I planned to use Restore deck coating for the exterior finish. It's waterproof and has a similar texture to truck bed liner, has a 10 year guarantee and comes in many colors. I like the idea that it will look a lot like Stucco. In Mexico, everything is built out of cement, so the perception is that cement is more secure. Plus, esthetically I have the feeling it will look really nice.
However, I recently found out that Restore doesn't work on vertical applications. Apparently it runs off. Bummer! After hours of research I haven't been able to find a suitable substitute. It only comes in 2 and 5 gallons so today I bought a couple gallons and will give it a try and see what happens. Maybe I can figure out a work-a-round? If it doesn't work maybe HD will be kind enough to give me a refund?
$39.00 for 2 gallons and a special roller.
The other option is this Ames Block & Wall liquid rubber. It goes on like paint, but it's 3x thicker and forms a completely waterproof barrier. Most of the other similar products can't be used on wood but this can. It can also be color tinted. The only downside is that it's not textured.
$159.00 - 10% Ace discount and shipped to my local Ace store for free = $148.17 total.
Which is where this stuff comes in. It's an exterior texture additive. You just mix it into the paint and roll it on. I called Ames and asked if it would degrade the quality of the waterproof coating but all they said was "I don't think so". I'll try the Restore deck stuff first. If it doesn't work the Ames Block & Wall will be the slightly more expensive plan B.
Around $2.50 per gallon + shipping.
Here's a really simple illustration to show what I have in mind for the exterior.