Managed to spray the roof of my SF house as well as prime the door and some of the windows:
I used Tamiya's Linoleum Deck Brown Spray Paint for this. Their spray paint is specifically for plastic so I had no problems with flaking. The paint goes on really well and dries pretty quick. I could apply a second coat after about 30 minutes. It also has a very nice matt finish, unlike other spray paints which often give this semi-glossy look.
Sadly, I got alot of paint on the walls this time :(
I tried using Mr Color Thinner to remove the excess paint but it could only remove some parts of it. One of the walls is badly stained because I didn't fully cover that area with some paper / tape. Silly me. I thought the paint wouldn't be able to get on there but I was wrong:
I had plan to leave the walls in it's original color because I couldn't find a nice shade of yellow to match the roof. But that's alright, I guess I'll just have to pick a color for the walls now :)