Just wondering about people's experiences and reasons for choosing one over the other. We're wanting to build the 20' wide 2-story cottage. Any thoughts???
-Preston
I used 2x6s (on 16" centers) and feel it was a good decision.
Pros: Stronger. Less warping & a better quality stud was available, more room for insulation, plumbing, electrical cables.
Cons: A little more expensive, but not enough to consider going with 2x4s, a little heavier to work with, but no big deal.
QuoteI used 2x6s (on 16" centers) and feel it was a good decision.
Pros: Stronger. Less warping & a better quality stud was available, more room for insulation, plumbing, electrical cables.
Cons: A little more expensive, but not enough to consider going with 2x4s, a little heavier to work with, but no big deal.
Any reason you stayed with 16's instead of 24?
I am currently building the 20' 2 story with 2x6's 16 o.c. Here in California the building code won't allow less. In most places you can probably go 24"o.c. with no problems. Structurally I don't think it makes a big difference.
Chuck
We're talking exterior walls, right? 2x4's will do nicely inside except for some walls and plumbing requirements.
Interesting question and one that has been and will continue to be debated. The usual reason for choosing 2x6 over 2x4 is to get the extra insulation. However if you're a sloppy builder you may have more air infiltration in a 2x6 wall than a careful builder with 2x4's.
Proper sealing against air filtration, under the sills, in the corners, around plumbing and electrical penetrations, ductwork, etc. is at least as important as more insulation. Air moving within a wall will have heat moving from one place to another and usually in the direction you don't want.
If you use 2x6's you can increase the stud spacing to 24" in most locations instead of the traditional 16". But if you do that beware of trying to use 1/2" drywall on the interior. You'll end up with wavy walls. Use 5/8" or other more rigid wall materials.
The wider spacing does have the advantage of increasing the effective avergae R-value of the wall as the wood stud has a much lower R-value than the usual fiberglass batts. Fewer studs = more fiberglass.
2x4 walls with fiberglass batts plus a 1 to 1 1/2" layer of foam board on the exterior is another good insulation technique. This has the bonus of limiting the thermal leakage thru the studs as well as providing an air barrier.
2x6 will cost more; more wood, more insulation, windows & doors may cost more or extra dollars to extend the jambs... but there will be a payback in energy savings over time.
Another factor to consider is whether or not your building must meet the Dept of Energy, International Energy Conservation Code. It much more difficult, maybe impossible, to meet it with conventional 2x4 exterior walls. Check with your permit/code/inspection dept first. The answer as to what to use may be dictated by their rules. http://www.energycodes.gov/rescheck/
Thanks for the great link MountainDon, how is installing siding over the rigid foam? I won't be using vinyl, probably a traditional slat or t&g siding. To make sure I understand this, the foam would replace the plywood sheathing and you would then want a vapor barrier between the batting insulation and the drywall?
The example I saw recently had the usual 7/16 OSB installed as exterior sheathing with the 1" extruded foam over that. Then it was stuccoed. The interior was drywalled.
Siding would need longer fasteners to be used. Depending on the materials being used you might have to be careful about crushing the foam.
I've also seen articles where the foam board was applied without the OSB or plywood... not sure if that was some special kind of structural foam or not.
Information re building better, higher energy efficient homes may be found at http://www.buildingscienceconsulting.com/index.html
There are lots of variations as examples. Choose by basic weather type on this page. (specific as built homes shown down near the page bottom.
http://www.buildingscienceconsulting.com/designsthatwork/default.htm
One caveat. They show a different inside corner framing method that uses clips for securing drywall. In practice they are less than an ideal drywall securing method.
OSB or plywood may still be required for bracing - at least on some areas.
QuoteOSB or plywood may still be required for bracing - at least on some areas.
As always.... check with the applicable officials. :-/
To meet most code required R values 2x6 is pretty much a neccesity for an exterior wall.
