Well, found another big project to stress me out...

[Hogwildz]

Wood,
I got a few smiles with that read.
Since this is my last house, and I want what I want.... I am proceeding as planned.
The few hundred for the blower door test(s) will be put instead to the upgrades I am doing.
I can always get it done later. There is still issues of sealing the basement sill plates, windows the bilco doors that have no interior door at the basement wall etc.
I am ready to start installing the 2" polyiso I bought for the bedroom. Yes, it should still be pretty well air sealed after sealing the seams, & foaming the perimeter.
With the added R13 from the iso, that gets me close to R43, close enough. When I do the roof, I can always have a lil feller crawl in there and blow some cell in there, or just take some plywood decking sheets off and blow in from the roof. I don't care for white, paint, etc. I am a wood lover. Natural finish, that is why I am torn in replacing the T&G with new. But as budget constricts, I will re-use the dark for now. I can always install new natural to the dark later.
And to poly the who thing for door test, don't forget the peak is 3 stories, and the entire ceiling is T&G. 43' x approx. 35'. It is not a little ceiling.
Surprisingly, the house is not super dark. The light colored wall, and tall windows do a lot for light.
The "chimneys" I am still weighing in on. I am leaning heavily towards widening the bottoms, and maybe the tops also, and insulating the piss out of them with iso also.
Yes, when I do the roof, new windows will be installed. The PO put some flowery stick on film on the insides, which is now dried out, and faded, blackened and falling off. Looks like bad shrinky dinks.
Although the film still on them is baked on. Will take some scraping with razor blades.
I will be screwing lath to the bottom of the iso into the trusses to mount the T&G to. I may even seal between the lath & iso with silicone. Whats a little overkill?

The issue with the batts, is the prior owner stapled them to the inner sides of the truss chords. There is a triaxle wind tunnel gao the length of the truss chords on each side of every truss where the insualtion is up due to the batts being stapled on the sides rather then the bottoms. I pulled all the staples and reset the batts, and re-stapled them to the bottom of the truss chords. The upper side wall where the T&G were only had crappy batts also behind the T&G. I pulled that and installed Roxul R23. And drywalled over the open area. T&G will be reinstalled over the drywall directly. Already have my first coat of mud & tape on. Also sealing up wires & such.
And filling in with Roxul, where insulation was missing along the ceiling/side wall area in the attic. Just enough room to poke my head up there to see where it was needed.

Yes, it is a HUGE PITA, but I love working with my hands, and love improving my place, so it is worth it. Plus I love the challenge.
I hate it at times, but the end results are always very satisfying.

I am still weighing ordering new natural clear satin finished end matched T&G.
Found a place in NY that advertises .95 per foot. May be able to pull that out.
Now natural finish ceiling & skylights,, plus opening the skylights top & bottom, would probably be drastic, in a good way.
I'm in no rush. I was not even going to start it this year, but could not help myself. The living room, at 3 stories will be a major challenge, which I welcome, at least till I'm up there tearing away.

I do like your thoughts, but am too set in my plan.

Thanks

 

[woodgeek]

Understood. You want natural T&G, you got it. IIRC you have the lovely T&G entryway, right?

A couple things then.

With insulation, the perfect is the enemy of the good. You should not bother tweaking those batts if you can just blow cellulose over them. Any sort of gaps or defects in the batts will get covered. In a wall cavity, gap free installs are important...buried under 10" of cellulose, not so much, nor the thermal bridging of the truss chords.

Since you are doing the ceiling, it should indeed become an airsealed plane. I still like either poly or tyvek, stapled to the existing T&G, with all seams and staples taped with the appropriate tape (so it will last). Has to be easier, faster and lighter than drywall, and will work just as well. Then new T&G under. Demo-ing the existing T&G, recycling it, or dropping the existing batts is just a colossal waste of time IMO, that doesn't improve the final appearance or performance.

On polyiso. I used to love it, b/c of the super high R-value per inch, and low cost. Then I found out the R-value drops like a rock when it gets cold, iirc just below freezing,. The high R-value is b/c the bubbles are filled with a high-molecular weight gas (that you smell when you cut it), so low thermal conductivity. But at low temps the gas condenses, and then the fluid in each bubble carried heat v effectively, like a heat pipe. So, polyiso is great in hot climates....and it is great on the inner layer of a wall assembly (where it will never get too cold), but **terrible** as an outer or only insulation layer in an assembly.

I would sub either EPS or XPS foam. XPS is nicer to work with and has similar R-value per inch, but is made with a potent greenhouse gas as a blowing agent, so it is the least green insulation available....but it IS perfect for your job. Of course, when you are done, the cellulose guys can bury the chimneys up to sheathing, and you'd only have a little gap at the top after settling. Or you could box them in in the attic space, and have the box dense-packed.

I think natural T&G in the chimneys will work aok, and flaring will be nice if it is not too much of a PITA. Are they spanning the space between the trusses horizontally?

