I am working on a house cake but I need help with how to do the roof. I am using the brick impression board for the sides but not sure what to do for the pattern of the shingle roof....

Any ideas?

What about overlapping circles cut with an icing tip?

For the roof on my haunted hosue cake I just cut a bunch of rectangles and layed them out in rows on the roof, starting from the bottom and working up so each one overlapped the other.
I cut them uneven on purpose so it looked like a old roof, you could use a cutter though for more even shingles.
Here's a pic.

http://www.cakecentral.com/modules.php?name=gallery&file=displayimage&pid=1497015&sub=1497016

I've seen Cake Boss and Courtney from Cake Nouveau use black fondant, spritzed with vodka and then poppy seeds applied to it...It looked like a tar type roof - pretty easy.