# Using 6" exterior walls in Northern NC.



## glkirk (Nov 27, 2011)

Does anyone have any thought as whether this is really that important in northern NC?
With only adding 4Rs, is it really worth the cost?
And what is the cost. There's the additional cost of studs and plate, there's the additional PITA of wider door jams and window jams. Of course insulation.
Also, I am wondering about this new insulated siding. Cost vs, value.


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## TimNJ (Sep 7, 2005)

Quieter, stronger, better R value.


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## deter (Apr 4, 2013)

I worked for a company (15 years ago) that switched from 4" to 6" exterior walls. The 6" walls could be 24c/c vs the 4" wall 16c/c which saved on qty of studs. At that time, I was told the cost difference was minor. YMMV


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## fjn (Aug 17, 2011)

deter said:


> I worked for a company (15 years ago) that switched from 4" to 6" exterior walls. The 6" walls could be 24c/c vs the 4" wall 16c/c which saved on qty of studs. At that time, I was told the cost difference was minor. YMMV





Valid point regarding the change in centers. I would up the drywall to 5/8 " though,1/2 " is kind of flimsy on 24" centers. I even like 5 / 8 " for 16" centers.:thumbsup:


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## jlhaslip (Dec 31, 2009)

Don't forget that the increase in R Value with the 6 inch studs and 24 inch spacing will help keep the house cooler when the air conditioning is on. Insulation works year round.


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## hdavis (Feb 14, 2012)

deter said:


> The 6" walls could be 24c/c vs the 4" wall 16c/c which saved on qty of studs.


2X4s can be 24" oc for a single story, so some of this depends on the house design. I'd go 2X6 in that location just for the added performance. 

5/8" drywall and sheathing rated for 24" bumps the price up from what the *cheapest* is you can do...

Around here, the stud price is basically the same using 2X4 or 2X6, but plates, corners, door and window framing is more expensive, so overall a little more for the framing materials cost.


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## ScipioAfricanus (Sep 13, 2008)

My off-hand personal OPINION is that it is not worth the extra cost in materials and/or labor. Of course, I have not run any numbers, it is just a "feeling".

Andy.


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## glkirk (Nov 27, 2011)

Thanks for all your help so far!
It probably will be some sort of one story with a room over the garage. Craftsman style, so 8 and 12 pitch roofs.
It will be stick built.
I would never consider studs at 2' OC. Just never seen around here.
I would imagine the framer would charge more too.


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## hdavis (Feb 14, 2012)

ScipioAfricanus said:


> My off-hand personal OPINION is that it is not worth the extra cost in materials and/or labor. Of course, I have not run any numbers, it is just a "feeling".
> 
> Andy.



It's getting close to mandatory up here for thermal performance. Not all AHJs require it *yet*....


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## Fouthgeneration (Jan 7, 2014)

If it is a masonry veneered house, I'd consider using foil face isocyanate type sheathing boards to get your required R-values and save a little on A.C. loads. The foil reflecting the heat of the sun warmed masonry...

Glue and screw the drywall and sheathing...

How could a framing sub charge more for less nailing? That is crazy talk.

Any 2 x 6 wall system should end up a much stronger house in general, especially in Hurricane and tornado land.

Draw the plans from the rooms outward, add the walls to the clear space needed....

Your heat loss/Heat gain in a residence is through the windows and doors, spend extra $ there for more long term savings/ milk tax rebates schemes.

keep the house as close to a globe as possible, Salt boxes are cheap to heat and cool.....


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## going_commando (Feb 19, 2013)

Not that you are worried about it, but it is easier on the trades too. Gives you more wiggle room, and let's you get insulation behind electrical boxes and whatnot which you can't do with a 2x4 wall.


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## Philament (Dec 9, 2014)

If you're moving to a 6" wall just for the added thermal properties, a continuous layer of insulation (XPS, PolyIso, Rockwool Board...) will perform much better due to the heat loss planes being in series instead of parallel. It also adds insulation over the areas that would have no added thermal benefits in going 3->6 such as headers, double top plates, rim joists and corners. 
If you're using furred out rain screens already, there isn't much of a difference in assembly other than some flashing details around windows and doors. 
I'm not familiar with the heating degree days or cooling degree days in your area, but sitting down with a local home energy consultant for a few hours with your design would give you some better insights. 
Try to look at it over the lifetime of the home, if you start looking at it from a 5 or 7 year payback, none of the options are going to make fiscal sense. But cumulatively, smaller more efficient heating/cooling appliances, reduced thermal heat loss..., things start to look more attractive.


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## deter (Apr 4, 2013)

fjn said:


> Valid point regarding the change in centers. I would up the drywall to 5/8 " though,1/2 " is kind of flimsy on 24" centers. I even like 5 / 8 " for 16" centers.:thumbsup:


agreed. that company used 5/8 throughout, on all homes


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## architectrunner (Dec 4, 2015)

Here in Maryland (Cheasapeake Bay area so similar to at least eastern NC), when the insulation had to go up from R-13 t0 R-20, half the builders went with thermal housewrap and about half went to 2x6's.

