# 2x4 24" OC Studs



## ckheath (Sep 29, 2017)

We are having a small 24' X 28' home built on a cement slab in mid Michigan. I just discovered the builder used 2x4 studs 24" on center framing. The trusses are also 24" on center and the roof has a 4/12 pitch. The home is built in mid Michigan where snow fall can get pretty heavy. We are having insulation blown in.

I see that 24" OC is done with 2x6 studs, but he used 2x4 studs on all walls. Does anyone see a problem with this? Maybe its ok because the home is so small?

The walls have not been closed up yet as the plumbing and electrical still need to be run. If this is a problem, would adding more studs now be beneficial? I mean, some walls are smaller than 24" OC due to windows and doors, but I could split the 24" on the rest and add 2X4's.

Opinions and suggestions would be greatly appreciated!! Thank you!


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## mark sr (Jun 13, 2017)

I've painted quite a few new houses over the years that had 24" spacing with the stud walls. On exterior walls there is a minimum sheathing requirement. You may have missed it but the specs would have been in the original plans, if 24" centers wasn't specified - then your builder is at fault.


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## ckheath (Sep 29, 2017)

mark sr said:


> I've painted quite a few new houses over the years that had 24" spacing with the stud walls. On exterior walls there is a minimum sheathing requirement. You may have missed it but the specs would have been in the original plans, if 24" centers wasn't specified - then your builder is at fault.


Thank you for the response. Any idea what the minimum sheathing requirement is for 2x4 studs spaced 24" OC? 

Thanks again!


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## carpdad (Oct 11, 2010)

In NJ and efficiency framing/insulation is not what I grew up with, so what I can say about it is anecdotal. First you can do is ask your builder and if applicable, your town inspector. You can also search with words such as "why 2x6 stud walls".

What I know is that you don't have to have 2x6 stud wall for bearing capacity. The total of "efficient" building includes using less lumber (24" spacing) and more insulation (2x6). As long as joists or truss lands on top of studs, 2x4 is capable of carrying the loads. This kind of framing also calls for single top plate, so joist or truss can't land mid bay. They always have to be directly on the bearing stud. I think 1/2" outside sheathing is ok, but you need 5/8" drywall. 

If using long span I joists or such, they need more bearing area. Then you may need 2x6 wall. You must have a plan and contract. What does it say and what did you want? Was it assumed to be a budget build? If you started with assumptions, you better get things straightened out before sinking more money into it.


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## Bud9051 (Nov 11, 2015)

A 2x4 wall will probably need a layer of rigid insulation, inside, to reach the total minimum insulation level. The 2009 IECC codes which are often adopted by local authorities specifies R-20 cavity or r-13 cavity with a layer r-5 rigid added over the studs.
https://energycode.pnl.gov/EnergyCodeReqs/?state=Michigan

16" OC will give you a straighter wall but 2x4's 24" OC (IMO) is cutting corners in the wrong place. As suggested, check your building plans (submitted with permit application) and check local authority as they have the final word.

Adding extra studs between the 24" OC makes insulation difficult which will result in a poor job. It would also fail the r-20 cavity fill as the average r-value would drop.

With a slope that low your trusses should have included a raised heel to provide space for the insulation above the outside walls. Again, check local codes.

Hoof sheathing should be thicker than the 7/16th osb.
Drywall needs to be a minimum of 1/2" possibly 5/8".

Remember, code requirements are the minimum, they are not best practices. It would have been very easy to build that house to a higher standard and then enjoy years of comfort and lower energy costs. Shame on someone, probably the builder.

