Hello all,

As part of my efforts to air seal and insulate my home, I just purchased a new FLIR infrared camera. First, what a cool tool for an energy nerd! It has instantly identified areas of the home on which to focus.

For the most part, everything I found was straightforward – a couple of electrical holes that need to be sealed from the attic and a painful realization that can lights, even with rockwool covers, are big areas of loss. There is however one area that I don’t know how or even if I can address. On virtually every exterior wall there is a heat plume coming from where the ceiling and exterior walls meet. I’m guessing this is normal since it is really hard to insulate at these corners. But this is going to bug me until I know whether or not I can address it.

I have three thoughts on this on how to address this. I am looking for feedback:

1) I own 4″ thick 4×8 sheets of leftover polyiso insulation. With a little effort I could cut these into triangular sections that would fit behind crown moulding (which does not currently exist). That would give me a pretty thick triangular section of polyiso blanketing the corners.
2) Something else that I’ve not thought of.
3) Give up and accept that my house is good enough.

Our home is 60 years old and will never win any world records for energy efficiency. However, we’ve made a ton of progress. We have cut our energy bill in half from lots of retro-insulating, air sealing, and a new 95% radiant system. More importantly the house is more comfortable. Anyway, I’m not trying to make this home LEED certified. Just curious if there is a relatively easy way to reduce the heat loss in these corners.

Thanks,
Brian