Does a broken depth gauge mean I’m missing insulation?

That broken gauge piece usually means the installers were trimming them to fit specific framing, not necessarily that they shorted you on the actual insulation. In Phoenix attics, it's common to have 2x6 or 2x8 joists. If the crew is stapling those plastic rulers to the side of a joist, they often snap the bottom off so the "zero" mark lines up with the top of the wood rather than the drywall ceiling. It’s also possible they just broke one while trying to staple it in a tight corner near the eaves. Finding a scrap doesn't automatically mean your R-value is missing six inches; it's often just sloppy cleanup. To get a real reading, you have to push a tape measure or a yardstick all the way down until it hits the **drywall**. Measuring from the top of the joist will give you a false number. In our climate, you're typically looking for an R-49 or R-60 rating. For cellulose, that usually translates to a thickness between 14 and 19 inches. If you poke through the fluff and find that it's deep enough to bury the joists by a significant margin, you're likely fine. Check your paperwork for the **bag count** as well. This is actually more important than the depth gauges. The manufacturer’s chart tells the installers exactly how many bags are needed to cover your square footage at a specific R-value. If the bag count on the invoice matches what’s required for your house, the depth should be correct. Installers sometimes get lazy with the rulers because they’re just visual aids for the inspector, but the bag count doesn't lie. Go back up there with a headlamp and check a few spots toward the center of the attic, away from the hatch. Cellulose settles about 10-20% over the first month, so a good crew will overblow it slightly. If you’re seeing a consistent 15+ inches, you’re in good shape. But if you find spots where you can see the tops of the joists or the coverage is under a foot, that’s when you call the manager back out to finish the job.

One must meticulously verify the manufacturer of that specific gauge, as brands like Owens Corning or GreenFiber have distinct calibration markers that often account for initial fluffing versus the eventual settled density, which is a nuance many installers overlook. You shold realy inspect the 'minimum settled thickness' column on the coverage chart located on the packaging, becasue if they utilized a high-density blower setting, the initial loft might appear deceptive compared to the long-term thermal performance you'll actualy experiance during a Phoenix summer. It would also be prudent to confirm wheather those gauges were specifically designed for cellulose or fiberglass, as the scale increments often differ significantly to account for the material-specific R-value per inch.

Totally agree about the rulers being unreliable; those things snap if you even look at them wrong during a hot install. One thing people forget to look for is the official attic card that is supposed to be stapled to a truss right by the hatch. It’s basicly the birth certificate for your insulation job. It shold have the date, the bag count, and the R-value filled out and signed by the lead. If they didn't leave that card, or if it's blank, that’s a way bigger indicator of a rushed job than a broken gauge. It’s your best proof if you ever have a home inspection later.

Quick update—I checked for that attic card like one of you suggested and found it right by the hatch. It listed the exact bag count, wich matches the R-value I paid for. Turns out that broken ruler was just a scrap from when they were trimming them to fit my 2x6 joists. everthing looks solid now. Thanks for the help!