My attic is insulated with faced fiberglass batts between the joists. I've noticed large insects (yellow jackets, box elder and lady bugs) mysteriously getting in to the house over time and come to the conclusion that they come in via holes in the can lights and smoke detector.
When I was up there sealing some leaky duct work, I pulled up some batts and noticed that they don't lie flat on the ceiling sheetrock, because of the crosswise lath or strapping boards. It seems the insects are getting in under the insulation around the soffits and they craw in this open channel to the light fixtures.
Well, I'm going to air seal the light fixture anyways... but if insects get in there, warm house air can also exit. I've seen this problem in the side family room roof area that abuts to my garage. Unfortunately in the main attic, I have a hipped roof and I cannot get all the way down to top plate of the outer walls. (at least I haven't tried hard yet)
What would be a good idea to "seal" this gap near the top plate? I doubt I can get my hands down there, yet alone see the actual junction.
I was thinking maybe putting about a lath board height of loose fill on the sheet rock in the outer foot or two. I wouldn't get a proper vapor barrier, but it's better than the status quo.
Other ideas??
Dave.