Replies

1. 
   Hubedube | Jul 20, 2004 04:57pm | #1

   My personal choice would be 2 x 6 -16" oc. for the walls  this eliminates any distortion in the drywall/panelling.  There is no R value difference with a 2 x 6 on 16" and a 2 x 6 on 24"..       6" of insulation thickness whether its 1 foot wide, or 40 feet wide has the SAME R value.   Hube

1. 
   rasconc | Jul 22, 2004 08:02pm | #46

   I could be wrong, but while there is no difference in r-value I believe the thermal transfer for the studs is greater than the insulation.  More studs would make for more transfer one would think.  I did mine with 2x6 16oc with the wet blown cellulose.  I would think the 24oc would be more of a pain for many reasons (sheathing, drywall, angry homeowners years later that have never thought of 24oc, etc).  If the thermal efficiency payout was there the other down sides for the onetime grief of building should not be the deciding factor. 

   Maybe his builder has a ruler marked in 1.25ft increments instead of 1ft.

2. 
   gdavis62 | Jul 20, 2004 04:58pm | #2

   I am here in the hard cold Adirondack mountains of upstate NY.  We design for 50 psf snow load on roofs, and a couple guys I know that build biggies for the rich and famous, do nothing but 24" centers, using 2x6 framing, of course.

   Bear down on your builder and tell him to do it, if you want.  You'll save some lumber, some framing labor (a little), and your exterior walls will be a little better insulated.

   And, all your rafters or trusses will bear directly on studs.

   Tell your guy it is called "thinking outside the box."  And, a lot of commercial floors, and some residential, get framed with joists on 19.2" centers, but that's another story.

1. 
   joeh | Jul 20, 2004 05:44pm | #3

   Shhhh Bob, the Secret of the Red or Black Diamonds is not to be shared.

   Joe H

1. 
   OrchidGuy | Jul 20, 2004 11:29pm | #10

   Come on, everybody knows the secret of the red or black diamonds!

   Those daring young men in their flying machines!

   Edited 7/20/2004 4:31 pm ET by f4phanatic

1. 
   joeh | Jul 21, 2004 12:45am | #11

   Obviously not so or it wouldn't be the subject of conversation at least once a month.

   It's a secret, keep it.

   Joe H

1. 
   OrchidGuy | Jul 21, 2004 03:12am | #13

   I used to work with my neighbor, he explained it to me. Now I know why he said " It's something people should'nt worry about."

   Those daring young men in their flying machines!

2. 
   DANL | Jul 22, 2004 07:24pm | #42

   You can't fool me; there are no such thing as black diamonds--spades and clubs are black, diamonds and hearts are red.  :-)

2. 
   Hubedube | Jul 22, 2004 07:32pm | #44

   Well, I would'nt say everybody knows, but most of us informed people do.  I, personally think this idea of measusuring as far as house bldg, etc is absolutely useless.

1. 
   Sphere | Jul 22, 2004 07:55pm | #45

   exactly right, floating drywall seams with a spline behind it, rack bracing instead of shearwalls, and spray the living bejezus outta it with foam..

   or do as I do, have a log house {G} 

   Spheramid Enterprises Architectural Woodworks

   Repairs, Remodeling, Restorations. 

2. 
   OrchidGuy | Jul 23, 2004 10:31pm | #67

   Measure twice, cut once, but don't measure at all if you can avoid it!

   Norm Abram, from his book Measure Twice, Cut Once. Lessons from a Master Carpenter, 1996

   Those daring young men in their flying machines!

   Edited 7/23/2004 3:34 pm ET by f4phanatic

3. 
   maverick | Jul 20, 2004 05:51pm | #4

   The insulation benefit is so minimal that I would'nt trade it for sturdier, flatter walls AND floors.

   What you are talking about is trading the space of 2 studs in 8 feet of framing for insulation. IMO most averaged sized houses dont have many long runs of wall framing unbroken by doors and windows anyway.

   All your lumber should "stack" meaning framing members should be continuous from foundation to rafter. Add to that your floor framing. Do you really want your floors framed on 24" centers?

   Then you would also need to upgrade your sheathing and drywall to 5/8" and your floor decking to 1".

