Princeton Friends School Annex: Concrete Block Step Down Footing

The beginning of the block work for the foundation walls began today. First though, the wooden forms needed to be stripped off of the concrete footings (photo 2).

To ensure that the footings were level, the corners square and the footprint of the building accurate, the footings were surveyed and the corners of the footings were pinned with steel markers. These markers created accurate points of reference for the block masons to lay out
their walls (photo 1).

Because of the change in elevation at the site, the footings at the west wall needed to be stepped down so that they would remain below the frost line. However, the concrete floor of the bottom level of the Annex will be poured to a height 4" above the top of the upper footings.
Therefore, this stepped down portion of the west footings needed to be raised up to the height of the rest of the footings. This was achieved by the installation of this portion of the block wall today (photos 3, 4, and 5).

Tomorrow, the block that was laid today will be grouted solid with concrete. This concrete will fill the hollow cores of the block while also surrounding the steel reinforcing bars which had been embedded into the concrete footings last Friday. This grouting will turn the hollow core blocks into a solid wall anchored to the footings by the steel re-bar. ~ DS