It really depends on how the locals have written their version of the gospel. Some governing bodies have mandated that nothing less than 2x6 walls will do, no if's ands or buts. Others, like NM, have declared that all new residential construction must meet the Dept of Energy, International Energy Conservation Code 2003. The RESchek program is approved and promoted for determining compliance with the standard. This rule may be superseded locally as long as the changes are no less stringent than the state rules.
You run the RESchek program with your values and print out the data sheet when the program says it's within compliance. The bldg. dept may check the figures, they may not, they're not telling, but that sheet becomes part of the approved plans.
This does give leeway in how to achieve the required energy code. For a ridiculous example; R120 ceiling, R11 walls and R42 floors will get a passing grade even though it may not be too practical. More realistically it's fairly easy to get R38 ceiling, R13 walls (2x4) with R5 (continuous layer 1" foam) for a total R18 and R30 floors approved as long as you are using good windows. (Using a post/beam elevated foundation for this example.) Note the number of windows and their U-factor is taken into account as well as the number of exterior doors, skylights, etc.
I was simply trying to point out that the near automatic choice of using 2x6 walls for better insulation is not the only way, nor necessarily the best way to "skin that cat". Again, the place to start is your local code, then design from there.
I ran this a while back for myself, but misplaced the numbers. So, being me, I re-ran the numbers for 2x4 vs 2x6.
I'm basing this comparison of the cost of a 2x4 and 2x6 framed walls on my basic cabin plan size, 14 x 26, 364 sq. ft. For comparison I've chosen a single exterior door, three windows (one each 6x4, 4x4 and 3x3) and deleted the equivalent insulation area. The framing estimates include the sill plate, studs, and two top plates as well as jack studs for doors and windows. I know there's likely a piece or two of lumber not accounted for but if so, they're missing from both estimates so this should be accurate enough for comparison.
The 2x4 wall studs are assumed to be 16" O.C. The 2x6 studs 24" O.C. Both estimates include 7/16" OSB on the exterior. Nails, sealants, etc. are NOT included. Actual doors and windows are not included either. Pricing obtained from my local Home Depot yesterday.
2x4, 16" OC sheathed walls $445
2x6, 24" OC sheathed walls $510
2x6 is approx 14.5% [$65] more than 2x4
ADD R13 fiberglass to the 2x4 and R19 to the 2x6
2x4, 16" OC sheathed, plus fiberglass insulation $695
2x6, 24" OC sheathed, plus fiberglass insulation $810
2x6 is approx 16.5% [$115] more than 2x4
ADD 1" of R5 foam to the exterior of the 2x4 framing.
2x4, 16" OC sheathed, plus fiberglass insulation, plus 1" foam $960
this costs 18% [$150] more than the 2x6 with fiberglass only
and 38% [$265] more than plain 2x4, R13
Dollar increases are very low compared to the total materials cost of the building shell, let alone the completed cabin.
Of course you could go 2x6, 24" OC, with exterior foam added.
Framing, sheathing, foam comes to $1075 :-/
So right now, I'm leaning towards the 2x4 framing plus exterior foam, as this is for a small three season cabin. Wood stove heat and there's lots of wood. Winter is a crap shoot regarding snow... too much and ya' need a snowmobile. And I'm not a real snow person anymore. YMMV
Thanks for sharing that MountainDon. I'm leaning towards the 2x6 16 oc with at least 1/2" exterior foam over sheathed walls. I think this will provide with an insulating factor that should stay pretty current for awhile. We're trying to avoid (Well I've pretty much decided) no forced air even though we'll be in the mountains. Taking Advantage of the Passive Solar Tools and SuperInsulation, I think we'll do alright. We're thinking of using Electric Radiant Floors as well as at least 1, maybe 2-3 Fireplaces for heat when it's needed.
Neat to see the differences once again!
Preston nothing against Don but I am with you. I found it alot easier to work with 2X6 when it comes to wiring, plumbing and the like. Also it gives a better nailing surface when building walls. If I were to build another two story as I did a couple of years ago I would opt for the 2X6. It just makes me feel better when I am sleeping on the second floor.