4. 
   hammer1 | Jul 20, 2004 06:17pm | #5

   It may be a personal thing with your builder. There actually is a small difference in the insulating value between 24 and 16OC. Studs act as a thermal break. Most walls whether 16 or 24 have framing members that relate to each other on a wide variety of spacing. There may only be 1/2" between a stud and a partition lead, the window bucks and door openings are placed everywhere and don't often fall right on your studs. As far as saving money, we are only talking one stud in four feet, so the savings is not huge, maybe a few hundred dollars. The only problem with the 24 spacing is on exterior walls where cabinets will be mounted on the studs only. Many of us use blocking so that is not an issue. If your builder has his mind made up, I would not start arguing unless you are planning to build up to the latest technologies. In that case you will have to educate the builder.

5. 
   BillHartmann | Jul 20, 2004 07:04pm | #6

   If you read betweens the lines of enough messages that have been posted over the years year. More on what is done in different parts of the country,specially by people that have moved, but also cases like years you will see a pattern.

   There is no right or wrong way to do this.

   BUT the real problem is that unless the builder see the benifits and willing to REALLY work with the differneces and ALL of the adjustments (such as blocking) that might be needed that it ends up being a realitvely poor job.

   NOTE - I am not implying that the contractor is careless or any such thing, but when he and all of the workers and subs are expecting do so something one way that unless all of them are on the same page and are willing to do things "differently" then there will be a number of problems that come up.

   All of that said you might do a search on the forum for "mooney walls" and see what he thinks of doing it that way.

1. 
   gdavis62 | Jul 20, 2004 07:32pm | #7

   I worked as a roof cutter in a framing gang that was doing one of these big trophy vacation homes a couple winters ago, and they were doing 2x6 on 24 everywhere, even the interior partition walls.

   Seemed like a no-brainer to me.  The OSB sheathing was 7/16, and the sheetrock was 1/2 on walls, 5/8 on ceilings.

6. 
   DanH | Jul 20, 2004 08:11pm | #8

   Actually, it depends on the waist measurement of the builder.

1. 
   ajm | Jul 20, 2004 11:22pm | #9

   if your worried about the thermal break enough to go to 24"O.C. then why not just have the house built with SIPS?

7. 
   Mongo | Jul 21, 2004 02:46am | #12

   24"oc is perfectly acceptable.

   As to stacking the joists over the studs, sure, it's nice, but with a double top plate on the walls it's not required. Walls can be 24" oc, joists can be 12", 16", 19.2", or 24"...as required.

   To save a few more studs, you can sometimes center the stud spacing off the centerpoint of the exterior wall. This will result in a symetrical stud location along the face of the exterior wall. Doing that, you might then be able to shift the location of the windows a few inches left or right, which will allow you to use a planned 24" oc wall stud as a king stud for a window or door opening.

   There are often ways to save lumber, yet still end up with an aesthetically pleasing and functional layout.

   I do recommend 5/8ths-inch sheetrock on walls with 24" oc framing.

   To further confuse your builder, tell him you want to use blown cellulose insulation instead of FG batts. He'll freak, but you'll get a better house out of it.

1. 
   maverick | Jul 21, 2004 03:21pm | #26

   >>As to stacking the joists over the studs, sure, it's nice, but with a double top plate on the walls it's not required. Walls can be 24" oc, joists can be 12", 16", 19.2", or 24"...as required.

   With that logic you could have stud spacing 24" oc and joist spacing 12" oc with every other joist stacked. Plates are not headers. Kinda takes the F out of FHB.

1. 
   xMikeSmith | Jul 21, 2004 04:12pm | #28

   maverick: to me , it's not fine or unfine... the double top plate eliminates any need or reason to stack your framing... actually... at 24" or 16" OC.. the double top plate does become a "header"

   everyone likes to see stacked framing... and if you are "value engineering" stacked framing will save some framing members.. great if you are Pulte.. not so important if you are doing a one-off custom, or an addition, since there are lots of other things to concern yourself with

   but hey, whadda i no ?Mike Smith   Rhode Island : Design / Build / Repair / Restore

1. 
   maverick | Jul 21, 2004 06:22pm | #30

   >>maverick: to me , it's not fine or unfine... the double top plate eliminates any need or reason to stack your framing... actually... at 24" or 16" OC.. the double top plate does become a "header"

   Try to explain that one to the building inspector

   >>great if you are Pulte..

   Sorry, I don't speak french. What the he11 is "Pulte"?

