How to Install a Blockwall With Rebar
- 1). Choose a construction technique for the concrete block wall: either mortared joints or dry-stacked. Mortared joints are laid with about 1/2 inch of mortar between the blocks, much as bricks are laid. Dry-stack walls start with the concrete base but are firmly butted together without mortar; some special dry-stack blocks have connectors, a sort of mortise and tenon joint that holds the blocks together. Dry-stack walls are finished with surface bonding cement, which binds them firmly.
- 2). Set the rebar into the concrete foundation and slide the blocks over it, with the rebar centered in the holes in the blocks. For a freestanding wall, put it up first, then add the rebar, running it down through the blocks into the concrete foundation. Put short rebar into the foundation of a freestanding wall, at least one block high.
- 3). Fill the gaps around the rebar with concrete grout, all the way to the bottom of the wall.
- 4). Use 1/2- or 5/8-inch rebar for reinforcement; use thicker rebar for a building's walls or tall freestanding walls. Place bars at every corner and every two to four feet along a wall. Make sure the rebar goes all the way from the base to the top of the blocks. For a wall 8 feet high, use 10-foot rebar; about 2 feet of the length will go into the foundation. Install horizontal rebar or metal reinforcing plates across openings for windows or doors.
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