 

[Hogwildz]

Understood. You want natural T&G, you got it. IIRC you have the lovely T&G entryway, right?

A couple things then.

With insulation, the perfect is the enemy of the good. You should not bother tweaking those batts if you can just blow cellulose over them. Any sort of gaps or defects in the batts will get covered. In a wall cavity, gap free installs are important...buried under 10" of cellulose, not so much, nor the thermal bridging of the truss chords.

Since you are doing the ceiling, it should indeed become an airsealed plane. I still like either poly or tyvek, stapled to the existing T&G, with all seams and staples taped with the appropriate tape (so it will last). Has to be easier, faster and lighter than drywall, and will work just as well. Then new T&G under. Demo-ing the existing T&G, recycling it, or dropping the existing batts is just a colossal waste of time IMO, that doesn't improve the final appearance or performance.

On polyiso. I used to love it, b/c of the super high R-value per inch, and low cost. Then I found out the R-value drops like a rock when it gets cold, iirc just below freezing,. The high R-value is b/c the bubbles are filled with a high-molecular weight gas (that you smell when you cut it), so low thermal conductivity. But at low temps the gas condenses, and then the fluid in each bubble carried heat v effectively, like a heat pipe. So, polyiso is great in hot climates....and it is great on the inner layer of a wall assembly (where it will never get too cold), but **terrible** as an outer or only insulation layer in an assembly.

I would sub either EPS or XPS foam. XPS is nicer to work with and has similar R-value per inch, but is made with a potent greenhouse gas as a blowing agent, so it is the least green insulation available....but it IS perfect for your job. Of course, when you are done, the cellulose guys can bury the chimneys up to sheathing, and you'd only have a little gap at the top after settling. Or you could box them in in the attic space, and have the box dense-packed.

I think natural T&G in the chimneys will work aok, and flaring will be nice if it is not too much of a PITA. Are they spanning the space between the trusses horizontally?

With the R30 batts already there, and the R13 added inside from the iso, The iso is more on the warm side, and I expect some R value loss, but not much to make a difference. At the R43 between the two, I may not bother blown in on top of the batts. I'd rather fix the batts while the T&G is down. Again iso for air sealing + added R value + vapor barrier if sealed correctly, which it will be.
No drywall being used, except for the upper end walls that are also T&G. I am installing, mud & taping drywall on the ends, but no finish coat of mud, just tape coat & second coat, as they will be re-covered with T&G.

The skylights are 2' x 4' on 2' center trusses, running vertically between 2 trusses. 3 separate lights from each other. So the sides are good. I will definitely being opening up the bottoms more, tops, not sure yet. All I will need is to reframe the bottoms wider with some 2x across the trusses. Same at top if I do anything up there.

I did luck out, and remembered I have a stack of unfinished knotty 1" x 8" T&G pine in the garage left over from the addition. Enough to at least do the one bedroom with. It's not end matched, but not that worried about it.
I will have to seal coat & clear satin finish it all though.

And yes, the entire addition including entrance way is natural, satin clear finished T&G, walls & ceilings.
Later down the road, I will be installing natural finished log siding over the interior drywall walls. Thinking knotty hand hewn. Clean satin over them also.

 

[woodgeek]

I still think demoing the existing T&G, tweaking the batts, installing new polyiso, and then installing new T&G under the iso is a big PITA that is not necessary. I still think unless you are eager to replane and and refinish the existing stained T&G for reuse), that you leave the existing stuff in place, add a simple cheap air barrier membrane, new T&G and blow cellulose over. The cellulose pro blown might be cheaper than the purchase cost of 2" of new polyiso. The top cover will also prevent convection in the batts in cold weather. Why not choose a solution that is lower labor, comparable cost and gets you to current code insulation levels, prob R-50?

 

[blades]

Just a thought , no expert, for the ceiling, maybe dense packed cellulose, Can be installed right over fiberglass i believe, stops air migration if done correctly, and does not lose r-value as temp decline like fiberglass. this would be a contractor install as rental machines are not the correct type for dense pack.

 

[Hogwildz]

Ya gotta have fill a cavity to dense pack. If it was an unventilated roof, I might consider it. But still would have the issue of no real access or moving room in the truss area.
If I could get up there, it would be blown in cellulose. I should be good with the iso & batts.

 

[woodgeek]

Have you decided how you are going to tack up the T&G with the polyiso in there? Wood strapping screwed into the joists?

 

[blades]

Dense pak can be done in a cathedral ceiling or I would not have mentioned it.

 

[Hogwildz]

Yeap, strapping under the iso, then T&G nailed to the strapping with 16g finish nailer.
blades, dense is for cavities as much as I have read about it. Yes a standard cathedral ceiling with typical tight spaced rafters & ceiling joists may be a candidate for dense packed, but my ceiling is trusses that range from about 8" to 10" at the eaves to 3 or 4 feet high at the peak. I am already set up for vented roof, and am not a big proponent for unvented roofs.