1. 
   xMikeSmith | Jul 21, 2004 08:22pm | #31

   pulte is biggest homebuilder in the US

   double plate is universally accepted in codes as not requiring stacking of framing

   now , i could be wrong ... but i don't think soMike Smith   Rhode Island : Design / Build / Repair / Restore

2. 
   IMERC | Jul 21, 2004 08:47pm | #32

   Those are the guys that don't put felt under roofing, barrier between sheathing and masonary or use house wrap of any kind...

   Careful... It may become an issue of "Eat dung, 500 jazillion flies can't be wrong"

   Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming....                                                                   WOW!!!   What a Ride!

3. 
   JeffBuck | Jul 22, 2004 03:28am | #35

   "Try to explain that one to the building inspector"

   Uhhh ... the reason why-for a doubled top plate?

   he shoulda learned that on day 2 of inspecting school ... he probably already knows ...

   JeffBuck Construction, llc   Pittsburgh,PA

        Artistry in Carpentry                

2. 
   JohnSprung | Jul 22, 2004 01:20am | #33

   Stacked framing is handy for plumbing and electrical.  If you drill up or down from a wall cavity, you get into a wall cavity on the next floor without having to move the run to clear a joist tail or a stud on the other floor.

   -- J.S.

2. 
   donpapenburg | Jul 22, 2004 06:34am | #38

   With your example ,I think it would be EFHB . The walls would be stacked and the floors would have twice the strength with a joist centered in the stacked bays .  12" oc joist make for a nice stout floor.

   ExtraFine Home Building

3. 
   Mongo | Jul 22, 2004 06:50am | #39

   No it doesn't. I still have an "F".

   Ask around most everyone on this forum will tell you I'm all "F"-ed up.

1. 
   JeffBuck | Jul 23, 2004 05:36am | #59

   "Ask around most everyone on this forum will tell you I'm all "F"-ed up."

   Can't argue that logic!

   JeffBuck Construction, llc   Pittsburgh,PA

        Artistry in Carpentry                

1. 
   xMikeSmith | Jul 23, 2004 05:50am | #60

   mongo.. are you still comming to RF ?Mike Smith   Rhode Island : Design / Build / Repair / Restore

2. 
   Mongo | Jul 23, 2004 05:43pm | #65

   I'm trying...

   August is our vacation time. Usually go "somewhere" plus we spend a week or two up in Maine.

   This year the "somewhere" is Germany, and we're leaving out of JFK for Frankfurt on the 14th.

   I've had ideas about a hit and run visit Saturday morning, but it remains to be seen if the logistics of that will actually work. Rebecca has been talking about spending a couple nights (Weds-Fri nights) in Manhattan before we fly out, so that may negate the Saturday morning visit.

   If you need a hard answer, it's "no". Soft answer? "Maybe". Regardless, if I do make it, the length of stay? "Brief".<g>

   Sounds like it'll be well-attended.

3. 
   xMikeSmith | Jul 23, 2004 11:19pm | #69

   thanks for the update.. and have a great time in Germany...

    sneak by if you canMike Smith   Rhode Island : Design / Build / Repair / Restore

4. 
   Mongo | Jul 26, 2004 08:44pm | #72

   I'll email you the week prior to get an idea of what's going on Fri night/Sat morning. I really want to swing by and have a few laughs, even if it's only for a couple of hours.

5. 
   xMikeSmith | Jul 26, 2004 10:00pm | #73

   sounds like my kinda plan... the more the merrier !.. send me your address so i can mail you the directions

   the rest of you.. if you sent a check..i'm going to mail out the directions.. anyone else , email me with your address and i'll return mail the directionsMike Smith   Rhode Island : Design / Build / Repair / Restore

6. 
   Piffin | Jul 27, 2004 03:53am | #74

   Directions, yeah, Good! that way I won't have to ooze into the state 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

8. 
   TLE | Jul 21, 2004 03:18am | #14

   I'm not sure why you would want to tell the builder how  to do his job.

   I assume you chose him from referals or have some knowledge of his past performance on other homes.

   Either you trust him to provide a quality product built in a manner of his choosing, or find a builder that better suits you.

   Terry

   P.S. I strictly fall in the 16" oc arena.

9. 
   hasbeen | Jul 21, 2004 04:14am | #15

   There isn't anything "wrong" with going 24"  oc, but I wouldn't do it.  The reasons have already been stated by others.

   Surely, someone is going to come along and tell you that you can go 2x4 16"oc and spray foam insulation....  And that's viable, too.

   I'd also suggest dense pack cellulose sprayed into the 2x6 cavities.

