Building Walls

Whether you have installed a stem wall for a concrete slab or a wood floor, once either floor is installed, the wall erection procedure is the same, as follows:

1. Install a loop of tie wire over each grout channel. (See detail 11.) The loop should make a complete circle and a half, have a 6" diameter, and have ends long enough to hang outside the exterior edge of the stem blocks. (Later, when you drop rebar into the 6" channel openings at the top of the wall, you will pull on these ends, which will tighten around the dropped rebar and the rebar sticking up from the footing, snugging them against each other and centering the one you dropped down from above).
   
2. Snap chalk lines on the floor where the interior face of the wall will be. This should be about 5/8" from the inside edge of the stem blocks, that is, the thickness of the OSB. Spray the line with a clear sealer.
   
3. Starting with the corners, and trying not to move the tie wire loops, set the first row of blocks to the chalk line. Don't worry about the blocks being plumb, and the corner blocks should overlap where the chalk lines come together to define a corner by 10 and 5/8", that is, the thickness of our blocks. Leave blocks out of the doorway areas for now.

The Stud Framework: General Description

Tech Block walls are built against a temporary stud framework, and the general method needs to be presented here. The studs that will be used later for interior walls will act as the temporary frame. Building against this framework eliminates the time involved in plumbing and leveling each block. The frames are easy to build, and once the frame is up, a couple of guys can stack blocks very quickly against it from the outside, while another worker drives screws through the studs into the OSB (attachment) layer from the inside. We do it this way because the walls stay square and plumb while they are being built, and there is no chance they will fall on anyone. After grouting, the 2x material is unscrewed and used by the framer for interior stud, plate, blocking, truss brace, etc.

The frame is made after the first row of blocks are placed around the perimeter by laying studs out on the slab perpendicular to each vertical grout channel, on their faces. Corners are made by screwing a couple of especially straight studs together, edge to face. A 2x6 and a 2x4 are placed against the blocks, and the channel layout is transferred to them. They are then screwed to the rest of the studs on the flat, with one screw. We use a 2x4 block to mark 3-1/2" from one end of the studs, and screw the 2x4 to the marks. This keeps what will become the lower horizontal 2x4 up off the floor so that we can see the chalk line. The 2x6 gets mounted to the ends of the studs that will become the top of the frame.

Once all of the pieces are screwed together, the framework is stood up and squared using 2x4 diagonals that are screwed from the tops of the corners down to the horizontal 2x4s. Starting at the corners, the frame is now screwed to the first row of blocks, and the weight of the blocks will help the frame stay upright. The blocks, and the frame, can then be exactly aligned to the chalk line and braced plumb. We run a string line at the top from corner to corner to make sure that we stay plumb, and we usually cross brace corner areas by installing a 2x4 diagonally across the corners at the top from 2x6 to 2x6.

As we stack the blocks, the studs will cover the vertical seams that are formed when the blocks are butted against each other. Every block should be screwed before the next row is placed on top. Make sure you are well braced against wind; we do so many projects that we have made our own adjustable steel bracing out of 1" pipe, but 2 x material can be used. (If you'd like to make your own steel bracing, contact us and we'll tell you how we do ours).

The best screws that we've found for doing the above are 2-1/2" Timberlok by 'FastenMaster'. They have a hex head design that allows you to use a nut-driver bit mounted in an electric drill for installation, and they also have a flattened, 'washer-head' design that prevents the screw from embedding itself too deeply into the 2x material.

Out on the job we use variable speed, reversible drills with side handles to drive the screws in, and to then remove them after grouting. Each block gets three screws, and the whole procedure results in a wall that stays plumb, square, and safe while it's being built, and absolutely flat after you're done -- so flat, in fact, that drywall can be installed with panel adhesive.