Notch a Tall Post to Carry a Drop Beam

The Problem

When a drop beam runs through a post that continues up past it — a 20-footer carrying a roof or rail above the beam line — a seat cut into the top of the post isn't available. The beam needs a C-shaped seat cut out of the post's side, at exact height, deep enough for full bearing, without cutting the post in half.

The Technique

The creator's worked example: beam top at 95", built from 2x10s that actually measure 9-3/8".

1. Mark the beam's top elevation on the post face — here, 95".
2. Measure down the actual height of your beam stock — 9-3/8" for a 2x10 — and mark again. The two lines bracket where the beam will sit.
3. Set your circular saw to the notch depth and cut along both lines.
4. Make a series of relief cuts between them, and cluster several close together near one end — those tight pieces knock out first and open room for the saw.
5. Roll the post to one side face and connect the cuts to depth; flip and repeat from the other side.
6. Knock out the waste — most of the relief-cut blocks pop free — then run a reciprocating saw in behind what's left to take the back of the notch down flat.