Well, I'm a newbie too, compared to some experts you can find in this site.

For the tiles: I modeled one tile from a polycube, then I bent it using a bend deformer. Then I duplicated it 20 times to make a row, with a small translation value. I grouped that row and duplicated it 30 times (or so) to make a big area (20x50 tiles). I grouped and rotated all that 180° in order to obtain the lower tiles. I repeated the whole process 4 times. At last I moved some individual tiles a little, or even deleted them. You don't want a "perfect" roof. A really important think, once you are done: COMBINE all the tiles. I didn't do that at the first place and I finished with more than 1000 individual tiles (even if they where grouped). If you don't combine the tiles in 1 or 2 objects, Maya will get really slow.

Here is an image of a single tile: