Tn 18A web-nov06. indd

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 in. (3.2 to 6.4 

mm) space should be left at each end of the lintel. These 

measures form a pocket that allows movement of the 

steel angle within the brickwork. Locating the expansion 

joint adjacent to the window will influence the dead weight 

of the masonry bearing on the lintel. Instead of the usual 

triangular loading, the full weight of the masonry above 

the angle should be assumed to bear on the lintel. See 

Technical Note 31B for more information about steel lintel 

design. If a vertical expansion joint cannot be built in this 

manner, do not place it alongside the opening. 

Junctions. Expansion joints should be located at 

junctions of walls with different environmental exposures 

or support conditions. Separate portions of brickwork 

exposed to different climatic conditions should be 

separated with expansion joints since each area will 

move differently. An exterior wall containing brickwork 

that extends through glazing into a building’s interior 

should have an expansion joint separating the exterior 

brickwork from the interior brickwork. You may need 

to use expansion joints to separate adjacent walls of 

different heights to avoid cracking caused by differential 

movement, particularly when the height difference is very 

large. Examples are shown in 

Figure 7

.

Parapets. Parapets with masonry exposed on the back 

side are exposed on three sides to extremes of moisture 

and temperature and may experience substantially 

different movement from that of the wall below. Parapets 

also lack the dead load of masonry above to help resist 

movement. Therefore, extend all vertical expansion joints 

through parapets. Since parapets are subject to more 

movement than the wall below, they must be treated 

differently. When vertical expansion joints are spaced 

more than 15 ft (4.6 m) apart, the placement and design of 

expansion joints through parapets need to accommodate 

this additional movement. In this situation, make