Bud


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## ckheath (Sep 29, 2017)

carpdad said:


> In NJ and efficiency framing/insulation is not what I grew up with, so what I can say about it is anecdotal. First you can do is ask your builder and if applicable, your town inspector. You can also search with words such as "why 2x6 stud walls".
> 
> What I know is that you don't have to have 2x6 stud wall for bearing capacity. The total of "efficient" building includes using less lumber (24" spacing) and more insulation (2x6). As long as joists or truss lands on top of studs, 2x4 is capable of carrying the loads. This kind of framing also calls for single top plate, so joist or truss can't land mid bay. They always have to be directly on the bearing stud. I think 1/2" outside sheathing is ok, but you need 5/8" drywall.
> 
> If using long span I joists or such, they need more bearing area. Then you may need 2x6 wall. You must have a plan and contract. What does it say and what did you want? Was it assumed to be a budget build? If you started with assumptions, you better get things straightened out before sinking more money into it.



Yea, I put a lot of trust into a builder friend of mine. Hard situation indeed.... Thank you for your input.


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## mark sr (Jun 13, 2017)

> Any idea what the minimum sheathing requirement is for 2x4 studs spaced 24" OC?


It might be 1/2" but I don't know for sure. Your local permit office/inspector would know.


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## stick\shift (Mar 23, 2015)

Have you checked with the local AHJ that this meets code? Around here, outside walls have to be 2x6 for insulating purposes.


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## Bud9051 (Nov 11, 2015)

AHJ = Authority Having Jurisdiction

Bud


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## ckheath (Sep 29, 2017)

Thank you everyone for the replies. I am going to be in contact with the county building inspector in an hour to get a clear answer on all this. I really do appreciate your input. I will post what I find out.


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## Nealtw (Jun 22, 2017)

It's been 20 years since I have seen 2x4 exterior walls and I have never seen 24" on center exterior wall All good for interior if your about saving 25 studs..

Trusses a 24" is normal.


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## ckheath (Sep 29, 2017)

Bud9051 said:


> A 2x4 wall will probably need a layer of rigid insulation, inside, to reach the total minimum insulation level. The 2009 IECC codes which are often adopted by local authorities specifies R-20 cavity or r-13 cavity with a layer r-5 rigid added over the studs.
> https://energycode.pnl.gov/EnergyCodeReqs/?state=Michigan
> 
> 16" OC will give you a straighter wall but 2x4's 24" OC (IMO) is cutting corners in the wrong place. As suggested, check your building plans (submitted with permit application) and check local authority as they have the final word.
> ...



Im still waiting for the inspector to call back, but had a question about the "rigid insulation" mentioned above. I was planning on having cellulose insulation blown in the exterior walls, does this change anything or would I still need the rigid insulation?

Thanks again!


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## NotyeruncleBob (Mar 9, 2017)

As noted, you need to see what the plans spec for framing, what the county requires, and what your contract specs. 
If all the answers above are that 2x4 24 OC is acceptable, then you need to look at what to do to get the level of insulation that you want. If I were in your position and in your climate, I'd probably go with a Bonfig wall assembly: http://www.finehomebuilding.com/2014/11/26/breaking-the-thermal-bridge
This article might need a digital subscription to Fine Homebuilding (which is completely worth it!) but here's the gist of it... You pad out the thickness of the wall using strips of high density EPS foam with 1x3 attached. You get a couple inches of added wall depth and a thermal break without having to put full sheets of foam on either inside or outside of the wall. It's cheaper. Way more R value. Fairly easy to do. 
I'm about to start a new build this fall that is speccing this method, but with 2x6 24 OC to get a 7 1/2" thick wall.


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## BIG Johnson (Apr 9, 2017)

Michigan is under the 2015 IECC. Your builder must be using the performance path. 


http://scotthomeinspection.com/energy-code-compliance-prescriptive-vs-performance-path/


2x4 is strong enough as long as he's keeping the load path in line, truss to foundation. I'd personally use 5/8 osb on a 4/12 pitch but 1/2" is acceptable if you don't mind dips in your roof between the trusses.


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## Bud9051 (Nov 11, 2015)

Thanks Big. I haven't kept up with who has or has not moved beyond the 2009 IECC guidance. Did a search and here is a good explanation of the difference.
http://www.builderonline.com/building/code/2015-iecc-what-you-need-to-know_o

Judging from the op's explanation I would doubt that this house is going through a HERS oversight as the savings achieved would be eaten up by the design and review process. Again, local code officials will know.

