How to Make Sure a Joist Is Flush

Measure and mark locations as called for on the blueprint for joists along each beam using a tape measure and pencil.

Locate the width of the joist lumber you’re using on the joist hanger guide tool, and align the joist in the hanger accordingly. While each guide works differently, many joist hangers tools use magnets to temporarily hold the joist hanger in place.

Square the joist hanger guide against the beam as if using a T-square on a mark made for a joist hanger in Step 1. Align the top portion of the guide flush along the top of the beam, and the lower portion flush against the beam’s side. When the hanging tool is flush on both planes, nail the joist hanger into the beam in two locations using a hammer and nails. Once the hanger is secured, remove the joist hanger from the hanging tool, and finish nailing the hanger to the beam.

Repeat Step 3 for each joist hanger. If joist hangers are positioned carefully using the guide tool, each will be nailed to the beam at the precise depth necessary.

Place joists in place in joist hangers. Tap the top of each joist with a hammer to ensure it sits at the bottom of the joist hanger before nailing it in place.