   You're unique!  Just like everyone else!      Scott Adams

1. 
   jrdiblumber | Jul 21, 2004 04:42am | #16

   forget cellulose who wants paper in their walls go for sprayed in fiberglass.

1. 
   Sphere | Jul 21, 2004 05:06am | #17

   now ya did it...another insul, fest. 

   Spheramid Enterprises Architectural Woodworks

   Repairs, Remodeling, Restorations. 

1. 
   Piffin | Jul 21, 2004 05:28am | #19

   Here, have a bagel with your insulation

   ;) 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

1. 
   woodbutch777 | Jul 21, 2004 04:01pm | #27

   Thanks for mentioning 2x4 walls and getting the high R value. I build small additions by myself except when I need help lifting 2x6 walls with headers and to much weight. Have you built the 2x4 with double r value and if so how was the cost difference compared to 2x6? Did it balance out the price difference of 2x6 framing , extension jambs ?

   As for the 24" O.C. I did clapboards on one along time ago and the walls had lots of in and outs as well as the fact that they were like a trampoline when nailing off around trim areas even with the H clips on the sheathing. Maybe i am over kill but 16 o c is the way to go and blocking is still used where needed. I cant imagine 24 oc with the vinyl siders following YIKES!!

2. 
   Piffin | Jul 22, 2004 03:26am | #34

   Curent analytical specifics on the whole wall assembly I don't have, but let's think it through -

   If you save one stud in four feet and the typical modest house has 140 LF of exterior wall, that's 35 studs saved. 35 x 8' x .67 = 188 Bd ft saved at say fifty cents/bdft = ninety four dollars by elimination of certain studs, if the window and door layout is fine for it.

   Then you add for the wider remaining studs and all the plate material...the stud cost added balances ot and the plate cost added drives you over the top.

   Now, insulation.

   With batts, you can do up to R15 in a 2x4 wall and R19+ in a 2x6 wall

   urethene foam sprayed in place gives you R7/inch so you can easily get R21 in a 2x4 wall.

   Note that i was carefu l to say that the "effectiveness" of the insulation in a 2x4 wall could be doubled vs. batts

   If you ever study the info from "Walls that Work" there is a lot of refs to convection curents and studies showing that when FG batts allow convection currents in the wall cavity, as the temp approaches zero, the usfull effectiveness of the FG also reaches zero, while the effectiveness of foam is almost the same as at 70° and with BIBBs or Denscellulose, it changes but little.

   Another way to really increase the effectiveness is to apply a thermal break sheet on the inside of the studs. Thermax is about R3.5/inch and doubles as a VB if carefully installed. 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

3. 
   DougU | Jul 22, 2004 04:01am | #36

   Piffin

   Reading your post no. 45544.1 and the one I'm currently responding to reminds me of another Yankee, Norm Abrams. I read his book on building his own house, he said pretty much the same as you did in your two posts.

   He built with 2X4's and on the inside he put that foil faced r-board,(not sure if that's what the stuff is called, its the insulation board that has foil on one side, some builders use it for sheathing, think its about 1/2") then I think he had the spray foam(sorry I don't know these terms, don't come up in the cabinetry world everyday) in the wall cavities, with ply sheathing, or OSB.

   If I recall he said the same as you regarding the 2X4 Vs the 2X6 framing. Made a lot of sense to me. I was convinced that I needed to build with 2X6's until I read his book.

   Doug

4. 
   BillHartmann | Jul 22, 2004 04:11am | #37

   When I built my house in 79 I used looked at that and decided on foam on the outside instead of 2x6's. But then I used FG, not sure what other alternatives in insulation that where commonly available at that time.

   Mine used 3/4 or 5/8's foil faced polyiso insulation. Tuff-R is one common brand at that time made by Celotex, now by Dow.

   But at that time there was not a lots of know about the detailing and I have had some minor water problems.

   If I was going to redo it today I would seriously look at using a mooney wall with dense pack.

5. 
   Piffin | Jul 23, 2004 01:20am | #47

   Thermax is one trade name for the foil faced foam board and it comes in several thicknnesses,. I've bought 1/2", 3/4", 1", and 1-1/2" with no problem.

