Tech Block for Builders & Contractors

Note - Please also consult our on-line manual. A review of that material will help you understand our wall system. In most cases, we never meet or talk to the subcontractors who work on our Tech Block projects, which indicates to us that most of them understand intuitively how to deal with our system, and don't need assistance. Basically, working with Tech Block is not that unconventional.  The following information, as well as the information contained within the on-line manual, is only an example of construction methods.  It is the builders responsibility to adhere to local codes and regulations pertaining to all aspects of design and construction.

Excavator: Tech Blocks are 10-1/4" thick without the wood sheathing, and the typical trench is 16" wide by 18" deep. If we lime out or spray paint the lines, they will be to the exact exterior wall dimensions shown on the plans; in order to center the blocks on the footing, therefore, the trenches need to be dug 2-1/2" outside the lines. Excavated dirt needs to be removed from around the exterior and placed somewhere on the jobsite out of the way -- we stack our blocks up from the outside, and that area needs to be flat, level, and safe for walking, setting scaffold, etc.

Rough Plumbing: The exterior of our stem wall blocks will define the exterior of the home, and measurements can be taken from the outside edge of the blocks. The inside edge of the blocks, however, is 5/8" short of where the actual interior of the wall will be -- stem blocks don't have our 5/8" OSB attached to them, but the blocks that sit on top of them will, and you can add that measurement to the inside and still be under drywall. The thickness of wall blocks with the OSB layer is 10 and 7/8". Please keep all plumbing away from the large vertical grout channels in our blocks -- they get filled with concrete. It is also best to stub up pipes and vents just a foot or two. The blocks can be cut with any tool normally used to cut wood.

Flat Work (Concrete Slab Installer): Our stem walls are very similar to traditional stems, and you can use the tops for a screed support. However, we wet set our blocks on the just-poured footing for the perimeter walls only, and footings that don't get Tech Block walls above, such as interior footings and piers, are not handled by us. We will, however, run rebar into any interior footings that connect with the perimeter for your rebar overlap.

Doorways: Doorways are cut out by us and you need to form to the exterior and pour them solid. The consensus from most flat work subs is that you don't need expansion joints at Tech Block stem walls -- there just isn't much expansion when you have an insulated stem, and the block material can absorb some movement itself. If you have an inspector that wants one, of course, then install them. The holes you see in the tops of our blocks -- the ones with the centered vertical rebar -- fill with grout when we pour the completed wall from above, in other words, our grout goes all the way to the footing. You are not supposed to fill them.

Electrical: Most wiring chases are cut by setting a circular saw blade to a depth of about an inch and making a cut into the OSB near a block seam. That way, the block seam acts as the other cut, and you can rip off the piece of OSB that's between the cut and the seam with a claw hammer. The claw end of a hammer can also be also used if you need to remove more block material than what is left by the OSB removal, such as where there are junction boxes. Tech Block provides the metal strips that cover the wiring chases (3" and 6"), but you need to measure the linear footage and call us with the total. Most often, items that need to be attached to the exterior, like service entrance boxes, are through-bolted to the interior with all-thread.

Drywall: Obviously, Tech Block is easy to drywall to, and the walls are flat enough that some drywallers are using panel adhesive. Joint compound or adhesive is used to bond the drywall to the block material at the inside corner and window areas where the block material is exposed.

Stucco: Stucco goes on Tech Block "like a dream", as one stucco sub said, and there is no need for wire mesh except around the window and door openings, or at exterior wall transitions from foam to Tech Block, such as at parapet trusses or pop outs. Don't forget to stucco down to the footing on the outside for termite barrier.

Framing: We borrow some of the 2x4s and 2x6s from the lumber package to build a temporary frame around the  interior perimeter of the home, against which we stack our blocks. The studs in our frame are oriented "on the flat", flush, plumb, and square.  We actually screw through the frame into the OSB layer of our blocks, which keeps our walls plumb, square, and safe from being blown over by high winds. After we grout the walls, we unscrew the 2x material and stack it neatly on the site. Although this lumber will have screw holes in it, we have seen that our process tends to air cure the studs in a flat position, and they will be straight and useable. In almost all cases, we masonry set the windows, so there are no bucks to worry about, but we do prepare all door openings for bucks. We use 3/8" all-thread with #20 threads, which are grouted into our walls and protrude 1-1/2" out the sides and headers of the openings. Bucks are then bolted to the openings using the treaded ends of the all-thread. Treated 2x8 is most often used for the bucks. Unless we are instructed otherwise, our rough openings will be 5-1/2" wider and 3-1/2" taller than the nominal hinged door dimensions, and 3" wider by 1-1/2" taller than the nominal door dimensions for sliders.

If the window openings are to be bucked, we will prepare the openings with all-thread as per the door method described above.

Beam pockets are handled by the framer, and most often a Simpson MBHA (see our detail drawings, and blueprints) is attached to the top plate or through the top plate into the concrete bond beam at the tops of our walls.

Tops of walls will have 5/8" J-bolts on 48" centers, and we try to make them all the same height so that you can bang on the top plate with a hammer to mark it.