Bud


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## BIG Johnson (Apr 9, 2017)

Bud9051 said:


> Judging from the op's explanation I would doubt that this house is going through a HERS oversight as the savings achieved would be eaten up by the design and review process. Again, local code officials will know.
> 
> Bud


Unless the builder is building the same house multiple times. It's about $600-$800.


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## carpdad (Oct 11, 2010)

2x4 wall will hold max r13 insulation with cellulose. XPS rigid boards are added outside on top of the sheathing for additional insulation and to cut down on insulating value lost by uninsulated materials, such as 2x studs. I am using the boards to add insulation (I have r11) and more important, close up all holes and gaps in the old 1x10 sheathing. So it depends on how and what you are using it for. House wrap, like tyvek, is used on top of boards to drain any water as well as stop air coming in. Insulation happens by stopping air movement and if air is moving around the insulation, you lose a lot of energy heating and cooling.
If you use 2x6 wall, you can put more insulation into it. Using 24" spacing means less studs that are not insulated. So you can save by not using outside boards. If you caulk the sheathing gaps, you don't have to seal from outside with wraps and tapes. (Tape also will not last min 40 yrs until the next siding job. Once tape comes off, you lose air seal.)
A builder is not likely to follow small time intensive details. But it pays big once you start spending money heating and cooling. Either pay for it or diy the small details everyday. My cheap take on it was: after osb sheathing was installed I used cheapest caulk I could find, which was DAP painters caulk. I think I used up 2 cases. From inside I sealed 4 sides of a stud bay as well as sheathing joints. Push the caulk into all joints and gaps. This stops outside air. Then r13 fiberglass. 15 lb tar paper over osb while I did some inside work then second layer 15 lb paper, then vinyl siding. Tar paper will wrinkle up, esp if rained on, but vinyl went up fine.

Don't know what's dictated in your area, but insulation pays big. Your question was 2x4 load cap, but my take on it turned into insulation.:smile: If 2x4 wall 24" spacing is what you have, you can add insulation, if that's what you want. 24" spacing also brings up bracing value of outside sheathing. Ask or search if 1/2" sheathing is good enough with 2x4 wall 24" oc. You may have to add more nails or let in cross bracing from inside.


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## BIG Johnson (Apr 9, 2017)

Don't use cheap (DAP or any other brand) painters caulk for ANYTHING it doesn't stretch at all, it just cracks. For sealing up a house use white 100% silicone. For painters work use a minimum of dynaflex 230. Windows and doors use OSI quad sealant.


You can get R-15 batts for 2x4 but it's very expensive and still doesn't meet IECC 2015 for walls.


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## ckheath (Sep 29, 2017)

I still havent heard from the inspector.... Im gonna call him again today. Im really feeling lost here. We saved for this build and really looked forward to it. I thought we had a builder we could trust. In no way is saving 1 to 3 thousand worth it to me. Given the choice, I would have said pay the extra money....

Anyway, Im running some numbers to make sense of all this until I hear from the inspector. This is based on 24' x 28' frame. The 2x4 stud were run directly below the trusses. I was thinking I could add a 2x6 against every 2x4 then build the out the gap created at the top and bottom with 2x2 boards. My math says I will be taking away 78" total of wall space while adding 104" total of depth to the wall. So I will gain 26" of insulation across the entire homes walls.

For the record, he already put up the siding so external foam insulation isnt really an option that is easy.

Thoughts? Thank you everyone!!


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## mark sr (Jun 13, 2017)

You could alternatively attach a 2x2 to the interior side of the 2x4s to gain the extra depth. Either way you'd want to do it prior to the electrician doing his rough in.


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## ckheath (Sep 29, 2017)

I thought about that too, but thought the inspector might look at me funny. That would be a ton easier and allow for way more insulation.


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## mark sr (Jun 13, 2017)

I doubt an inspector would have an issue with it but you could always run it by him first.