   I'm glad to know hat Norm is right about something too.

   but don't go starting the runor that he is me, LOL

   There are way too many guys using the Thermax on the outside of the studs in northern heating climates. That is fine in the deep south cooling climate, but in the north, it can trap moisture in the wall cavity and promote mold - tho if combimed with spray oam too, there will be no condensation anyway 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

6. 
   maverick | Jul 27, 2004 04:29am | #75

   >>I'm glad to know hat Norm is right about something too.

   >>but don't go starting the runor that he is me, LOL

   Thats impossible. You can't type with both hands in your pockets

7. 
   Piffin | Jul 27, 2004 05:33am | #76

   There are those who claim that I can't type with both hands out of my pockets 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

8. 
   Piffin | Jul 23, 2004 01:33am | #48

   There is another historical point to be considered in this discussion. Back in the seventies when the idea of 2x65 walls was first popularized, the basic FG batt insulation was rated R-11 and it was possible to buy it for the 3.5" walls at R13.2. now, you can buy dens quilted FG batts rated at R15.

   Denspak cellulose, blown in runs you about R-3 per inch which is only R11, but the effectiveness is far above that of FG batts. The R value is resistance to heat loss as measured in a lab with temps about 70°F on one side of the wall and 45-50° on the other side. which does not grant enougth of a thermal differential to set up a convection current of heat loss through the fibreglass. It primarily measures radiant heat loss is all. 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

9. 
   xMikeSmith | Jul 23, 2004 01:48am | #49

   piffen , my blowing charts use 3.5/inch for blown-in cellulose, this is for a density of 2.2 lb/cf

   most of the dens-pack guys assume 3.8/ inch with a density of 3+ lb./ cf..

   to figure conservatively , i always use the 3.5/inch even though we do get our density of 3.0 lb/cf

   i've done several sample walls and weighed the result.. we've also  exactly measured large cavity jobs and tracked our 26.5 lb.  bag count... we consistently exceed our goal of 3.0 lb/cf..so if the mfr. is publishing  3.5R/inch for a density of 2.2 lb., i'm pretty happy using that for our insulation values

   natch...3.5R x 3.5 stud bay = 12.25 R-value

   if you go with the 3.8R then this stud bay will be 13.3 R..with a mooney wall ( extra 1.5") cross furred i assume a  true net of about R16 allowing for stud loss

   Mike Smith   Rhode Island : Design / Build / Repair / Restore

10. 
    Dinosaur | Jul 23, 2004 03:13am | #51

    Mike--Illuminate me....

    Since theoretically the best insulation possible is a perfect vaccuum, then it seems like 0 pounds per cubic foot would logically give the best R-value.

    Okay, back to the real world. Still and all, seems contralogical that stuffing more paper more densely into a stud bay would increase resistance to heat transfer across that thermal barrier. If it is indeed the case, why aren't we just using solid wood walls? Trees are, after all, made of cellulose in large part....

    I'm not smart-a$$ing (for a change, LOL!); I really want an explanation why more shredded newspaper in a stud bay = less heat loss.

    A semi-related comment on sprayed in cellulose or foam or whatever--It makes future snaking of utilities a destructive exercise, so if you're going to use that sort of insulation,run a few 2½" conduits here and there to avoid that problem.

    As to the original question--16 or 24 centers--Mongo's right IMO. Nothing wrong with stacked framing, but it doesn't buy enough advantage to make it worthwhile bustin' yer head over it.... My objection to 24" centers for the studs has to do with insufficient support for ½" gyprock to refrain from turning into a big drum. Go for 5/8" gyprock now you're adding other problems elsewhere, like jambs that don't come flush.... It's quite true that I routinely frame roofs on 24" centers and do not have problems, but it also requires heavier sheathing than code to make a good job; 5/8 minimum and forget the OSB, use ply.

    And the only black diamonds I deal with are on the ski slopes....Dinosaur

    'Y-a-tu de la justice dans ce maudit monde?

11. 
    Piffin | Jul 23, 2004 03:54am | #54

    Cellulose does have some small amt of cavity space in the cells to contail still air which is one reson the R-vaule of it rates slightly better than BIBBs chopped fibreglas 

     

    Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

12. 
    DanH | Jul 23, 2004 04:16am | #55

    The trick with insulation is to have as much nothing as possible. But air isn't nothing. Air is subject to convection. Nothing isn't. (Note, we're ignoring radiation as a heat-transfer mechanism here. Radiation is not a significant factor in most types of wall construction.)

    Yes, air is probably the best inexpensive insulator you can have, but something must be done to break up convection. That's where conventional insulations come into play. They, one way or another, impede convection so that hot air from one side of the wall doesn't exchange with cold air on the other side.

