Unreinforced masonry corbel

[GeorgeTheCivilEngineer]

Hello - detail a) and b) are from the British Standard BS5628-3 and show how corbels can be made in masonry.

I've been sent c) which I am not comfortable with. This has been proposed to increase the cavity width of a cavity wall. Although it meets the geometric limits for the 1/3 offset, in my opinion it relies too much on the wall ties for this to work. This makes it vulnerable to local failure.

Am I being too conservative?

 

[HTURKAK]

The relevant clause ( copy and paste from BS5628-3 );

(5.3.6 Corbelling
Where courses are corbelled out, one above the other, for structural stability, the extent of corbelling should
not exceed that shown in Figure 14, unless the work is otherwise supported or reinforced. A corbelled
feature work may be built with restraint fixings subject to structural engineering design.)

The cornice and corbel details may introduce significant eccentricity and require consideration during design.
I would prefer simple details ..



My opinion..






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