Your understanding of structural theory is a little way off, Concrete withstand compressive strength while steel rebar withstand tensile strength. Together the two material used together is called Reinforced Concrete. The steel rebar helps resist bending (moment) and tensile actions/force acted upon the component (beam, column and slab), but concrete is the one holding everything together.

how long is the period for latent defect?

Ok, i have to admit i don't really understand what is latent defect.

Altho google explains it is " a fault in the property that could not have been discovered by a reasonably thorough inspection before the sale."

It didn't really explain its relation compare to DLP. And the only thing that come into my mind is.. does it only apply to sub-sale or "build and sell" type property where the property is already completed?
(Correct me if i am wrong as i am here just to learn more.)

Maybe "life's not fair" should share a bit more details?