UV unwrapping issue?

Hi all… I am fairly new to blender and have been modelling a house lately… Now as soon as I came to texturing I did select the cycles render, made a new material, added an image texture but the roof of the house is going nuts for some reason… The walls are perfectly fine though… Thing is I didn’t mark seam any of the walls… But the walls are working fine but the roof isnt… The “okay” textured part of the roof u see in the image was created accidently… I was getting freaky shapes in the UV/Image editor… so I just pressed W in the 3D mode and maybe clicked symmetrize or some other option and then clicked W in the UV editor image and BAM! Suddenly that part and its opposite similar one became perfectly fine… Now I am trying the same with the smaller roof parts(left and Right) but not getting the same result… Help please!!

You haven’t supplied a blend file so we cannot see what you see
The object has two materials, check that the face highlighted is using the correct material

Extremely sorry for that… I got frustated and deleted the whole file and now I am making it from scratch… Any tips for UV unwrapping??