The Concrete Stem Wall

. Here's a closeup of the dry stacked stem wall:

The bottom row is half-backfilled with gravel, both inside the barn and out.

Once the entire perimeter of the wall is in, I'm ready to lock it in place.

I've ordered enough 10' lengths of rebar to put rod in every void. I'm going with the 3/8", so that I can easily cut it all with 24" bolt cutters ($40). I've also ordered purified sand, and many bags of cement, to make concrete. But I've first got to use up the dozen Quickcrete bags, before I move on to making my own.

I cut the rod 12" longer than the height of the stem wall, so I can pound it down and through the rubble trench. I pound it in with my 2lb sledge. Sometimes I hit rock and cannot go any further with the rod. Then I go to a shorter piece. But most I'm able to pound through.

Mixing the Quickcrete is easy. You empty the bag in the black plastic tub and add water. I mix it up with a garden hoe - a mason's hoe is ideal, with a hole in it, for stirring, but I'm trying to find some purpose for the tools I've got, since my hoe so far has been useless for hoeing.

I use a spade to spoon the concrete into the void. Here's a photo:

I shove my J bolts in once I've filled and smoothed the void where they go. I'm putting in three J bolts for each 12' stretch - the outside ones approximately 12" in from each post, and the inner one in the center. I try to pack the concrete down around the bolt once it's in, then smooth it out again. If any concrete gets on the threads, you can clean it off with a wire brush.

Here's the first corner done, the front right:

A deeper shot later after I watered it down again. I wet it twice a day with the hose, and try to keep it covered with cardboard when the concrete's fresh, so it will cure properly, and not bake:

I try to always make sure my blocks are right where they should be, and make any last second adjustments, before I fill with concrete:

The bandana is soaking wet and keeps me cool.

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The front right corner uses up all my Quickcrete. Now I have to start making my own. There's a very simple formula for mixing concrete - 1 part Portland cement, to 2 parts sand, to 3 parts gravel. You stir these up dry, till it's a uniform gray mix, then start adding water. Here I'm getting materials:

If only Mishka could stay out of the sand. He's nuts about sand.

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The amount of water is highly variable. I found it depends most on how moist the sand is. The gravel also tends to have a lot of moisture in it. And on a hot dry day, the sun seems to suck out moisture while you're mixing. You just have to add water till it looks and feels right. It should be almost like a wet batter - not runny, but not too doughy either. The runny stuff goes in fast, but isn't as strong. Too dry and it's hard to work with. After I fill a void, I smooth it with a trowel. Here's the front center wall done, where the barn doors will go. Notice there are no J bolts:

I mix all the concrete in my wheelbarrow. It takes about 20 minutes to mix up a double batch. Stirring with the hoe gets tiring, and I find it hard on my back. And a double batch only fills about 6 voids. So I'm mixing wheelbarrow after wheelbarrow.

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Here's a close shot of the filled voids, every one with rod that's pounded deep into the foundation:

I've gone to wearing heavy gloves for pounding in rod, after coming down on my hand more than once.

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This is the front left of the barn stem wall finished. The pipe stubbed up is the 3/4" water line that goes directly to the shed:

Here's the deeply cut out back left corner:

All of that earth rising up over the stem wall will ultimately be removed. Land should always slope down and away from your dwellings. Even a mild slope is sufficient. I'm going to cut out a 10' wide aisle around the back and left of the barn. I'll hold back the hillside with a stone retaining wall. I might put a trench drain in front of it. I've got a cistern that needs to go back here somewhere. We plan to harvest all the rain off the roof.

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Here's where my walls come to meet and I make the final connection. Worried about keeping the block at the same elevation throughout, I went back from the front right post, and to the left, instead of going all the way around from one point, so that hopefully at the back left corner they would meet up. I used line levels, and the laser level, as I went along, but they tended to give me contradictory information. So I just continued with my 4' spirit level, and hoped for the best. And I ended up close, about 1/16" off. Here's how the walls met up at the end:

I custom cut out a corner block for the end. I use my Skil saw with a diamond blade. It works great except for all the dust. Next time I'm going to run water over what I'm cutting, to keep the dust down.

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Patty worked at grading the inside of the barn while I finished my stem wall. Here she's raking it smooth:

Taking a break, while Mishka loafs:

Here she's finished with the right side. I'm impressed. I wish I had her help up here all the time:

Here the perimeter stem wall is completely finished:

It makes a great seat.

Where I couldn't get the block around the 6x6's, I'll slather concrete within a form to tie it together.

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