Spanned concrete strength and support deflection

Question:

I have a stamped concrete porch that spans approximately 12' by 40'. The concrete was poured on metal decking with 4" angle irons supporting the decking every 2'- 0". During the pouring of the concrete the supports underneath demonstrated deflection from the weight of the concrete. Now 8 years later, the top of the porch is still level and has no cracks or humps. I am selling the house and the potential buyers are saying the supports showing deflection are structural deficiencies. Is this a problem?
Answer:
It is very common during pouring concrete that everyone's attention is focused mainly on leveling the concrete not knowing what happens at supports below.

Metal decking is weakest when they are only supported at both ends which is most likely the case based in your explanation. Had you built a temporary wall at mid-span of the deck, it would have had strengthened the deck and would had eliminated the deflection problem.

Structurally if it was engineered properly from the beginning the structure should be fine. Personally I would build a stud wall at areas where the deflection took place. The wall will serve two purposes 1. add extra support to the metal 2. it will cover-up the deformation which to an uninform buyer will be a red flag