The Extra Space Storage, located in SE Portland, is a five-level interior storage facility. The 28” mat slab foundation with a 40” thickened edge, was made up of 1,400 cubic yards of concrete. The foundation also included a 60” crane foundation at the bottom of the elevator pit. To support the compounding load of the five-story structure, the first three levels were constructed under compression as post-tension concrete slabs. Designed to be lighter and stronger than most conventional slabs and with flexible reinforcement, the two top levels consisted of slab on metal deck.
The mat slab foundation included over 500 linear feet of steps to create various elevations throughout the main floor of the storage facility. The large steps varied in height, where the largest elevation differentiator was 30 inches. Because some of the slab would be exposed in the final product, much of the mat slab required a hard trowel finish.
To support the three levels of PT decks, 176 concrete columns were cast in place. The finished facility feature exposed concrete columns. The storage facility was completed on schedule and within budget, exceeding owner’s quality expectations.