Cut Snug Blocking Without Measuring: The Saw Guard Is the Gauge

The Problem

Blocking between trusses or joists is the same short cut made over and over, each one traditionally measured in place — and each bay slightly different, so pre-cutting a stack to one length leaves half of them loose or proud.

The Technique

The trick is that the saw itself encodes a lumber thickness: from the edge of the blade guard to the blade is 1-1/2" on the creator's saw — exactly what the neighboring truss's thickness adds to the bay.

1. Verify the offset on your own saw once: measure guard edge to blade. If it's not 1-1/2", this gauge doesn't transfer.
2. Lay your blocking stock across the bay, flushed up against the far side of one truss.
3. Butt the saw's guard edge against the face of the neighboring truss.
4. Plunge cut straight down. The blade lands one truss-thickness past the guard — which is the far side of the bay — and the block drops out fitting snug.
5. Where gusset plates thicken the truss face, hold a small gap off the plate so the block doesn't come up short-tight against steel.

Cutting against a wall (stock held vertically) beats cutting flat — the block can't fall when it releases; on flat work, a second person catches.