Finally finished prepping the attic and learned a lot

Sounds familiar. When we bought our place the attic had half-done batting everywhere and the soffit vents were completely buried, so the whole thing was choking on itself. I spent two weekends pulling it all out before I could even start fresh, and my knees were not happy about it by the end. The thing that helped me most was nailing in plastic baffles from the soffits up past the wall plate before I put anything down. Without those, the new insulation just drifts over the vent channels and you end up with the same airflow problem all over again. I learned that the hard way and had to redo a section. I went with loose fill over the joists instead of rolls since my joists are shallow and the depth rulers stapled along the rafters kept me honest about coverage. A rental blower machine made quick work of it, though it took two of us because one person feeds the hopper while the other spreads in the attic. Doing it solo in August heat would have been rough. Once it was all in and evened out, the upstairs stopped turning into an oven by mid afternoon, which was the whole point. Getting quotes this week is smart, because having someone else haul and blow the material is worth every penny if your back is anything like mine.

I went a diferent route with our attic and honestly saved myself weeks of hauling. When we moved in there was about four inches of old fiberglass up there, dusty and uneven, but still doing something. Instead of ripping it out I had a crew come in and blow cellulose right over the top after I spent a day air sealing everthing myself. The sealing was the part that actually mattered, more than the depth. Every wire hole and the chase behind the furnace flue was leaking air like crazy, so I filled those with caulk and fire-rated foam before anyone set foot up there with the hose.

The blower machine rental was cheap at the local supply yard, and two of us knocked out the whole job in an afternoon. My wife fed the hopper while I ran the hose, and we flagged the joists with a ruler so I could eyeball the depth as we went.

The one thing I'd say about keeping old insulation in place is you need to know what it is first. Ours was clean fiberglass with no signs of mice or moisture, so layering over it made sense. If yours is matted, wet, or been home to critters, then yeah, pulling it out like you did is the only call.

I'm interested in the specific compaction level achieved by the loose fill when blowing it up to depth because the density, not just the volume, is what determines the thermal resistance R-value over time. If the fill is too airy, you risk excessive thermal bridging where it meets the joists. I once had an installation that seemed perfectly topped off visually, but the lack of adequate packing led to measurable heat transfer directly through the wood. Did you happen to use a specific blower setting to ensure the material was evenly distributed without excessive settling?

Agreed on the blower being a two person job, that's how we did ours too. One thing I'd add is to staple strips of old tomato stakes or paint sticks down the joists every few feet so you can eyeball your depth as you go instead of guessing. It's easy to think you've got enough material til you look back across the bay and see a low spot. Took me a whole extra bag run to fix mine.

When I did a similar cleanup in our old place, the thing that saved me was a utility knife with hook blades for carving out the matted old batts. Trying to yank them whole was impossible, they just tore into chunks, but slicing them into strips along the joists made bagging it up way faster. Bought a pack of hook blades for a few bucks and went through the whole attic in a day instead of three. One thing to ask when you get your quote next week is wether haul away of the old material is included. Some crews blow right over compressed stuff to save time, and at least one quote I got assumed I'd have it cleared myself. Made a big difference in the pricing.