Hello, My 408 sq ft enclosed patio has a flat concrete roof/deck that water ponds up on and has at least 2 large cracks, which leak into the patio below. The roof/deck appears to be a solid concrete slab, no attic with some kind of coating over it. The soffits are cracked and there is exposed & rusted re-bar showing. The roof/deck also has a wooden railing system, which is failing & needs to be removed/replaced BUT it is attached directly right into the roof/deck. What's the best way to repair? Thanks!