About this image

This is the roof material I've been using on my Cheydinhal house models.  I can't really tell if it's good or not so I'd appreciate some thoughts on it.  I made the textures from renders of 3d models I made in blender and then edited in Gimp.  The material feels a little flat but the normal looks pretty ok in my opinion.   Overall, I don't really know what I'm doing when it comes to making textures, so I'd really appreciate some help on this.  Thank you. :)