Abstract: A grate hatch and folding barrier assembly has a pair of doors that open in a cabinet-style manner and lie flat or generally flat atop a support structure within which the grate hatch and folding barrier assembly is installed. A folding barrier gate assembly may be deployed from a collapsed position to complete a four-sided barrier around the hatch or opening. The folded barrier gate assembly has two opposing barrier gates, and a pair of secondary barrier gates that connect with and extend between the two opposing barrier gates to form the four-sided barrier around the hatch opening when fully deployed. When the barrier is no longer needed, the barrier assembly may be folded or collapsed and stored in the opening beneath or below the doors and the doors may then be closed.