Concrete & Steel Stairs


Early in our Studio 804 design process, we realized that there would need to be a second level to contain the amount of space required by the program at hand.  A fellow Studio 804 classmate, Owen Huisenga, and I began experimenting with stair designs.

We quickly moved toward cast concrete stair treads, as the raw nature of concrete fit well into the material language of steel and glass that was developing throughout the rest of the building design.  We began building melamine forms to cast what would be many prototypes over the course of a few months to test size, strength, color, finish and cure time.  Ultimately, we settled on 36”x12”x2.5” tread and used a charcoal color concrete dye to create a balanced contrast between the treads and the painted steel stringers.

Each stringer was constructed with 3”x12” steel c-channel with 12” sections of steel angle welded to the channel to support each tread.  Since each stringer weighed approximately 400 lbs, we used a block and tackle to raise them into place.  Once the concrete treads cured, we drilled holes and, using epoxy, set all-thread to use as a means to bolt the treads to the stringers.

To continue the design aesthetic and to simplify the fabrication process, we used the same stringer construction for the two runs of exterior stairs in “pod 3,” the outdoor mechanical yard.  Because concrete stair treads would become hazardous after a rainstorm, we changed the tread construction to galvanized bar-grating to match the construction of the pod 3 top floor deck.


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