Progress Report

This week I worked pretty much exclusively on stacking blocks for the tornado shelter walls. I had a couple of hurdles to overcome; such as how to best join two walls when they meet at a “T” as shown in the first pic. At first I thought I would embed full-sized blocks in the exterior wall on every other course. Every time you do that you have to use a half block to fill the remaining void. Using half block isn’t a problem, but every time you do you create three butt joints adjacent to each other, and I definitely didn’t like that. To me all those butt joints just represent weak points in the wall, so as far as I am concerned, the fewer butt joints the better. With all my thinking and cogitating during the design phase of the block walls, this is something I didn’t realize would happen.

So, here’s where we are. The exterior wall (north wall) will be built normally with no half blocks used in it. That makes the interior wall a free-standing wall, not connected directly (with overlapping block) into the north wall. There needs to be a good, strong way to connect these two walls at the T-joint. Rebar comes to the rescue, especially since I have lots of rebar scraps sitting around. I decided to make rebar “hooks” (pic 2) which fit into notches cut in the tops of blocks (pic 3). These hooks extend down into those block 5” on each side, giving lots of surface area for concrete to grab on too. There will be five rebar hooks used in the T-joint, one every other course of block.

Even though the joint is pretty much built, and half-way concreted I'd still be interested in your other ideas and suggestions.