Day 28: Pouring the first wall lift

Las Animas Concrete and Pacific Coast Concrete Pumping were back again today. This time concrete grout was pumped to fill the network of horizontal and vertical cells in the APEX blocks. The grout is inspected for slump to be sure it is not too thin or too thick. Here is a vid of Mark, the inspector from PSI, performing the slump test.

We passed with a slump of 8 inches, the thinnest mix allowed per structural engineering. A thin mix is desirable because it penetrates hard to reach areas more easily than a thick mix. Mark verified proper rebar placement before pumping. He also verified that grout filled the cells by poking a ¼” diameter rod through the APEX block skin at the bottom course. The rod came out wet with concrete indicating proper fill. Finally, Mark took samples of the grout which will be tested for compressive strength over the next several weeks.

Here is a pic of the pumping crew in action: from left to right, Trevor, Mark, Georg, Todd, Joshua & Justin.

The tasks were:

• Hold the hose over a cell with minimum grout spillage while concrete is shooting out at about 3 feet per second.
• Move the vertical rebars up and down in the cells to help consolidate the grout.
• Clean any excess grout off the top of the blocks.
• Center the vertical rebar in the cell after consolidation.
• Repeat for 100 cells.

Stapling plugs after filling cells under the window openings.


Marty strikes a pose in front of some extra grout used as fill against the east wall. This grout will help facilitate water drainage at this underground wall.

A beam support bracket set in place.

Rafael has a little fun while monitoring the hose.

We finished in just a few hours with no blowouts. We have the rest of the afternoon off, wohoo!

Pastel Green comment for today:
The Portland cement ingredient in concrete has high embodied energy which typically classifies a product as non-green. However, the APEX block cells minimize the amount of concrete needed to make an acceptable structure compared to a typical Insulated Concrete Form (ICF). Additionally, the house is expected to last hundreds of years making the use of concrete more tolerable from a life cycle analysis standpoint.

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Day 22: Pouring the concrete slab

I worked late yesterday (Tuesday) preparing for the slab pour, so I did not post. Some of the tasks completed Tuesday were:

• Completed routing of the remaining 4 PEX heating circuits.
• Pressurized the PEX heating tubing to 70 psi to identify a failure if one occurs before or during the pour
• Built wooden supports for the corners and window openings to prevent them from distorting outward when the concrete is poured
• Built a variety of wooden forms to create 1) a concrete curb detail around the shower, 2) notches in the door openings for the doors to seat into and 3) a depression for a tile mosaic art piece in front of the sliding glass door
• Photographed, measured and sketched all conduits and tubes that are under locations where fasteners may be anchored into the slab, i.e. interior walls and kitchen cabinets.

Here is a picture from the end of Tuesday.

On Wednesday, the slab was poured. The folks from Diamond D Concrete, Las Animas Concrete and Pacific Coast Concrete Pumping showed up early. Diamond D used a laser level to create a line around the inside of the home that represented the finish height of the slab. I am going to let pics and vids do most of the talking. In the following vid you can see concrete being pumped in the foreground and application of a rough screed in the background.

A perforated roller screed is then used to push down the larger aggregate and leave smooth textured concrete on top (called cream).

The cream surface is then finish screed by hand.

The surface is then rough troweled by hand.

A power screed is then run over the surface.

The guys then worked the surface further twice more with hand trowels to get the finish I desired – not too rough and not too smooth…just right. The guys really did a great job! All of the hard work and preparation from the past several weeks paid off. The day went by with few troubles. I’ll close with a pic from the East at the end of the day.

Green comment for today:
Consider concrete as your finished floor. Less material is required to stain the concrete than to cover it with carpeting or wood. The results of stained finish floors are limited only by your imagination - check out Diamond D's gallery.

Thanks for reading. Feel free to leave a comment.