    The best insulator, given this observation, would be the insulation that isolates the air into many small cavities, with the least amount of cavity wall material possible.

    Fiberglass does a relatively poor job of creating cavities. At best, it impedes the flow of air from one side to the other, but the nature of the fibers is that air can circulate fairly freely -- "leak" between the cavities. Cellulose, since it isn't long, narrow, solid fibers but instead is a very fine matrix permeated with air, creates much smaller cavities and also is better at actually preventing air "leakage" between cavities vs just slowing it down. (Closed-cell foam is "perfect" in preventing "leakage", but the cavities are comparatively large.)

    Given the nature of both fiberglass and cellulose, denser is better, up to a point, since it increases the number of cavities and reduces the "leakage" between them.

    There is, of course, another issue, though its significance varies depending on the style and quality of construction. This issue has to do with how well the insulation prevents infiltration.

    In many cases there is no point in having an insulation value greater than, say, R11, since air infiltration (air from outside getting inside and vice-versa) causes more heat loss than normal conduction through the walls.

    The same characteristics that make cellulose a good insulator (low "leakage") makes it good at preventing infiltration. This is especially true since cellulose, blown or sprayed, will pack around wires, pipes, and other things in the wall that might otherwise facilitate infiltration.

    I would guess that the average mid-1970s R11-walled home has an effective R value, when infiltration is taken into account, of 3-5. This is especially true in windy locations. Clearly, in addition to using a infiltration-unfriendly insulation, using housewrap and carefully caulking can make an enormous difference.

    I've never gone back to look at the numbers in our 1976 home, but I would estimate that, over the years, we've halved the overall heat loss by residing with house wrap, carefully sealing around windows, etc. And, by reducing drafts, the increase in comfort has been even more substantial.

    Note that most of what is true about cellulose, in terms of reducing infiltration, is also true of foam, but cellulose is cheaper and generally easier to deal with. Both accuse the other of settling or shrinking, but it's not clear whether either has this problem when properly applied.

13. 
    xMikeSmith | Jul 23, 2004 05:14am | #57

    great post , dan... well said... and apparently without the bias that i usually exhibit when discussing celluloseMike Smith   Rhode Island : Design / Build / Repair / Restore

14. 
    Piffin | Jul 23, 2004 05:29am | #58

    "we've halved the overall heat loss by residing with house wrap, carefully sealing around windows, etc."

    I still rememeber the first tiome I used a house wrap. It was on another isleand near here, doing a fairly large addition to a house that people were living in. We got it closed in just before Thanksgiving and after taht, we wrkred inside on the poor weather days and outside when the sun made us welcome.

    The NW Wind blew incessantly bring a lot of frigidity along with it so Inoticed instantly almost, that the interior temp had risen about ten dreees beyond what the normal ( or exterior)

    was. 

     

    Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

15. 
    Dinosaur | Jul 23, 2004 05:50am | #61

    Ditto Mike's comment, Dan. Very informative post. I knew a lot of the basic theory, but you put the application into perspective.

    I still have issues with cellulose and urethane foam, some of which are ordinary practical ones (as I said earlier, they make a renovator's life more complicated), and some of which strike at the heart of the philosophy (you knew I'd get to that! LOL) of living in a TSB--Totally Sealed Box.

    Our building code has required air exchangers on all new construction for quite a few years now. This is to deal with the problems created by modern building technology's ability to isolate completely the inside of the house from the rest of the world. Among these problems are such phenomena as condensation, accumution of odors related to living(cooking, smoking, farting, etc.), and semi-ærobic mould propagation--the sum of which problems is sometimes referred to as 'Sick Building Syndrome'.

    The first house I ever built was my own. I didn't plan a lot of the details in advance, not having past experience to guide me, but instead asked a lot of questions of old timers, materials sales people, and subcontractors as I got to each new stage of construction. When I got to the insulation, I knew from having consulted with my BIL--a high-end custom house builder in Ohio--that standard wisdom dictated housewrap, sheathing, insulation batts, poly film, and gyprock, in that order, from outside in.

    But an old GC I had doing the excavation for me told me no. 'Don't use that plastic sheeting as your vapour barrier', he said. 'The house'll be so tight it won't be able to breathe at all and it'll stink all winter like the inside of an old gym shoe. Use the old foil-backed kraft paper instead. That'll seal well enough against moisture to keep your wall cavities dry, but it'll let in enough fresh air so you won't choke on your own exhaust....' Sort of like Gore-Tex for houses, I thought.

