Lintels (headers) above doors and windows

Building a lintel above a door and window is simple. The following suggestions/comments are based on actual jobs with VOBB and questions we have received:

1. The VOBB blocks above a door or window should have rebar on a horizontal basis. Also, we strongly recommend tat every cavity be filled with grout and rebar used on a vertical basis.

VOBB block can be drilled with a one-inch bit and the rebar inserted, such as:

   one inch hole for the rebar is drilled on a horizontal basis to make a lintel

  rebar inside a one inch horizontal hole for lintel

2. Some people prefer to cut a V in the VOBB block to lay in the rebar. See:

NOTE: See the V-cut in the block for the horizontal rebar. Some people like this rather than drilling a hole on a vertical basis as it is easier for them to align the rebar.

3. Some people prefer to cut a channel in the VOBB block to place the rebar. See:

Blocks cut to use to build a lintel above a door or window

4. Other people prefer to build the VOBB lintels on the floor/foundation and then lift them into place. See:

The first row of the VOBB blocks to make the lintels are aligned and squared. A one-inch hole is drilled in the center of the VOBB for placement of the one-half inch rebar on a horizontal basis. Afterwards, additional VOBB blocks are dry-stacked on top of the first row and properly aligned. The grout is then poured into ALL cavities with rebar added on a vertical basis.

A four-foot lintel is made for a three-foot wide wide door or window. A seven-foot lintel is made for a six-foot wide door or window. Six inches on each end are used for support to hold up the lintel. As such, both ends are left unfilled from the grout until the lintel is placed on the wall. Other VOBB blocks will be stacked on top of the lintel. All cavities will be filled with grout. All cavities for the door and window lintels should have rebar inserted on a vertical basis. Making the lintels on the foundation allows you to work with the VOBB block much easier than up on the wall. This way the lintel should be made level and square on all sides. (Be sure to put down some wood or plastic if the lintel is made on a foundation. This is so the grout will not stick to the foundation.) It is very easy to pour the dry pea gravel concrete mix DIRECTLY into the cavities. Water should be added as needed to ensure a good mix. This method will save a tremendous amount of time as compared to mixing the aggregate first and then pouring it in the cavities (unless the concrete truck and pump are readily available).

For a door or window wider than seven foot, we recommend to use at least two rows of VOBB blocks with horizontal rebar. As additional, support, you can use anchor bolts and post-tension the blocks after the grout has dried.

For doors and windows with a width up to ten feet, we suggest three horizontal rebars. For width greater than this, please consult with your local engineer or code official.

Use metal I-beams when in a high wind or hurricane surge area.

Use horizontal rebar as per qualified engineer or architect specs.