Beam pocket cut 6 inches too low in a block wall: how to rebuild the bearing

IRC Section R606.6.3 says a beam or girder resting on masonry needs at least 3 inches of bearing, measured along the beam, on solid masonry at least 4 inches thick. The code allows two alternatives: a metal bearing plate sized to spread the load, or a continuous reinforced masonry member that projects at least 4 inches from the wall face. Hollow block with open cells under the beam is not solid masonry.

That leaves a few ways to close a 5- to 6-inch gap. The pocket floor can be built back up with solid units or grout-filled block, then topped with a steel plate or steel shims at the right height. Steel shims can carry real load. AISC design guidance says shim stacks need a sensible width-to-height ratio so they cannot topple or shift, and stacks are sometimes tack-welded together. A remodeler on Fine Homebuilding's forum wrote that inspectors where he works accept only steel or composite shims under beams, never wood.

A wood beam brings one more rule. Under IRC Section R317.1, the end of a wood girder set into an exterior masonry or concrete wall must be decay-resistant or preservative-treated if it has less than half an inch of air at the top, sides and end. Builders on the same forum describe bedding wood beams on pressure-treated stock or galvanized steel and shimming the sides so the beam cannot roll in an oversized pocket.

The Reddit post did not say whether the beam is steel or wood or what load it carries. Both decide how much bearing area the fix needs and whether the plate has to be sized by an engineer under the code's metal plate option.