Once the hub of Houston's U.S. mail system, the 1930's era Post Office fell into a state of abandonment and neglect. That changed when efforts surged to transform this 16-acre site into a mixed-use complex expanding Houston’s vibrant downtown scene. Post HTX is the largest urban farm in Texas and Hydrotech is proud that Monolithic Membrane 6125 and our full Garden Roof Assembly is protecting this incredible building.