Thanks for that,
I think some UV generation happened on import, because I’m seeing a different UV layout than the one in your screenshot above.
Try importing the .fbx that you exported and run through my steps again. (Running AutoUV or Unwrap function on your existing mesh before trying with the import could be worth a shot)
If that still doesn’t work out - this is your roof that I rotated the UVs on.
Roof_RotatedUVs.FBX (20.8 KB)
Moving forward: You can control the “size” of the roof tiles by either re-sizing the UV island or using a ‘TextureCoordinate’ material node (U/V Tiling in advanced settings on this node, feed it into the 'UVs" of your Texture Sample node)