Framing a house: 2X4 vs 2X6

[Rock knocker]

I've done some searching and can't find the requirement for kiln dried wood. Do you have any idea where to start looking again.

Check with your permit office about rough cut. It is in the IBC, but the code enforcement has final say.

I think you're right, and I believe it speaks of using graded lumber. Now-a-days nominal framing lumber from mills is ran thru a kiln. So the code may not require KD lumber, but it probably requires graded lumber

 

[Lineman North Florida]

I'm pretty sure that here in Florida framing lumber has as others have stated has to be kiln dried, graded and stamped, with that being said I think you can use all the rough cut you want for exterior siding or interior wall covering, also pretty sure pressure treated is off limits except where the wood contacts concrete or masonry, around here where I am at codes are a real pain when building but you can go 1 county either way and they are a little more relaxed, some county's encourage building others try to discourage it. On another note I believe as hot as it is down here you are definately doing the right thing going with the 2x6's for the exterior walls, that will allow you R-19 insulation in the walls verses R-13 in the 2x4 walls. Good luck.

 

[timberland]

I would sell that timber and use proceeds to buy lumber at lumberyard....imho

 

[sdkubota]

I haven't built anything in awhile but I think a 2x6 is 1.5" x 5.25"...bunch of fossils around here.

 

[KennyG]

I haven't built anything in awhile but I think a 2x6 is 1.5" x 5.25"...bunch of fossils around here.

Actually it's 1.5 x 5.5. The dimension doesn't shrink 3/4" until you get to 8" nominal (i.e. 2 x 8 is 1.5 x 7.25). 1 x lumber only goes down 1/4 (to 3/4").

 

[Chain Bender]

I would sell that timber and use proceeds to buy lumber at lumberyard....imho

Big fine, clear saw logs around here are worth $25 - $35 a cord (2000#) a Sawn 18' 8X8 is worth about5 bucks in the log but about $55-65 when it's been PT.

 

[Raspy]

2X6 makes a lot more sense for strength. Imagine running 2" waste lines (about 2 3/8" OD) and then sneaking a water pipe in the remaining 1 1/8" and some wiring, while trying to allow for siding and sheetrock nails. Now imagine a 2 1/2" minimum hole run horizontally in your studs for vent lines and try to get a dryer vent in, etc. What's left for strength?

2X4 works, but it is the absolute minimum and brings with it a host of problems. You'll end up furring out areas, soffeting and boxing in areas to make it work. Upsize to 2X6 and you'll thank yourself later.

I just did my whole house in 2X6 and 2X8 walls with 2X10 ceiling joists. That now seems like the minimum to me and I'd go all 2X8 walls if I had it to do again. Much stronger, allows the plumbing and wiring better, more insulation, etc. Walls get pretty full in this modern age of hidden mechanical and electrical.

 

[sdkubota]

Actually it's 1.5 x 5.5. The dimension doesn't shrink 3/4" until you get to 8" nominal (i.e. 2 x 8 is 1.5 x 7.25). 1 x lumber only goes down 1/4 (to 3/4").

I stand corrected...too lazy to walk out to the garage and measure a board.

 

[GPintheMitten]

First check codes for what is required minimum. If this was a house that your son is planning on keeping for a long time, I would go with 2x6 outside walls, 2x4 inside walls.

If you have a market for the timber, I would sell it and buy kiln dried graded 2 x's. There are many reasons to have consistent sized timber in building your house. You don't want to fight the variables through the whole project and live with less than results in the end.

Price the difference in cost and labor and make the determination based on you and your son's valuation of the difference in cost and quality.

 

[radioman]

If you were buying the lumber - 2X4 is a price advantage. If you were building in northern states, 2X6's with do it yourself fiberglass insulation is a big plus in thinking ahead in terms of energy efficiency. 2X4's makes it easier with window framing as most is setup for 2x4's. windows is the biggest cost and preordering windows to fit a 2x6 can add up.

