Finally crawled up into my attic and measured the insulation, felt pretty good about it

I had a similar moment a couple of years back when I was trying to figure out why my upstairs felt stuffier than it should. My situation was different because I had used batts instead of the blown-in kind, and I was checking the depth myself to make sure I met a certain R-value standard for my climate. It turned out my framing was set up quite tightly between the joists, and even though I had the right material, the actual finished depth was barely adequate for what the energy audit suggested I needed.

It made me realize that just getting the right type of material isn't enough; the spacing and the sheer volume of material in the cavities make a huge difference. I ended up hiring someone to blow in some of the fiberglass around the edges and between the batts to fill those gaps, which made a noticeable improvement in how the thermal envelope performed. It's less about just piling it high and more about making sure every inch is covered properly.

It was a frustrating realization to see that what seemed like a complete installation was acutally incomplete due to poor installation practices. It changed how I look at insulation projects now.

I ran into somethig diferent when I was insulating a ranch built in the seventies last fall. It wasn't about the depth being excessive, but more about the density of the material itself. I was trying to acheeve a target R-value that the manufacturer promised for the specific brand I bought, and I noticed that the installers were just blowing it on with the lowest setting to get it distributed evenly across the entire floor area. It created massive 'hot spots' where the density was super high, right next to areas where it was barely enough to cover the subfloor.

Even though the average thickness might have looked okay in a glance, the thermal performance was inconsistent from room to room. I ended up having to go back and use a denser setting in certain areas to make sure I wasn't leaving pockets of poor insulation under the tongue and groove work. It’s strange how one layer can be uneven even if the overall depth seems to meet code. It made me wonder if people measuring just by the visual depth are missing the real picture of how much they are actually saving on the energy bill. The thickness is just one piece of the puzzle when you are looking at true insulation efficiency.

Those foot-through-the-ceiling moments are no joke, been there myself. What helped me was taking an old paint stir stick and shoving it down to the drywall every couple feet to mark where the joists run, then hopping between those spots. Also worth checking if the attic has a walkway or board path laid down, mine did and it saved a lot of guessing. Funny how the stuff that's allready working quietly is the last thing we think to look at. Mine turned out to be shallower than yours but still plenty once I actually measured instead of eyeballing it from the hatch.

Funny timing, I poked my head into my attic last weekend for the first time since moving in and it's the opposite problem. Mine was blown in maybe fifteen years ago and it's settled flat in a bunch of spots, you can actually see the joists poking through now. Made me wonder if the original depth was fine and it's just sunk over the years. Guessing a top-up is in my future. Did you happen to eyeball wheather yours has packed down anywhere, or is it still fluffy even where it's deep?