Why not treated lumber?Original owner enclosed an outdoor porch. They put wall bottom plate directly on porch slab then built up interior slab by 1/5 inches so it is level with house slab. Of course bottom plate is rotting out and I need to replace. Soooo, I need to extend the interior slab out about 5 inches to support a new bottom plate, but it will only be about 1.5 inches thick. What is a good way to do this? With it only being 1.5 inches thick can I even drill and put in rebar to existing slab? Not sure if drill is too wide to directly drill into existing slab without going in at a good angle.