect it from the elements.
Any ideas on whether hardboard is the right wood to use? Which side of the hardboard should I apply the wallpaper to? I figure the smooth side is the best for applying wallpaper to, but the smooth side also seems like the most weather resistant, so I would want that facing the wall since the contact paper will be protecting the other side. How weather resistant is hardboard? Should I paint it first?
How would you complete this project?

[Tom Miller]

I'm no stucco expert, but my inclination is to avoid putting holes in the stuff.

Is there anything overhead (e.g. the eave) from which you could hang this panel? If so, I'd construct a large frame and lattice with 2x4s, and attach the sheet stock to that. But, I'd make it 12' x 8' so I'd only have 2 seams.

A single 8' - 10' long 2x4 attached to the eave, with 1/8" cable running down to the frame would hold it.

Regards,
Tom

[crokett]

If you are talking about the brown stuff, then hardboard isn't weather resistant at all. Panting it will only delay the crumbling once it gets wet. What I would do is look for either MDO or a sign maker's plywood. Sign maker's ply has a covering on both sides that makes it smooth and last a lot longer.