# OLD house, outside walls, plywood sheathing instead of insulation OK??



## joecaption (Nov 30, 2011)

Plywood only has an R value of about .875 per inch.
Your area calls for R 19 in the walls.
You do the math.
Just an all round very pore plan to try and do it your way.
Solid wood will just tend to transfer the hot or cold outside without any thermal bridging. 
Modern electrical codes also call for outlets along those walls.
http://www.renovation-headquarters.com/electrical-6-12-code.htm#.Ut0657Qo7IU
Surface mounted outlets would be one ugly way to do it.
I understand that's not what you wanted to hear but your way is not legal or going to work.
That trim can be removed and reused once the walls built out.


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## tcook555 (Sep 20, 2010)

I appreciate the information from Joe, I really do, and he is correct, that is not what I wanted to hear. But I should've provided some more background on my project. I totally hear what joecaption is saying though, I understand it, I understand the science and codes, etc.. and he is certainly correct. It is sound advice, and definitely the rule of thumb for construction in our modern world where we have the latest scientific data, tools, and building materials right at our fingertips to maximize our comfort and efficiency. 

BUT... (yupp u knew it was coming!)

This project of mine isn't very much concerned with comfort and efficiency. I know, I lost a lot of you by saying that, and some of you are shaking your heads in bewilderment. "What in the world is he talking about!!??" That's ok!  You see, this is more art than it is science. This restoration project is all about preserving a piece of American history, a valuable part of our past, which all to often is simply neglected/torn down/destroyed, etc.., gone forever. Yes, I am a local history buff, but I also have a background in building construction. Not everyone has an eye or appreciation for old architecture and craftsmanship, but I do and that's a huge part of this. I digress.. 

So the goal here is to RESTORE (not renovate/upgrade) this house back to the original house, as much as possible, and to preserve as much of the original house as possible (including materials and construction techniques). This means not touching the woodwork, not changing the dimensions of any space, not installing energy efficient windows, vinyl siding, etc..! You see, it's that special character and charm that you get from an old New England farmhouse, that is so important here. You just can't get that anywhere else, and that's really what this is all about. And I'm a stubborn man and I don't care what anyone says-- the moment you start messing with the original woodwork by tearing it down, cutting it down to size, building out walls, etc.. you start messing with the character, and then it's just not the same. You lose something special when you do that stuff, and that's just not something I'm willing to even consider. Sure it might not be efficient, it might not be toasty warm, it will probably get cold and drafty in the wintertime. But that's to be expected from a 200+ year old New England farmhouse, right?. And if that's the way our forefathers lived, and if that's what it takes to preserve their work and craftsmanship, and elegant, beautiful woodwork, then that's what I'm going to do. It's THAT important to me.

I know not many people will agree with me on this issue, or understand what I mean by the charm and character of an old farmhouse. And that's OK! But I also know there are a few people out there who know EXACTLY what I am talking about and share this same passion that I do for history and old architecture. You are the ones I want to hear from!

So... by now, if there's anyone still reading... I basically am looking to put plywood over the vertical planks, seal the gaps with caulk, then put drywall over the plywood, prime, and wallpaper. The wall will then be flush with the molding. And will be fairly airtight. Other than the lack of R-value by doing it like this, does anyone see any problems with doing it this way? My main concern is moisture not having an easy way out and causing problems inside the wall cavity.

I appreciate any feedback/info from anyone!! 

And SORRY for the LONG POST!!


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## joecaption (Nov 30, 2011)

Bump to move up


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## Gary in WA (Mar 11, 2009)

Just add 1/2" of XPS (2perms) then the drywall (30perms), don't seal the gaps in sheathing boards. Air seal both the fb and the drywall, offset joints (incl. fb on sheathing board), caulk/canned foam perimeter of fb; http://www.buildingscience.com/documents/information-sheets/air-barriers-airtight-drywall-approach/

Plywood (0.70perms) What type of siding?

Gary


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## Fix'n it (Mar 12, 2012)

XPS, thats what i was going to say. :yes:


and i can dig the preserving the house old character thing :thumbup:


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## Windows on Wash (Aug 30, 2011)

I can appreciate that preservation of the look as well.

Zipping up that interior wall tight and providing some thermal break will make a huge difference.


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