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## 123pugsy (Oct 6, 2012)

Blown cellulose for walls? Won't that eventually settle leaving gaps at the top of all the walls?

Or did you mean spray foam? I believe if you filled the 2x4 walls with that, it may be adequate r value, not sure though.


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## ckheath (Sep 29, 2017)

Honestly, Im not sure. I want to use whatever gives the best r value, price does not matter. I thought cellulose was the best, but maybe im mistaken.


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## ckheath (Sep 29, 2017)

http://cellulose.org/GreenestInsula...the-myth-about-cellulose-insulation-settling/ 

If Im reading this correctly, they build settling into coverage charts so once it does settle it wont wall below r values. 

Again, Im open to whatever insulation solution gives me the best r value. I appreciate all input! Thank you!!!


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## carpdad (Oct 11, 2010)

You don't have a substandard house. 2x4's are good bones. You can just add 2x2 (stay away from end nailing to avoid splits) to get the 2x6, but I'd double check your insulator and your knowledge of "dense packing" cellulose (since you've lost the trust). I think it depends on the speed of moving the hose. Check the videos - may have your answer there. Instead of thinking about what may be wrong, spend your time how to improve. You will need 2x2 along the floor for the trims - 2x4 would be better nailer blocks. Use 5/8 drywall to support dense cellulose.

Time to talk to your builder. NO MATTER what may happen, you must talk and straighten out the problems. Esp as you say this is your last house. You don't have to reason or negotiate anything. Ask, listen and put your complaints here for review. The builder too much of ass to listen and explain? Maybe you are.:smile: Been there in both ways.


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## ckheath (Sep 29, 2017)

Ok, I just spoke with the building inspector. He says he is good with building the walls out if thats what we decide to do. He also said its possible to meet the required r value with the 2x4 walls if we were to use spray foam. Im going to have another company come in and give me prices both ways. Thank you Everyone for your help!!


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## BIG Johnson (Apr 9, 2017)

123pugsy said:


> Blown cellulose for walls? Won't that eventually settle leaving gaps at the top of all the walls?
> 
> Or did you mean spray foam? I believe if you filled the 2x4 walls with that, it may be adequate r value, not sure though.


I think 2" or 3" of spray foam is enough. OP needs to talk to his builder. If it fails inspection it will be the builders responsibility to fix it. No way would I just go and add 2x2's everywhere. Window and door jambs will have to be custom, which isn't a big deal but maybe the builder already ordered the windows with jambs.


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## ckheath (Sep 29, 2017)

carpdad said:


> You don't have a substandard house. 2x4's are good bones. You can just add 2x2 (stay away from end nailing to avoid splits) to get the 2x6, but I'd double check your insulator and your knowledge of "dense packing" cellulose (since you've lost the trust). I think it depends on the speed of moving the hose. Check the videos - may have your answer there. Instead of thinking about what may be wrong, spend your time how to improve. You will need 2x2 along the floor for the trims - 2x4 would be better nailer blocks. Use 5/8 drywall to support dense cellulose.
> 
> Time to talk to your builder. NO MATTER what may happen, you must talk and straighten out the problems. Esp as you say this is your last house. You don't have to reason or negotiate anything. Ask, listen and put your complaints here for review. The builder too much of ass to listen and explain? Maybe you are.:smile: Been there in both ways.


I dont think anyone was an ass here. I honestly believe he thought I would want to save that money. I was simply looking for outside opinions, thank you for yours.


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## BIG Johnson (Apr 9, 2017)

ckheath said:


> Ok, I just spoke with the building inspector. He says he is good with building the walls out if thats what we decide to do. He also said its possible to meet the required r value with the 2x4 walls if we were to use spray foam. Im going to have another company come in and give me prices both ways. Thank you Everyone for your help!!


It's pretty expensive, probably $10K, blown in cellulose would have been closer to $1K. Blown in cellulose would have been fine. Not having the performance path paperwork doesn't make blown in cellulose any less effective. Now this problem is on the radar of your building official, He's going to be looking for thicker walls or the receipt for spray foam. Michigan doesn't have an insulation inspection so you probably never would have been busted. It might be a good idea to get the HERS performance path work up done and go back to what your builder had originally planned to do.


