floor
floor
floor!
As the roof is the top of the building, it follows that the floor would be the opposite, as it is the bottom of the building.
An opposite of the word "to" is from.
The opposite of up is down. So, opposite of the opposite of up is up itself.
floor
floor!
The opposite would be the building foundation, or the basement floor. (Most thesauruses simply say floor.)
floor
ceiling
The opposite of bottom would be the top, so the oceans surface is the opposite of the ocean floor/bottom.
Depending on how you look at it, the opposite could either be "bare floor" or "ceiling tile".
The ocean's surface
As the roof is the top of the building, it follows that the floor would be the opposite, as it is the bottom of the building.
You push against the floor; the floor pushes against you - in the opposite direction.
divergent
true