Why isn't "the roof" accepted?
The roof is "o telhado".
Not in PT-PT though?
Actually, in PT-PT, «telhado» = "roof" too, because that's what you cover with «telha» = "tile."
We're learning BR-PT though.
Yes it is. A ceiling is inside and a roof is outside anyway!
I translated it as "teto" (roof, instead of ceiling) and DL said it was correct.