2x6 or 2x4 walls?

[texbaylea]

Unless you are dealing with an antiquated code system, I would go with 2 x 6 on 24" centers. Used that for the kitchen addition we have put on. Plenty strong with less heat and sound conduction. For roofing sheathing go with a TechShield board wth a foil face. Be sure to put the foil face down. We are completing a complete reroofing and can already feel the difference and just have the black builders paper on the top. Next comes a white metal standing seam roof.

We also added an R30 blanket on top of the existing insulation. When we replace the existing aluminum single hung windows we will have done about all we can do to update the energy effiency of this old house.

Vernon

 

[EddieWalker]

2x4's are plenty strong enough for any home construction. The addition size of the 2x6 is greater, but it's so much overkill that you can space them out from 16in centers to 24 in centers. I don't like this because now you have to use thicker siding, sheetrock and insulation. Price is gonna be allot more. It's not just the extra buck a stud comparison, but also your plates, headers and openings.

If I had the money to burn, I'd build with 2x6's just because it's better, but when I compare the price increase, I always go back to 2x4's.

The best argument that you will find for the thicker walls is the higher R value for the thicker insulation. The flaw to this is the windows are usualy still double paned with an R value in the 3 to 4 range. Why increase your walls from and R13 with 2x4's to an R20 or more with 2x6's and still have windows with an R4 rating?????

It's like making the dam bigger and taller, but leaving the hole in the middle.

3 and 4 paned glass will give you a much higher R value, but it's very rare and extremly expensive. I've only heard of one person putting in 4 paned glass, and it's because he wasn't paying for it. I wish I knew what they cost, but from what I understand, the energy savings will never be made up in a lifetime by building a house with 4 paned windows.

Very expensive, high end windows will have a slightly higher R value, but nothing close to the R13 rating that you have in 2x4 walls. Why spend all that extra money on thicker walls, thicker insulation and more labor just to have the same energy issues from the double paned windows?

Eddie

 

[shaley]

The guy next door built with 2x6 on 24. The fit and finish on the windows and doors is not that great because the crew was not familiar with the system 20 years ago. Might be different today. We used 2x4 on 16 with 1" of R-max foam so we both have R19 in the walls.

 

[Paddy]

As Eddy said 2x4s are plenty strong. It's the insulation issue here. Investing in insulation is a good thing. The cost differece between 2x4 and 2x6 should be 5 min calculation. For 16" on center, figure 1 stud per perimeter foot. A 30x40 is 140' of ext wall. If your stud diff is $2, the upgrade is $280 for studs, The headers should have the load needs but will require more spacing. Also consider using 2x6 on 2' centers vs 2x4 on 16" centers, again dropping some what.

Alternitive: frame with 2x4s and use 2" extruded foam on the outside.

 

[stumpfield]

Alternitive: frame with 2x4s and use 2" extruded foam on the outside.

I really like this idea. Just a curious question, how do you deal with window/door frames if use 2" foam on the outside?

 

[hazmat]

Honestly if I were building a new house today, it would be SIPS (foam panels) or ICF (Insulated Concrete) for the tightest package.

If you stay with stick built, go with the spray in foam insulation & the best windows you can find (or afford). I just added icynene to my attic - huge difference vs. the R30 fiberglass. Fiberglass only performs to it's advertised R value if there is no air movement. Judging by the amount of dust embedded in the 10 year old fiberglass, it does not stop the air movement. the foam will give you the true R value. In the heat load calculations to size HVAC (Manual J) they account for air movement based on how tight the house is.

Pay attention to the orientation of the house, most windows should be on the south side & less on E W & N. There are some % numbers, but I don't remember them off the top of my head.

The better envelope you can build, the smaller & less expensive HVAC you'll need. Be sure to find a builder who is knowledgeable - some of the old school guys will oversize your HVAC equip because "2,000 sq feet = 4 tons - i know because my pappy told me so"

Lastly - I'm a huge fan of geothermal HVAC- it should be cost effective for new construction vs. a retrofit.

I heard a number the other day that 40% of energy consumed in the US goes to buildings - the manufacture of the materials & the ongoing HVAC & lighting.

 

[gotcha]

It really doesn't give a hoot what we write in here as to what is fair, good or better. It is the building code in you state, county or township that man dates what is the least one can use. I stated before that my believe is that a stick built house with 2X6 every 16" on exterior walls is the right way to go. One can do the 24" centers on the roof if one cares to, but I think they should stay with the 16" on the walls. Now again this is my opinion and the way it was taught to me in college (many, many years ago) and when I took the supervisors contractors licensing test. Again that is in my state and a few other states around me that I have pulled permits to do work. I must make myself clear that this is just for general discussion and not to tell anyone how to do their work.
The Gotcha Man

 

[AlanB]

Gotcha, what state does not allow 2 X 4 walls?

 

[gotcha]

Gotcha, what state does not allow 2 X 4 walls?

State of NH and the town is Alton. That is exterior walls.
The Gotcha Man

 

[WayneB]

State of NH and the town is Alton. That is exterior walls.
The Gotcha Man

He is right and that goes for just about any town in the state. Dunbarton requires 2 x 6 exterior walls.