Why isn't there a roomba-like deck painting robot for sale or rent?

[nyone]

Decks shouldnt be painted..thus the need to repaint, scrape or sand them every few years.

Oil based stain however is way easier prep.

 

[oosik]

Full load of paint and white hot batteries. Are you going to like the pattern this little thing does on your asphalt driveway - as it goes on it's merry way. You know it will jump off the deck - first chance it gets.