With 2x6 at 24" OC, you don't need headers for windows that have a 22 1/2" rough opening. A *big* money saver.
Bob
QuoteA *big* money saver.
Well, Yes and/or No.
Even if you can do that, it seems to me if you end up installing 2 smaller windows in a space/room where a single larger window might also be used, you will spend more on the 2 individual windows than you would spend on one larger window plus header materials.
Just my opinion.
Bob, I can see what you're saying, however in my case we're going to be doing larger windows. It's definetly something to consider. I don't really like drywall, so thinking about a heavier/thicker piece of that stuff makes me cringe. I've done a lot of it so you think i'd get over it. I'd do 3 entire roofs to 1 room of drywall.
QuoteA *big* money saver.
Okay, okay. I think the money saved per window might roughly approximate the grocery store sticker on the malbec I was nursing when I wrote that. Still, no cripple studs, no jack studs, no headers, no weakened load bearing studs. It's got to be easier and simpler.
Bob
QuoteQuoteIt's got to be easier and simpler. Bob
I guess I can't argue with that, Bob.
I see the choice of window size, window type, and window location as a purely personal decision, except for the demands of meeting code. Other than code restrictions, there is no single right way to do windows. On a purely personal basis I don't see the designing and building of headered windows or doors as a problem. I enjoy the design process. I enjoy the satisfaction derived from the challenge of accurately translating the drawings into the finished building. I would rather put a little more effort into the whole job and end up with a finished product that fulfilled my needs or desires.
I have a great view available to my cabin. I see no point in skimping on the window size. I paid for the view. Certainly that 6 ft x 4 ft window is going to be a heat hole. No argument there. But it's more economical to me to do that one large window than to have three narrower windows. I want the view and the daylight it will provide to the interior, more than the higher thermal efficiency of a solid wall, or a single small window, in that position.
I guess my real point is that in my 61+ years of living I have made some decisions based purely on the immediate economic cost to me. I have regretted some of those decisions later. I try to achieve a better balance of immediate cost, future cost and personal satisfaction with the results. I mentioned somewhere on this forum that I will also be building shutters, probably insulated, for the cabin windows. I will have the option of having them open or closed. Again, not the cheapest way to build the walls and windows, but one that will give me the best compromise including my personal satisfaction and happiness. IMO.
There's an old British saying, "penny wise, pound foolish" [the "pound" being their currency before the Euro.] I believe it applies to many things in life.
'Nuff said... just a personal view on walls and windows.
I'm just finishing roughing in our place. My arthrites made me hire a few laid off framers for three days work. Anyway, I went with 2 X 4s. Mostly cause it was just easier and I saves me some space. I can only use 50 of my 100 wide lot for building, so for a garage and future 1 1/2 I need it all. Plus...what's with the safety issue? Think it's not founded. "I would opt for the 2X6. It just makes me feel better when I am sleeping on the second floor. " I live in Wisconsin, and I can't remember ever hearing of a house "falling down". Tornados take em all out like there toothpicks....so
Anyway, I went with 2 X 4 and was only going to sheet the corners with OSB. I changed my mind and sheeted it all (did feel I needed to do that for safety....givin the big top this garage has! We are just finishing up sheeting the whole thing in 1" DOW. I didn't approach the decision too scientificaly, I just wanted the thermal break outside the studs like my city house has.
Looks like you ended up with what I've spent much time deliberating about, Frank. :)
Quote..what's with the safety issue? Think it's not founded.
Back home I grew up in a neighborhood full of 1 1/2 ti 2 1/2 story houses, stick built with 2x4's Never saw one of them fall down either. They're now 100 years old and for the most part still there, but mostly updated, renovated, ext. foam added, etc. But underneath the same old, same old.
G/L and I hope to see some pictures when you can.
