Can't build floors in certain rooms in Sims Mobile

Hi ..I'm new to sims4..I hope you figured it out, and I was hoping you can answer a question for me.

How do I recover the floor after accidentally deleting it? 

I didnt noticed I had till well after I had drawn a bunch of stuff so I didnt know how far back I deleted the floors and didnt want to back track and lose everything else...please help

Thanks

Hi,

I've done the same thing before.

Just rebox the room with new walls, you might lose windows and some other stuff but you'll get your floors back