Once steel reinforced concrete footings were installed around the perimeter of the new sanctuary, attention turned to building wooden forms that serve as a mold into which concrete is poured to create foundation walls. The wooden form, comprised of an inside wall and an outside wall, are sandwiched around a lattice or grid of steel rebar (stout 5/8″ steel rods).
The wooden forms, preassembled off-site and delivered to Redeemer on large trucks, are large wooden frames themselves reinforced with steel plates. The side of the form that faces the foundation wall is a smooth treated board that will not stick to the poured concrete. A crane was delivered to the construction site to lift the heavy wooden forms and rebar lattice into place.
Inside this sandwich of wooden forms is a lattice of vertical and horizontal steel rebar that will be surrounded by the poured concrete. Iron workers (rod busters) cut and assemble the rebar lattice onsite, which is anchored to the concrete footings by a tie to the “L” bars that were previously placed in the concrete footings.
The foundation walls are nearly fourteen feet tall, so a railed walkway lines the top of the wall so that workers can traverse along the wall to connect the various forms and eventually pour and level the concrete. The top of the wall is particularly intricate as both sides of the wall require notches and slopes to hold the exterior brick and interior planks that comprise the new sanctuary floor. The wall itself is 20″-24″ thick.
Work began on the west wall of the sanctuary and proceeded around the southwest corner of the sanctuary to the front (south) of the new church. This west wall and southwest corner was the first section to be completed.
Concrete was poured in this section first in a single, nearly three hour, continuous pour. The same pumping truck that poured the anchor pads and footings was used to pour the foundation walls. A continuous string of trucks arrived on a carefully orchestrated schedule to assure that wet concrete would always be available throughout the three passes that were necessary to fill the forms.
After a day or two the wooden forms as then carefully removed from the now hardened walls. The walls will take weeks to cure 100%, but are “solid” in 24 hours. Quality engineers are on site taking concrete samples throughout the pour to assure strict quality standards are met. While the wooden forms are removed from the west wall, work has continued around the south and east walls to form the rebar lattice and eventually the completed wooden forms. A transit is used throughout the process to assure that the walls are in the exact location required.
Preassembled wooden forms arrive on site to build the foundation walls.
Workers build a railed walkway at the top of the foundation forms.
The inside wall and steel rebar is in place. The outside form comes next.
Steel brackets and planks form the walkway high above the basement floor.
A large crane swings the wooden forms and steel rebar into place.
Rodbusters tie and crimp the steel lattice to form a solid cage.
Drone footage shows the crane just outside the newly formed west wall.
The rebar cage can be seen wedged between the two wooden form walls.
The pump truck begins the first of several passes to fill the form with concrete.
A final pass tops off the foundation wall. More steel is inserted to connect with the wall above.
Two and sometimes three mixer trucks were available to feed the pumper truck.
The wooden forms are carefully removed revealing the newly poured concrete wall.