OK I'll play devil's advocate. I'm seriously thinking of using 2x8's. Locally a 12' 2x8 is only 25¢ more than a 12' 2x6. The 2x8's are really nice southern yellow pine and the 2x6's (and 4's) are poor quality spf. It winds up being a couple hundred buck's and the added insulation can't hurt.
I want the next house to be very well insulated, but the primary motivation is the sorry quality of the spf .. whitewoods framing lumber.
Ken Kern mentioned that 2x4 stud houses were already overbuilt. A 2x4 will support much more than the little bit it is called on to support in a stick built house.
Funny you should mention.... John C.
Just today I saw a truck/flatbed rig parked with a load of what appeared to be pre-fab wall sections. They were mighty thick looking. I went over and discovered what appeared to be a knock down house. Framed with 2x10's!! :o , sheathed with OSB and those black fiberboard panels. 8 foot sections. I couldn't see the sides to see if they were cut out for windows or doors or if they were insulated in any manner. It was a NM transport, but have no idea where it was going or coming from.
Interesting debate on this issue. I've worked on dozens of houses framed with 2x4's and never really saw an issue with them. A 2x6 house more solid when you slam a door and is quieter I'd say due to more insulation but if you live in the woods that's not really an issue anyway. The gain from R 13 to R 19 is like less than 1% so I don't see why all the fuss. You'd do better to sheath with foam which creates a thermal break at the studs. As small as most of the houses people here are building you won't save much on your bills by going from 2x4 to 2x6. I'd put the insulation in the floor and the roof or buy better windows if it was my money.
Scott
So Scott are you saying that there is just a 1% gain between R-19 that R-13. If that is so then why are we paying more for R-19 . 3-1/2 verses 6-1/2 Huh
Well, that forced me to delve a little deeper. I fired up my REScheck program and loaded the information I'd saved for my cabin. It's set up with R38 ceilings, R30 raised insulated floor, 3 high quality U-factor 0.35 windows and one door in a 14 x 26 foot structure.
When I run walls of R13 vs. walls of R19 the program gives me a 13.3% difference in the energy efficiency. The 2x4 R13 walls fail the test. In NM that means the building would not meet code and would not have the plans approved.
When I run the R19 walls vs R13 walls plus R5 foam on the exterior there is a 12.2% difference in energy efficiency rating. This also passes code like the 2x6 R19 walls do. The program does not take the effect of the foam being a thermal break at the studs. It would seem that the foam over 2x4 would beat the real world performance of plain 2x6 though.
:-/ :-/ :-/
FYI, the R19 2x6 walls beat the code by 3.3% while the R13 + R5 walls beat code by 2.2%. There are a number of codes ranging from 1992 through 2006. NM is one of the states that follows one of the strictest codes, 2003 IECC.
These figures are for my mountain location. When I run the same numbers through my year round residential location those same values (R13+R5) come out to better code by 27.9%
I have mentioned the REScheck program before. For the curious here's where you can find a link
http://www.countryplans.com/cgi-bin/yabb2/YaBB.pl?num=1177221623
Well I should have been more specific I guess. 1% relative to no insulation at all is what I meant. Don's program comes up with 13.3% which I assume is better relative to R-13. So relative to no inulation it would be 1.33% so I was off 1/2% sorry. As I understand R value R-1 = no insulation but also no air movment. R-10 = 10% of the heat flow of R-1. R-100 would be 1% of R-1 and so on. Unless I'm wrong on this which I admit I could be R-19 is not that much better than R-13 relative to no insulation at all.
Scott
My goal in using the 2x6 vs a 2x4 isn't really about money, it's about stayin warm without forced air :) It was nice to hear what you had to say about immediate cost vs future satisfaction Don! <<That thought has been playing through my head I just couldn't get it out in words.
ScottA, You mentioned 2x8x12's, you'll be cutting a lot to get an 8 foot wall.
QuoteAs I understand R value R-1 = no insulation but also no air movment. R-10 = 10% of the heat flow of R-1. R-100 would be 1% of R-1 and so on. .....R-19 is not that much better than R-13 relative to no insulation at all.
