How can I determine if I qualify for home office expenses?

Broadly speaking, I'm curious if I qualify for home expenses.  I work from home 50% of the time. 

 

In particular, I'm curious if this set of expenses qualify: My home office is in the basement. Flooding this year required me to (1) replace flooring in the room and (2) re-route water flow on my house to prevent future flooding. Would that qualify?