    I did it his way--and he was right.

    Would my Hydro bill be lower if I'd used the polyethylene? Possibly, but since I heat primarily with wood it wouldn't be much. Would I use less wood? One less log per night? Maybe.

    Which begs the question: 'Would it be worth it?'

    My grandmother always slept with a window cracked open an inch or so, even in the coldest weather.

    She lived to be 100.

    What do you think...?Dinosaur

    'Y-a-tu de la justice dans ce maudit monde?

16. 
    Mongo | Jul 23, 2004 05:29pm | #64

    Nice words Dan.

    And that reinforces the thing that the average person just doesn't fathom regarding R-value.

    Effective R-value

    You can insulate all you want, but as long as the wind whistles through the insulation the insulations just isn't insulating.

    RFBI and dp cells are the way to go.

17. 
    DanH | Jul 23, 2004 08:58pm | #66

    One thing that amazed me is the difference it made when I pulled off the window trim and filled the RO gap with low-expansion foam. I'd always assumed that the cold air around the windows in the winter was leaking through the frame/sash joint or just conducting through the glass, but filling that gap made a world of difference. And we already had resided (tempered Masonite) with Tyvek and very careful caulking.

    Gotta give my wife credit for forcing me to try this, though.

18. 
    Mongo | Jul 23, 2004 05:25pm | #63

    Using 5/8ths rock can present a problem...unless you do as I do, and embrace said problem...

    First, if you have to make jamb extensions, adding another 1/8th to the depth is no extra work at all.

    If you order the windows/doors with factory jambs, then the 1/8th can be a pain. All I do is when trimming is picture frame the jamb face with a 3/16ths or so rip or wood to bring the depth back where it belongs. I step it back a tad, then when trimming, again step the window trim back again off the face of the 3/16ths rip.

    It creates additional shadow lines, adds a bit of visual detail...and only adds a minute or so to the trim sequence.

    You're right though...in construction, when it comes to saving wood or saving time, it brings back that old saying that guy Newton used to preach about..."For every action, there is an equal and opposite reaction..."

     

19. 
    Dinosaur | Jul 24, 2004 02:21am | #70

    Sir Isaac did have a way with words, didn't he?

    I wonder if he also wrote Murphy's Law under a pseudonym...?Dinosaur

    'Y-a-tu de la justice dans ce maudit monde?

20. 
    gdavis62 | Jul 24, 2004 03:25am | #71

    This started as a 16 versus 24 discussion.  Did you all see the sawn lumber spike that just occured?  For me, #2 spruce framing lumber jumped 20 percent in the last ten days.

    24 might be looking veddy veddy good to me, if this continues.

21. 
    JohnSprung | Jul 23, 2004 10:46pm | #68

    > seems contralogical that stuffing more paper more densely into a stud bay would increase resistance to heat transfer across that thermal barrier.

    There are two things going on as you stuff more cellulose into the cavity.  1.  You're making the tiny air spaces even smaller, which reduces convection and improves resistance to heat transfer.  2.  You're bridging between the inside and outside with solid stuff, thereby increasing the path for heat to move over. 

    When you start from very little material in the wall and increase the amount, the first effect does more good than the second does harm.  If you had the stud bay stuffed nearly as full as if it were solid wood, the second effect would win out over the first, and more material would make things worse. 

    Somewhere in between there must be a crossover point where you get the maximum R value per inch.  As a practical matter, it seems likely that that crossover point of maximum insulation is beyond our ability to cram stuff into the wall -- or to do so without damaging the sheetrock.

    -- J.S.

22. 
    Piffin | Jul 23, 2004 03:44am | #52

    OK, so I was off a mite on the detail, but the point is that I would rather have R-11 or r-15 or whatever from blown than to have a theoretical R-15 from fibreglass batts 

     

    Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

23. 
    xMikeSmith | Jul 23, 2004 05:12am | #56

    i knew datMike Smith   Rhode Island : Design / Build / Repair / Restore

24. 
    JohnSprung | Jul 23, 2004 03:13am | #50

    > The R value is resistance to heat loss as measured in a lab with temps about 70°F on one side of the wall and 45-50° on the other side.

    Those tests might not be valid for you in cold country, but for us in Southern CA, they correspond pretty well to actual winter overnight lows.  So maybe in LA, FG is OK?  ;-)

    -- J.S.

