Day 27: Preparing for a lift

Today we prepared the walls for the first grout lift. Grout fills the interconnected horizontal and vertical network of cells inside the APEX blocks creating the building structure once the concrete is cured. A lift is the height the grout will be poured at one time. In this case, the lift is 5 courses (approximately 80 ionches). The grout is a thin concrete mix and can leak out through holes and gaps in the walls and bucks. The grout applies hydrostatic pressure on the walls and bucks. This pressure increases towards the bottom of the wall just as water pressure against your body increases the deeper you dive. Corners and thin areas of APEX block are most vulnerable to a phenomenon called blowout – when the grout fractures a portion of the wall material and begins gushing from the opening. We want to do everything we can to avoid blowouts. Some of the things that were completed today:

• Plumbing vents and drains that penetrated partially into APEX grout cells were surrounded with foam, sealed and supported so that grout would not leak and the plumbing would be accessible in the future.
• Small wooden forms were installed to properly locate 2 beam support brackets that must be cast into the grout during this lift.
• Threaded rods were cut and placed into the window and door buck holes drilled yesterday.
• Walls were shored up after ensuring they were vertical.
• Made a final check to ensure window and door bucks were level and located properly in the openings.
• All 6 exterior corners were shored up with a frame after ensuring that the walls were vertical.
  
• Holes were drilled through the exterior 2 inch thick skin of APEX block under window openings to provide access for the concrete pump hose. All wall cells will be filled from the top of the 5th course of block, but these additional holes will ensure that grout is placed under the window openings.
  
• Gaps around door and window openings and any gaps in the APEX block wall larger than about ¼ inch were filled with closed cell spray foam insulation. This material expands several times its size after being sprayed from the canister and fills the gap to prevent grout leaks.

Following are a couple pics from the end of day 27.


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