Tailed Textures for Game

I’m going crazy for understand how to export a Model with Tiled Textures (rooftop).
I made a low poly House and textured the rooftop.
I also baked Ambient Occlusion.
Now I can export in fbx for Unity3d, but how should I manage the roof’s Texture?
I figure out that I’ll face the same problem for floor’s texture.

Please Help