[pushkins]

The bricks are supporting themselves by the simple fact that they are mortared together, there is never any mortar between the bricks and the steel ledger as the two expand and contract differently and the mortar would crack and fall out within weeks of being built.

Unless your home is built with double brick (cavity construction) then the single layer of bricks that you see on the outside of your home in reality do little for supporting the structure, they are simply cosmetic. The wood framed walls support the building.

If you want to fill the "gap" (and you should) get yourself some of the "mortar repair" available at Lowe's and H.Depot, it comes in a tube and is applied with a caulk gun, it is mortar colored and when dry it's flexible.

As a rule when you "really' need to worry about brick work is when you see a crack zig zagging it's way down the mortar lines, then you need to keep an eye on it to make sure the crack isn't getting wider.