re: Attic air sealing and adding blown insulation

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I hired the guys to come blow in fiberglass on abt 2500 sf they topped off, was $700. In and out in 1 hr.

I sealed around my cab light boxes with spray foam the night before they showed up and it’s worked pretty well

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This might be the way to go for me.

Go up there and do all the air sealing myself and get everything nice and locked up. then just pay to have someone blow in insulation over what's already up there.

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Also interested in thoughts on adding a radiant barrier.

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It works. I had gone to blow insulation in the attic of a rental property I had just bought 3 or 4 years ago that I thought had new wiring up there. There was new wiring from a new panel into the attic and new wiring running across the attic joists. I had seen this when I inspected the place before buying. Once I was up there I started really looking at it and they hadn't connected the new wiring to outlets, etc, it was connected to old "Knob& tube" wiring. I'm guessing they fooled the previous owner into thinking the new wiring went into the walls and down to outlets. So.....I know....long story......this was end of june and I knew I couldn't blow new insulation on top of knob&tube wiring. I also knew re-wiring in the heat up there may kill me. There was a big roll of radiant barrier sitting up there so I went to work attaching that to the rafters. After I was done, and there were some gaps here and there, not a perfect job, the temp up there was manageable. I spent several hours for 4 or 5 days rewiring and that sold me on the temp drop radiant barrier can provide.

Why do you need to remove it if you’re just blowing on top of it?

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The Quiet One

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Damn. Reminds of when my house was being built, 2 days before closing HVAC tech stepped through the ceiling with a hole nearly as big but he didn’t fall though. But they repaired and re-painted the ceiling and did such a good job I would never have known the damage occurred had I not seen it myself. I was able to close on time.

Had another company come to give me a quote, this guy was much more thorough. He measured the space at 22x28, and noted that the insulation that is up there was really poorly spread, with some spots only 1-2 inches. He spread it out evenly and estimated between r10 and r25 in coverage. He said he can blow R49 cellulose and also install vent shoots (baffles) across the soffit vents for $1300. I asked him how soon could he get it on the schedule.

When it's a 90 degree day outside attic temperatures are measuring at 135-140 and we can't get the second floor under 85. I expect this should make a dramatic difference in that after learning how little insulation is really up there.

The shoots should help ventilation a lot, but there are major issues there too. He noted the sheathing is only cut about half an inch back on only one side of the ridge beam and not cut at all on the other. It's likely o ly venting about 20% what it should be. We need to decide what to do there. I'm tempted to just do gable vents on either side as opposed to cutting the roof open to either fix the ridge vent or install turtlebacks.

Sounds like the 2nd company has given you good advice. No doubt an increase in attic insulation to R49 would make a big difference and he’s spec’d it out properly for your area.

You’re certainly not getting proper attic ventilation if your ridge opening at the beam is only 1/2 inch. If I recall correctly, when I measured the width of the sheath opening at the ridge beam, to make sure my soffit vent and ridge vent area was adequate and balanced for my house, the width opening at the ridge beam was about 5 to 6 inches. There are many on-line calculators like this LINK to help you help you determine what you need.

If get those issues addressed you’ll likely go a long way to resolving that upstairs summer heat issue.