Why haven't my attic insulation upgrades improved the temperature at all?

The issue with those bathroom and closet areas is likely that you've created a thermal envelope that's now too good at holding onto the heat that's already in there. Insulation is a retardant, not a refrigerant. If those rooms have exterior walls—especially south-facing ones—they are still absorbing massive amounts of radiant heat thru the siding and studs. Since you've sealed the ceiling so tightly, the heat that builds up in the drywall and flooring from the day's sun has nowhere to go, essentially turning the room into a thermos. Those two corners where you stuffed fiberglass instead of baffles are definatly a weak point. If you blocked the airflow from the soffits, you've created a stagnant hot spot where heat just sits and soaks into the top plate. Fiberglass is terrible at stopping airflow; it basially acts as a filter. If you can't get a baffle in there, you might need to pull that fiberglass back an inch or two to ensure the attic can acutally breathe. If the attic air isn't moving, the underside of your roof deck is prolly hitting 150+ degrees and radiating straight through your new Rockwool.

You also need to look at **solar gain** through the walls and windows. If that closet is on a corner, it has double the exposure to the sun compared to an interior room. No amount of attic insulation will fix heat bleeding through 2x4 wall studs or an uninsulated rim joist. Check if your bathroom exhaust fan has a backdraft damper that's stuck open, too. If that flap is missing, you're basically leaving a window open to the attic 24/7.

Try purging the heat tonight by opening the windows and using a box fan to pull in cool air. Once the room temp matches the rest of the house, seal it back up and see how long it takes to climb. If it still spikes, your problem isn't the ceiling anymore—it's the walls or a lack of **CFM delivery** from your AC ducting. A small bathroom often gets a tiny 4-inch duct that simply can't compete with the radiant load of a hot exterior wall.

Reminds me of the 1980s when we thought a thick blanket of pink fiberglass solved everthing. You say you stuffed the eaves beacuse of the low pitch? That's a rookie move I made back in my first house. By packing it tight, you likely created a bridge where the heat conducts straight from the roof deck into your top plates. Back in the day, we used to use a garden rake to pull that stuff back so the soffits coud actually draw. If those closets don't have a supply vent, all that new insulation is just keeping the heat in. Is there even an air return in that part of the house? Without one, the cold air won't even enter the room.

Your decision to layer the Rockwool underneath the existing R30 fiberglass batts likely created irregular contact points and interstitial gaps where air can circulate, effectively bypassing the thermal resistance of the upper layer if the fitment isn't perfectly monolithic. Moreover, by using old cellulose to 'pack' those corners, you've likely increased the density to a point where you've compromised the R-value thru conduction, essentially turning what should be a fluffy insulator into a solid thermal bridge that's conducting the 130-degree attic heat directly into your wall plates much faster than the surrounding insulated areas can mitigate.