I'm trying to understand what is being said here and having trouble.
I understand, R-value to be: A measure of a material's resistance to heat flow (BTU's per hour, through one square foot of wall area for one degree Fahrenheit temperature difference). R value is derived from the U-factor of a material; that's how well a material conducts heat. R value is the reciprocal of the U-factor.
R-value figures do not apply only to things we recognize as insulation, they apply to all materials. A 1/2" of plywood is rated at R=0.63, 1/2" of drywall at R=0.45, a 4 inch common brick receives an R value of 0.80. A single pane window glass has an R of 1.0 :-/ Complicating the calculation of the R value of a total wall is the fact that doubling the thickness of a material does not necessarily double its R-value.
I don't see how it can be said that R1 = no insulation, or that R100 would be equal to 1% of R1. I don't understand where that comes from? Help!
Anyone??
From Finehomebuilding.com
R-value
Created as a way to sell insulation, R-value is a measure of resistance to heat flow. The higher the number, the greater the insulating value.
Because doubling the R-value cuts heat loss in half, adding R-1 to R-1 will make a big difference; but adding R-1 to R-30 will reduce heat loss by only about 3%......
http://www.taunton.com/finehomebuilding/how-to/articles/thermal-resistance-ratings.aspx?nterms=65826
If you have an R-2 wall, basically an uninsulated 2x4 frame with just the air films and materials, then adding R-11 batts will only let about 1/5 the heat through the wall. A five fold increase in efficiency. Very cost effective! If you were paying $10 per 100 sf of wall for heating you have now reduced that to $2.00 - an $8.00 saving.
With that R-11 wall you can cut the heat flow through the wall in half by putting two inches of isocyanurate insulation (blueboard or pinkboard) on the inside or outside. This will add an R-10 and cut the heat loss through the framing. This will be cost effective in cold climates and where heat is expensive. It may also be cost effective in very hot climates where electric costs are high. You have reduced your cost of heating from $2 to $1 saving $1.00 per 100 sf of wall by doing this.
If you want to cut the heat loss of the above wall in half again - then you have to add another R-20 to R-25 to the mix. Very difficult to do and not cost effective in most climates (perhaps in the Antarctic ;)). For all this additional work and expense the savings are only $0.50 per 100 sf of wall. You can quickly see that the law of diminishing returns is at play!
I guess what is confusing is the fact that the air film around the building envelope both inside and out has an R value of about 1 so even with no inulation you have R-1. Add a single pane of glass R-1 + R-1 for the air to this and you have R-2 cutting the heat flow in half so even with just a single pane of glass you have cut your heat loss by 50%. Each additional doubling of R-value saves you half of the previous doubling as John said so the second doubling is only a 25% improvment over the first and so on. For walls figure into all this that the studs won't have the same R value as the insulation the losses for windows and the fact that the walls don't comprise 100% of the building envelope and you can see that by simply adding 2" (R-6) of fibergass by going from 2x4 to 2x6 walls doesn't really gain you much when the whole picture is considered. The money example John gave says it best I think. When it comes to insulation the more you spend the less you get after a point.
Scott
QuoteBack home I grew up in a neighborhood full of 1 1/2 ti 2 1/2 story houses, stick built with 2x4's Never saw one of them fall down either. They're now 100 years old and for the most part still there, but mostly updated, renovated, ext. foam added, etc. But underneath the same old, same old.
I live in such a stick built house which is still standing after 60 years, mind you in my case, one difference is that the 2x4's used in it were old school lumber. They are full dimension rough cut beauties. At a full 2x4, they are 8 full sqare inches, whereas modern 2x4's are planed down to 1.5x3.5's which @ 5.25 square inches is actually 34% smaller. The cross-sectional area of a modern 2x6 @ a planed down size of 1.5x5.5 is only 8.25 square inches, and therefore comes very close to a full old school 2x4.