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## carpdad (Oct 11, 2010)

Don't know where you are, but spray foam can be tricky. If the ambient temperature isn't high enough, chemicals don't cure and become toxic. Or applied too fast. Make sure the company is big enough to handle complete removal. That's just anecdotal so double check what you know.


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## ckheath (Sep 29, 2017)

Yes, the windows, doors and jambs are installed. I just spoke with an insulation company and they said to leave the 2x4 studs and use spray foam to meet r value codes. So there it is, the building is fine and we can meet codes.

For the record, the builder is a friend of mine and he really does want to save me money. We do talk, but the 2x4 vs 2x6 construction was overlooked. Then as I looked into it and discovered varying opinions, not just from here, and I needed to understand the situation better. I feel a LOT better now that I understand. Im sure if it were off season, the builder and I could have worked through details better, but he is working his ass off before winter. In the end, I believe we will love our new home!!


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## BIG Johnson (Apr 9, 2017)

ckheath said:


> Yes, the windows, doors and jambs are installed. I just spoke with an insulation company and they said to leave the 2x4 studs and use spray foam to meet r value codes. So there it is, the building is fine and we can meet codes.
> 
> For the record, the builder is a friend of mine and he really does want to save me money. We do talk, but the 2x4 vs 2x6 construction was overlooked. Then as I looked into it and discovered varying opinions, not just from here, and I needed to understand the situation better. I feel a LOT better now that I understand. Im sure if it were off season, the builder and I could have worked through details better, but he is working his ass off before winter. In the end, I believe we will love our new home!!



http://www.cbc.ca/news/spray-foam-insulation-can-make-some-homes-unlivable-1.2224287


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## ckheath (Sep 29, 2017)

BIG Johnson said:


> It's pretty expensive, probably $10K, blown in cellulose would have been closer to $1K. Blown in cellulose would have been fine. Not having the performance path paperwork doesn't make blown in cellulose any less effective. Now this problem is on the radar of your building official, He's going to be looking for thicker walls or the receipt for spray foam. Michigan doesn't have an insulation inspection so you probably never would have been busted. It might be a good idea to get the HERS performance path work up done and go back to what your builder had originally planned to do.



I guess thats the problem, this HERS performance path has never been mentioned to me from the builder. Insulation was not not discussed until after framing, siding, and roofing.

I believe it was already on the inspector radar as soon as he heard 2x4 walls. The first thing out of his mouth was "you are going to have a problem bringing that to insulation code". Thats when he talked to me about options. He seemed very willing to talk it out with me.

It is what it is now. As long as there is a way to complete this according to code, Im good.

Thanks again!


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## ckheath (Sep 29, 2017)

big johnson said:


> http://www.cbc.ca/news/spray-foam-insulation-can-make-some-homes-unlivable-1.2224287


i give up!!!!


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## Bud9051 (Nov 11, 2015)

You are stuck with a difficult situation, the builder is a friend and the house is well past changing directions. Spray foam is an option, but you still need to discuss open cell vs closed cell. Technically I believe the closed cell would be the only way to meet code requirements but much more expensive. Open cell costs less but has a lower r-value per inch and the end result isn't that much different. The key would be discussing this with your inspector and getting approval in advance. Here is a link on the open vs closed decision.

http://www.greenbuildingadvisor.com...ng-closed-cell-spray-foam-between-studs-waste

My personal choice would be to cover the inside of the studs with 1" of rigid foam with cavities filled with r-15 batt insulation. Not only does this meet code requirements (needs to be verified) but it covers the inside of all framing (the thermal bridging) resulting in a much better r-value for the wall assembly. It also avoids the risks related to spray foam, especially during colder weather as carpdad mentioned. From a construction point of view it also allows changes to wiring or other after it is insulated. A closed cell foam make any future work difficult.

