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.