Four years later everyone is 2x6's and no one is thermal housewrap so that should tell you something. And oh yeah, all of the 2x6 framing is at 16".


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## builditguy (Nov 10, 2013)

In my opinion the cost is much higher to go with 2x6 walls. Not only does the lumber cost more. It may cost more for framing. I know I can work with 2x4 walls alot easier than 2x6. (Lifting and moving material standpoint) It also costs more in extension jambs for windows and doors.

Having said that, unless you live in an area without building codes, you either have to go with 2x6 walls or install foam R board on the exterior of 2x4 walls. By the time you buy and install the foam R board, the cost is back to where it was for 2x6.

The reason I mention an area with building codes is because of the 2012 Energy Code. In that code, the Federal government made it mandatory for all states to follow the Federal Energy code.
Yes, I know you can use Wincheck to cheat on the walls, but who wants an R-50 + to be in the attic. If someone ever has to do work up there, they don't want to wade through 30 " of insulation. (I'm guessing at 30")(or being sarcastic)

Now we just go with 2x6. I do get the stud spaces sprayed with a thin layer of foam. I realize it compress the insulation slightly, but I feel that the foam seals incredibly well. I didn't always believe in foam, but since my first blower door test, I was a firm believer.
Yes, there was foam in the 70s and that didn't turn out so well. 50 years from now we may find out something about this foam as well. My son will have to deal with that.

I only go with a thin layer of foam, because there are still some areas that don't accept foam as having an R-value. I understand the argument, but even California has accepted it, to a point.


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## Tom Struble (Mar 2, 2007)

with deeper insulated stud bays dew point happens closer to the sheathing


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## fjn (Aug 17, 2011)

Fouthgeneration said:


> If it is a masonry veneered house, I'd consider using foil face isocyanate type sheathing boards to get your required R-values and save a little on A.C. loads. The foil reflecting the heat of the sun warmed masonry...
> 
> Glue and screw the drywall and sheathing...
> 
> ...






The part I do not agree with is gluing the exterior sheating.In some areas,it is even a code violation. Over the years,I have read numerous articles that explained the problem of gluing sheating,here is one of them. The articles from JLC and FHB spoke of other reasons not to glue the sheating.



http://www.greenbuildingadvisor.com...al-questions/21842/spray-foam-and-shear-walls


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## Fouthgeneration (Jan 7, 2014)

I'm in a very low seismic area, about 700 miles from the New Madrid Fault.

So, do you renail every wall after a E-quake, gutting the house to the studs? School me please.

See the hundreds of modular framed house that remain mostly intact after being blow off their foundations, they are glued to insure fewer cracks from road delivery damage. 

I particular question the life cycle of shear wall systems that use disintegration of components as a less then optimal design. IMO:whistling Throw away buildings, the upside is they didn't crush their now homeless owners.....

The big trick of Seismic durability is to allow movement of the Earth while the building accelerate a fraction of the foundations supporting soil.


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## fjn (Aug 17, 2011)

Fouthgeneration said:


> I'm in a very low seismic area, about 700 miles from the New Madrid Fault.
> 
> So, do you renail every wall after a E-quake, gutting the house to the studs? School me please.
> 
> ...


 


Hey ! Don't shoot me,I'M just the messenger. Besides various trade publications and a few codes,along with the American Plywood Association (they should know a little about wood) they also say plywood should not be glued. They say it can cause buckling.


The middle of page # 47 speaks of that issue.


Again,remember,I'M just the messenger !

file:///C:/Users/Fred/Downloads/APA%20Engineered%20Wood%20Construction%20Guide%20-%20Wall%20Construction%20(Excerpts)%20(1).pdf


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## Fouthgeneration (Jan 7, 2014)

Sheathing can cover many of the weak points of a balloon framed building- Obviously some care must be taken with the 'solutions" 

lapping over length sheathing products increase the lifetime survival rates of wood homes. Yes some added care might have to be taken as the wood products dry to average moisture levels and dead loads are applied to the wall systems, final fastening might have to wait for dry in and curing of structural elements to enclosed conditions.

Simple practices as running a large dehumidifier after enclosure to speed wood shrinkage rates and raise the quality of the drywall, paint and stain finishes as a side benefit.

In earth Quake dominated codes Non rigid adhesives that never cure "hard or stiff" would add continuity without brittle failure modes and still absorb surplus motion energy.

I think one can build houses that don't kill their owner in an earthquake and survive intact all but the greatest shakes as centers for regrowth in disaster zone.:thumbsup:

As with any prohibition: one must dig deep into its imposition and recognize that many ideas quickly harden into absolutes when in fact they are just another stage of development of knowledge: In particular for all trades and phases of building, building codes should be considered the barely adequate minimum of design needed, one's work should surpass the minimum required by law or regulation, more so as one's skill grows.:yawn:


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