Since you are cutting your own lumber - how many more logs is it really to make enough 2x6's? just a few more right? you are only doing the outside walls and roofing. No real cost except time. you will get a better insulating value, easier time to do HVAC/plumbing/electrical/insulation work. A added plus is your son's wife/girlfriend (if any) will appreciate the additional space in window sills for plants, etc.

 

[Rock knocker]

2X4's makes it easier with window framing as most is setup for 2x4's. windows is the biggest cost and preordering windows to fit a 2x6 can add up

Actually not. It all depends on wether the window is supplied with a liner, or the liner is field constructed. And if the liner is field constructed, is it made of wood, MDF or GWB? Regardless, jam extensions are readily available.

In many areas of siesmic activity, we are finding it easier to make walls which contain DWV plumbing out of nominal 6" material because of the amount of strapping and sistering that is needed when 1 1/2" and 2" DWV pipes are ran thru plates and studs.

 

[tkappeler]

I am getting ready to break ground on a new home in a month or two. I went through the 2x4, 2x6 argument with myself. Settled on 2x4 but am using these wall sections from Raycore. R26 walls in a standard 2x4 cavity. Since I am doing the work, I did not want to deal with packing out the windows and doors with extensions. Meets all codes. Simply drop the sections down and nail top and bottom plates. Still do windows and doors in standard way and fill in above and below with cut sections of panel.

 

[Raspy]

Tom,

How do you run your plumbing and electrical in those walls?

 

[tkappeler]

Tom,

How do you run your plumbing and electrical in those walls?

You carve out some of the foam to run electric and plumbing and backfill with spray (canned) foam. Here is a video that demonstrates it:

You would be doing the same thing if you were building with SIPs anyway (kinda, sorta). I would not have plumbing in the exterior wall anyway, so it's only a few outlets and switches. I am keeping most electrical on interior walls when I can

 

[Rock knocker]

I am keeping most electrical on interior walls when I can

210.52 requires recepticles on < 6' centers in dwelling unit walls.

 

[DonnieP]

There isn't much more heat loss in a 2 x 4 framed wall then a 2 x 6 one. In a wall, a lot of the insulation value is the R value of the wood. You have two inch stud ever 16 inches, so that works out to about 1/8 of your wall is wood only R-value. I know the studs are only 1 5/8", but add in your plates, doubled studs, headers etc and you up there. You have to subtract the area of your windows and doors, that R value doesn't change. When I built my place, it would have taken nearly 20 years for heating cost reduction to pay for increased lumber cost. It was much more cost effective to put extra money into better windows or more insulation in the ceiling. Heat rises so the lose though ceiling is more than through walls. If you're milling your own lumber the cost increase is not that significant.

 

[tkappeler]

210.52 requires recepticles on < 6' centers in dwelling unit walls.

Understood, but I CAN orient my rooms so "convenience" outlets (cable TV, dual nightstands with outlets at each, etc, are on interior walls

 

[jrepp44]

Check out the "High R-Value Wall Assembly-02" it gets high scores:

High R-Value Wall Assemblies — Building Science Information

 

[Obed]

We built our house in TN and moved into it in Jan 2011. We used 2x6 framing for the exterior walls in order to have thicker insulation. Our heating and cooling costs are extremely low. Except during the hottest time of year, we can open our windows in the morning until about 10 or 11 AM then close them to keep the cool air inside the house. For days with outside temps up to 85 F, we stay quite comfortable.

I would highly recommend 2x6 framing if you can do it.

Obed

 

[Rock knocker]

You carve out some of the foam to run electric and plumbing and backfill with spray (canned) foam.

Have you got electrical bids on it? With a proposal of how the wires are to be ran? And who is responsible for removing, repairing and replacing the insualtion? Electricians hate SIPs, and want to do all their runs in the wall. You probably have envisioned vertical runs down to the crawl space or rim. The electrician probably did not bid it that way.