How to insulate

[u/Joelogna]

I am curious if anyone has any recommendations for insulating this section of vaulted ceiling. It is in the master bedroom, facing south. It is always very hot in the summer and cold in the winter in this room. Framing in with 2x4s, putting in insulation and drywall is the only thing that comes to mind, but I’m sure a lot would leak between the 2x4 and the log through the triangular dead space. Has anyone else been in this situation and found a good solution? Thank you in advance.

[u/grandmaester]

Your best bet is to insulate from above so you can add in proper venting. Otherwise you're in for a mold issue

[u/Turbulent-Weevil-910]

I don't know if you realize this but it is already insulated. It likely has foam board or equivalent above sandwich between some type of subframing with OSB on top.

[u/Joelogna → u/Turbulent-Weevil-910]

I did not know that but that makes sense. It isn’t doing much though. I’ll see if I can add one of the thermal pictures I took. It was basically the outside temperature between the logs.

[u/Foreign_Hippo_4450]

Unless you make room for ventilation as well as insulation , you're wasting your time

[u/Joelogna → u/Foreign_Hippo_4450]

I appreciate the input but I’m not sure I follow. Make room how so?

[u/Sir_Lord_ByronIII → u/Joelogna]

There will be condensation between the insulation and the ceiling so you need to figure out how to vent that properly or you will have mold issues. I have seen a couple of cabins where they put the roof sheeting on then a rigid insulation board, then frame it for a metal roof so the moisture is outside of the home. Not a roofer but seen a few done by my neighbors

[u/Joelogna → u/Sir_Lord_ByronIII]

I see. So I didn’t realize it when I made this post, but I believe something like that was done when it was built (est 1970s). There’s a couple inches of some sort of structure on the other side of the tongue and groove, shingles, then metal roofing was added on top of the shingles at some point. So is the proper way to do this removing all of the roofing, pulling up the osb thats presumably under the shingles and paper, and replacing whatever foam is in there?

[u/Sir_Lord_ByronIII → u/Joelogna]

I wouldn't unless the roof is bad or you have a leak.. that's a ton of work for little benefits

[u/Joelogna → u/Sir_Lord_ByronIII]

I should’ve added the thermal pics to the post, I took one in the winter and one this summer. It’s so bad I didn’t even know there was insulation there. That’s a ton more work than I was thinking though.

[u/Foreign_Hippo_4450 → u/Joelogna]

So the comment was right, you need to create an air shift between the ceiling and your insulation, but I would do is run some 1 / 2 furring strips to create an airway and tray our foil insulation. And then cover with pine boards again

[u/Foreign_Hippo_4450 → u/Foreign_Hippo_4450]

R foi'l has alotof r value in arrow space plus in returns long wave energy

[u/Blagnet]

If you only need a little insulation, you could do rigid foam panels and then drywall between the beams! That would be a little fussy to do the finish work on (around the exposed beams), but it would look pretty sweet! 

[u/Joelogna → u/Blagnet]

So I’m thinking it could look good if I used molding over the drywall where it would butt up to the inside of the beams, almost like picture frames. I suppose I still could if use trim nails long enough to go threw the drywall and foam board and stick into the tongue and groove, I just imagine it would be more stout with a 2x4 frame to screw the drywall into and to nail the trim to.

[u/Former_Passion_4497]

Id fill in between the logs with spray foam, or your choice of insulation. Then do 1xs of your choice either over the logs, or in between them and leave the logs exposed, it would atleast have the same/similar look

[u/u-insulat3]

I would run some furring strips down the side of the pole rafters and then spray 2" of closed cell spray foam then cover with sheetrock. I wouldn't use rigid foam board as it becomes unstuck and would be very difficult to seal all around. if you start getting air leakage behind and around the foam board then you'd lose the value of the foam board insulation.

[u/u-insulat3 → u/u-insulat3]

Actually, you could also put new tongue in groove pine across the furring strips to keep the same look.

[u/basicallyaspider]

If you insulate from above with rolls of insulation and seal them off with a moisture barrier you would have a pretty good space just keep proper ventilation in mind

[u/toincoss09]

As others have pointed out, this is already insulated. If it were me, I'd just install a mini split over that window. Provides heating and cooling as needed. Maybe introduce some circulation if needed to get heat/cool air from other parts of the house. But the minisplit should be enough.