We used the same lumber and support set-up as the previous slab pour. Our forest of small tree trunks were re-used from the last pour. They look like they are growing from the floor to the ceiling holding up the forms that would eventually become the living room ceiling and floor for the second and third bedrooms. You can get a better look from the photos below how the steel, styrofoam and wood structure is put together. Once the cement was poured and hard enough to step on they began raising the walls, installing the rough-in electrical and plumbing for the second and third bedrooms. The support below the slab will stay in place until the cement cures which will probably take about a month.