I'll let you read.
Bud


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## NotyeruncleBob (Mar 9, 2017)

ckheath said:


> i give up!!!!


Don't. 
Just take a deep breath, think about the finished product and the nice home you will have, exhale...ah, feel better?
Let's walk through this and get to a good solution. 
Your ultimate goal is to have a good, well insulated home. 
Your reality is that right now you have a 2x4 framed shell. 
You have a couple really good options to make this still work. 
#1. Keep the walls at 2x4 and spray foam it. 
Don't get too hung up on the horror stories. There are a lot of companies doing good work and if you do your homework then you won't have anything to worry about. Spray foam also creates a good air seal which is also very important, if not more important than a simple R value number. 
#2. Pad out the 2x4 to make it thicker and use a more conventional insulation. 
This will be more lumber and labor, but you'll save on the insulation part if you go with dense pack cellulose or mineral wool batts. 
You can get your whole wall R value way up by using the Bonfig wall assembly I mentioned earlier. The EPS foam strips and then 1x3s on each stud will pad out the wall to get you the room for more insulation, but the really cool (or warm) part is that the foam breaks the thermal bridge of the studs to the outside and makes the whole wall much more efficient. 

As long as the inspector will sign off on them, either of these is a perfectly acceptable solution.


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## NotyeruncleBob (Mar 9, 2017)

123pugsy said:


> Blown cellulose for walls? Won't that eventually settle leaving gaps at the top of all the walls?


You're thinking of loose fill cellulose that's used in attics. That stuff does settle a little bit, which is fine in that application. 
Dense pack cellulose used in wall cavities doesn't settle due to how densely it's packed in there. It's a really cool system and works much better than fiberglass batts since it fills all the little voids and gives a much much better air seal than what's possible with fiberglass. It's a specialty installation and not widely available everywhere, so you may not have come across it out in the wild yet.


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## NotyeruncleBob (Mar 9, 2017)

ckheath said:


> The 2x4 stud were run directly below the trusses.


That is really good. That creates a direct load path from the roof down to the foundation. 



ckheath said:


> I was thinking I could add a 2x6 against every 2x4 then build the out the gap created at the top and bottom with 2x2 boards.


No need to add a 2x6 since the 2x4 is adequate to hold the house up structurally. The only thing you'd want to do in this scenario is pad out the thickness of the walls which you could do with 2x2s nailed to the face of each stud, or with EPS foam strips and 1x3 strapping nailed to each stud. 
Nailing on 2x2s should be a fairly quick and easy thing to do since they're not structural. You don't even have to be perfect with them touching each other like you would with the framing that's holding up the house. Gang cut the 2x2s and go nuts! You'd be done in a day or two.


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## BIG Johnson (Apr 9, 2017)

NotyeruncleBob said:


> That is really good. That creates a direct load path from the roof down to the foundation.



Not only really good, it's code for 2x4 walls.


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## BIG Johnson (Apr 9, 2017)

NotyeruncleBob said:


> Nailing on 2x2s should be a fairly quick and easy thing to do since they're not structural. You don't even have to be perfect with them touching each other like you would with the framing that's holding up the house. Gang cut the 2x2s and go nuts! You'd be done in a day or two.



Uh, window and door jambs. 

It'd take him a whole day just to find a few hundred half way decent 2x2's. 

I'd [get my builder to] ask the building official if I could amend the permit and use the HERS performance rating. See if my builder would split the cost as he was the one who screwed up and sounds like shouldn't be building houses.


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## 123pugsy (Oct 6, 2012)

Don't fear the foam.

It's the 5 LB, I believe, closed cell that you must use.

I wish I would have done the whole house now looking back.


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## ckheath (Sep 29, 2017)

NotyeruncleBob said:


> Don't.
> Just take a deep breath, think about the finished product and the nice home you will have, exhale...ah, feel better?
> Let's walk through this and get to a good solution.
> Your ultimate goal is to have a good, well insulated home.
> ...


Thank you for taking the time to write that out. I really like this as a solution and must have been what the inspector was talking about this morning. Im going to verify with him tomorrow. That link had a pdf that was very informative.


