AAC Masonry Products
(continued)
Lintels
End bearing for lintels should normally be not less than 8". Where stresses under lintel bearing will exceed permissible values (e.g. under heavy concentrated loads), concrete spreaders or padstones should be incorporated.
Cold bridging at lintel positions can be avoided by the use of AAC in association with appropriate types of lintels. These allow the insulating properties of AAC blocks to be continuous across the wall face and can facilitate the placing of subsequent door and window fasteners.
If multiple courses of U-Block are used, notching is required to allow concrete to get to the lowest course.
Always pre-wet the u-block before pouring the grout.
AACPA
Installation Manual
End Page 7