Face missing when importing from blender, nothing is working.

I created this house model in blender, but my problem is the back side of the roof will not render. I have tried ticking backface culling, recalculating, flipping normals everything. Nothing will work, i import it into unity and it just refuses to show up.

You probably need to “Recalcualte normals” in blender in “Edit Mode” under “Shading / UVs” there is a button called “Recalculate” under the “Normals:” section. Select all vertices and press that button.