The brick arches a little bit here but you need to install shoring ASAP. In other words as you do the removals. In addition, we are usually working on old buildings that have a variety of masonry conditions (poor) that are not being repaired to “as new” condition. Ironically I have had discussions with architects that suggest, “Hey, the steel lintel is bowed way down and is not supporting the brick, then we take out the lintel and the brick does not move so why put in a new lintel that is only going to rust again?” Scary but true! Take a look at the brick coursing on a typical running bond and then on a real “flat arch”. If you bring some physics into it, you will notice that on a flat arch the lower portion of the arch is somewhat in tension (not working) and the upper portion is in compression (working) then look at the height of the head joint in a running bond brick wall and you will see there ain’t enough of the brick in compression to really work. It is often luck that these things don’t unravel more often.

Eric Hammarberg, Assoc. AIA
Vice President
Thornton Tomasetti
51 Madison Avenue
New York, NY  10010
T 917.661.7800  F 917.661.7801  
D 917.661.8160  
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From: [log in to unmask] [mailto:[log in to unmask]]
Sent: Sunday, November 12, 2006 4:24 PM
To: [log in to unmask]
Subject: [BP] question about lintel repairs on steel-framed buildings

Lintel repairs all around me... After the three or four rows of brick are removed to get at the rusting lintel, I notice that 2x4 stock is used to prop up the now free-hanging brick above the repair void. 

At what point, if left unsupported, will these bricks fall?  I assume they are held in place only by friction, ties and back up mortar.   I mean, do you have to brace them every brick or two, or can you just do it at the end of the day.

c

PS did you see that documentary on the tunnels of The Great Escape, a couple of years ago?  They found the German POW camp, excavated the tunnels, found the rails, the wires, everything.