a. Offset Lintels. For modular window and door openings, you will often use precast concrete
lintels designed with an offset on the underside. Steel angles are also used with lintels to support blocks
over openings. You must install the blocks with the offset on the underside to fit modular openings
Figure 2-30. Precast concrete lintels with an offset
b. Metal Pates. Place a noncorroding metal plate under the ends of lintels wherever there are
control joints. This permits lintels to give slightly and helps the control joints to function properly.
Place a full bed of mortar over this metal plate to distribute the lintel load evenly.
2-28. Sills. You will usually install precast concrete sills after you have built the walls. Be sure to
tightly fill the joints at the ends of the sill with mortar or a caulking compound (Figure 2-31).