Framing a house: 2X4 vs 2X6

[Dr Dave]

With 2x6 the wall will be stronger, but for the best R value, use 2x4 with 1.5" foam over OSB. This eliminates heat tranfer from studs. I did this on my home remodel, went from 1200 gal of propane to 400 gal per year. My propane dealer called on year 2 to see why I was not refilling my tank. Or for the best of both , use 2x6 with 1.5" foam, you will have to build custom door and window extensions. I am considering this on a 24x24 addition. Insulation will pay you back every month.

Dave

 

[JPRambo]

I also had my home built with 2"x6" outer walls. The insulation and cost advantages for this (in florida) is great. BUT, the heating and cooling is affected more IMO by the way air moves within the walls (put a hand by an electrical outlet when someone opens a door to the outside, and notice the air movement). After wiring 1000's of homes for many builders, sealing the penetrations from the walls into the attic area or the upper and lower floors makes a huge difference. Seal holes around the wiring and the plumbing. On of the builders had thermal imaging of a area of home and found the difference to be major. Just something to concider.

 

[gumshu]

Obviously, 2x6 construction will give you much more space for increased insulation installation. I don't think that's your problem. I framed a workshop in DeLand Fl with rought cut pine 2x4 that I stacked, dried and had pressure treated. When the inspector came for framing inspection, he said "no heat
I see". I asked him what he was talking about, and he showed me in the Florida Bldg Code, that unless framing lumber has a kiln dried stamp on it, you cannot heat the structure. Says the heat brings the bugs out of the lumber. I argued that it had been pressure treated, didn't cut any ice, had to agree that there would be no heat. Had to wait a couple of months after final to install the heat and air, so be careful.

Yes... Stamped lumber is a requirement for residential construction, just about anywhere you go. The ICC's International Codes are adopted by most states and modified according to local. There are some good discussions on the web about 2x4 vs 2x6. A lot of advantage comes from air sealing and the different types of insulation.

 

[sdkubota]

I also had my home built with 2"x6" outer walls. The insulation and cost advantages for this (in florida) is great. BUT, the heating and cooling is affected more IMO by the way air moves within the walls (put a hand by an electrical outlet when someone opens a door to the outside, and notice the air movement). After wiring 1000's of homes for many builders, sealing the penetrations from the walls into the attic area or the upper and lower floors makes a huge difference. Seal holes around the wiring and the plumbing. On of the builders had thermal imaging of a area of home and found the difference to be major. Just something to concider.

I had icynene insulation sprayed on my home when constructed. It is a foam that fills in every gap in the wall and locks the studs rock hard. No noise, no air infiltration, no (little) heat loss. The only downside is I had to have an air exchanger installed since the building envelope is so sealed and needs the introduction of fresh air.

 

[patrick_g]

Interior walls with conditioned spaces on both sides and no sound proofing issues don't need 2x6. (Especially single story or non-load bearing.) All exterior walls will profit by going with 2x6 or even 2x8 as good insulation will pay for itself over and over again in offset utility bills.

Best insulated frame house (eliminating ICF or similar) I ever studied was framed with 2x4 but the exterior walls were doubled, i.e. there was an inner and outer stud wall component to the exterior walls. The studs of the outer wall aligned with the center cavity of the inner wall (staggered.) This allowed an insulation thickness of nearly a foot (you could make it whatever thickness you want but the windows start to look like tunnels.) There was no thermal path through a stud as no stud contacted both the outside sheathing and the internal sheetrock. Very cost effective design. Got high R-value using inexpensive F/G batting. There were other energy conservative measures as well but not related to stud size.

Pat

 

[clemsonfor]

Was thinking there will be shrinkage and if not planed what Gator said you will have wavy walls as there will be little imperfections if you dont plane and shim all the studs where not flat.

 

[patrick_g]

PS High tech (AKA expensive) insulation can perform better than low tech that is a bit thicker but the cost-performance ratio champ will be thicker walls with cheaper insulation. Use a good house wrap. Build the house so tight slamming an outside door will pop your ears (Goal, not a requirement.) With sufficient insulation you will be able to heat it with a candle and cool it with an ice cube. Superinsulation will accrue dividends in reduced effort/expense for heating and cooling. As with any really tight house you need either an ERV or HRV (Energy Recovery Ventilation or Heat Recovery Ventilation system. Which? Depends on your climate, but you will need one or the other.

Regarding your own studs. Building with green studs not sufficiently cured or kiln dried will allow you to regret at your leisure what you decided in haste. Your building/walls will be out of plumb, wavy looking and a real nightmare as things twist, bow, cup, and warp over time. Maybe you can find someone to kiln dry stuff for you or someone you can trade green for cured wood. Even 2 green for one cured is not a bad deal.

Pat

 

[sdkubota]

My air exchanger is designed to strip heat/cold out of the home and transfer it into the incoming air. In theory it sounds good but the actual transfer efficency is much less then manufacturers claims. I put my exchanger on a timer so it operates a certain number of hours in a day to cut down on my energy losses.

 

[Bdavis]

My Sister and Brother-in-law finished there house in Mississippi about 2 years ago. Used pine logs he sawed with a one man sawmill to make outside paneling. Used Oak they cut down for their flooring.
He did not even try to use non kiln dried wood for framing.

Getting that pine dry without a kiln is a lot of work. He had many long sheds and it took a lot of stacking and turning.

Between the carpenter bees working on the outside and the wood beetles in their oak floor they have had a rough time. My sister just finished pulling her entire floor up. The beetles were not able to eat very far into the plywood subfloor. So she was able to pull the oak flooring up and put vinyl planks down instead.

Also you really have to be careful about using non kiln dried wood in the interior. Air conditioning is a great way to lower the mositure content of non kiln dried wood. ( it will crack)

 

[Bdavis]

Sorry about the double post double post , computer glitch

My Sister and Brother-in-law finished there house in Mississippi about 2 years ago. Used pine logs he sawed with a one man sawmill to make outside paneling. Used Oak they cut down for their flooring.
He did not even try to use non kiln dried wood for framing.

Getting that pine dry without a kiln is a lot of work. He had many long sheds and it took a lot of stacking and turning.

Between the carpenter bees working on the outside and the wood beetles in their oak floor they have had a rough time. My sister just finished pulling her entire floor up. The beetles were not able to eat very far into the plywood subfloor. So she was able to pull the oak flooring up and put vinyl planks down instead.

Also you really have to be careful about using non kiln dried wood in the interior. Air conditioning is a great way to lower the mositure content of non kiln dried wood. ( it will crack)