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## NotyeruncleBob (Mar 9, 2017)

BIG Johnson said:


> Uh, window and door jambs.


Trimming out the windows shouldn't be an issue unless they came with the jamb and sill attached. 
The doors, well yeah, you could be right there, but I think that since this house was supposed to be framed 2x6 then the doors could be already jambed for that width. Besides, even if they're not it's only what, two, three doors? The interior walls wouldn't be changing at all so it's just the entry doors. Even paying the local mill shop to change the door jambs would be cheaper than the extra $$ spent heating an inefficient home for a month.


BIG Johnson said:


> It'd take him a whole day just to find a few hundred half way decent 2x2's.


Why? A little bow won't matter in this application since they're being nailed to the studs. If they're bowing out you can press them flush when you're nailing them off. The structural part is done, so these are just space fillers. As long as they're nailed tight to the studs it doesn't matter if they're a little out of plumb right to left. You just have to provide a place for the drywall to get nailed to. It wouldn't be any worse than any stud wall you're likely to come across to begin with.


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## NotyeruncleBob (Mar 9, 2017)

BIG Johnson said:


> Not only really good, it's code for 2x4 walls.


Yep. You're right. That's why it's really good that he's actually got a structurally sound house that he can work with at this point. It'd be a whole other conversation if it was a mashup of 16 over 24 or vice versa.


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## BIG Johnson (Apr 9, 2017)

NotyeruncleBob said:


> Trimming out the windows shouldn't be an issue unless they came with the jamb and sill attached.
> The doors, well yeah, you could be right there, but I think that since this house was supposed to be framed 2x6 then the doors could be already jambed for that width. Besides, even if they're not it's only what, two, three doors? The interior walls wouldn't be changing at all so it's just the entry doors. Even paying the local mill shop to change the door jambs would be cheaper than the extra $$ spent heating an inefficient home for a month.
> 
> Why? A little bow won't matter in this application since they're being nailed to the studs. If they're bowing out you can press them flush when you're nailing them off. The structural part is done, so these are just space fillers. As long as they're nailed tight to the studs it doesn't matter if they're a little out of plumb right to left. You just have to provide a place for the drywall to get nailed to. It wouldn't be any worse than any stud wall you're likely to come across to begin with.



95% of new homes built by me are still being built with 2x4's 16" OC with dense cellulose at ~R14. It passes 2015 IECC. these builders build the same 3 or 4 houses over and over and pay for a performance rating that shows R14 in 2x4 is just as good as R19 in 2x6 walls. It's fine for them, it's fine for OP, he just has to pay for the service to prove it. 

Btw, 16" OC 2x4 wall studs with double top plate do not have to be lined up with the trusses.


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## ront02769 (Nov 28, 2008)

Two bye four walls at 16 or 24 inch centers were the norm for many mNy years.....with no issues relative to the amount of bearing that they have for joists, rafters, whatever. Two bye six walls are there not because of their greater compressive strength but simply because they can contain more insulation. That said, where I am you can't build a new residential home with two bye four exterior walls. Ron


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## NotyeruncleBob (Mar 9, 2017)

BIG Johnson said:


> Btw, 16" OC 2x4 wall studs with double top plate do not have to be lined up with the trusses.


True. Somehow I had OVE/Advanced framing in mind since we were talking about studs on 24" centers, but I guess the OP never actually said that. Advanced framing requires the direct load paths over single top plates. I'm still not sold on the single top plate part of OVE, but the rest of it makes sense.


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## BIG Johnson (Apr 9, 2017)

ront02769 said:


> Two bye four walls at 16 or 24 inch centers were the norm for many mNy years.....with no issues relative to the amount of bearing that they have for joists, rafters, whatever. Two bye six walls are there not because of their greater compressive strength but simply because they can contain more insulation. That said, where I am you can't build a new residential home with two bye four exterior walls. Ron


You're in MA. They don't let you guys do anything. What a energy code are you under?


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