25. 
    Piffin | Jul 23, 2004 03:49am | #53

    LOL, sure, have fun with it. Somebody has to keep subsidizing the worst insulation product on the market! besides, it can vent the heat out through it

    ;)

    Actually, I would assume your bigger concern out there would be radiant barriers to keep the heat out. 

     

    Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

10. 
    Piffin | Jul 21, 2004 05:23am | #18

    If the builder is otherwise reputable and has reasons for5 the 2x4 walls, don't waste your time making it an issue.

    There are two main resons given by proponents of the 2x6 wall system which came into popularity briefly in the so-called energy crisis of the seventies. both advantages has since been demonstrated to be fallacious assumptions - at least in the minds of those of us who have done it both ways.

    First assumption is that you can have better insulation because of the extra 1.75 inches of fibreglass thickness. building science has come along so far in the last thirty years that we can show you half a dozen other, better ways to increase your insulation values in the 2x4 wall than to use the 2x6s. If the goal is better insulation, you want to immediately stop thinking about using the absolute least efficient kind of insulation available - fibreglas batts, and start thinking in terms of BIBBs, Denspak cells, or foams or a combination. It is easy to double the effectiveness of the insulation in 2x4 wals over batts in 2x6 walls. Yes, that's right, double it.

    Second is that the 2x6 will save money on lumber. If I were your builder and you wanted this savings, I would promptly end the discussion by writing you a check for the calculated "savings" to convince you to let me build the better house.

    See, when you use 2x6 framing, you might ( Might because it all depends on location of openninngs in the walls) save a few bucks on theframing lumber, but you have to turn it around and spend it again on more blocking for cabinets and to maintain straight wallboard and siding. You have to spend it again on window and door extension jambs. You have to spend it again on extra concrete for the foundation, because to have the same interior space, you need a bigger box to fit it into. I believe that from my experience, there is absolutely no real cost savings for a house built from 2x6 instead of 2x4. It only shows up in theroy on the perfectly shaped house with an ideal arrangement of windows and doors.

    Houses, however, are build to house humans, humans are not born for the purpose if fitting into certain sized houses that were designed to save a buck.

    so, If I were your builder, I would explain these things to you and then build whatever you wanted, within reason. But I would be considering the possibility that this idea of yours is the tip of the iceberg where you might plan to be telling me too much about how to build. Most past customers who did that were wrong nine times out of ten

     

     

    Welcome to the
    Taunton University of Knowledge FHB Campus at Breaktime.
     where ...
    Excellence is its own reward!

1. 
   ajm | Jul 21, 2004 05:32am | #20

   "All praise Piffin, wise and powerful Piffin" I agree totally with your post. I built mine 2x4 with skim coat urathane foam in the cavities filled the rest of the way with dense pack cellulose. absolutely no complaints. If you are trying to save heating and cooling dollars, I reccommend looking at geothermal saves me a shatload of money each and every month. and no fear or carbon monoxide to boot.

2. 
   BillHartmann | Jul 21, 2004 06:33am | #21

   Good answer!

   Unfortuenatley for the wrong question.

   Apparently it is going to be 2x6 construction.

   The question is 16 or 24" spacing.

1. 
   Piffin | Jul 21, 2004 07:52am | #24

   Actually, if you want to get technical, the Q was "is this a regional thing" to which I would answer, "No, it ios an experience thing"

   But life can be good either way if he frames @ 16" OC 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

1. 
   DanH | Jul 21, 2004 04:45pm | #29

   I still say that the primary determining factor is the girth of the builder.

3. 
   mediarich | Jul 21, 2004 07:49am | #23

   Thanks everyone for the posts and the wealth of information.  I tend toward 2 x 6 for aesthetic reasons, but I'm now sold on the 16" spacing. 

1. 
   JeffBuck | Jul 21, 2004 09:18am | #25

   so now you going to do 16oc and 5/8th drywall?

   more is gooder ...

   JeffBuck Construction, llc   Pittsburgh,PA

        Artistry in Carpentry                

4. 
   DANL | Jul 22, 2004 07:30pm | #43

   What you said about houses being for human beings is so true--remember when dome houses were the rage (enclose the most volume with the least surface area, bla, bla, bla...)? The people found out, hey, furniture tends to have flat faces and edges and all this extra volume got wasted. 

11. 
    jonblakemore | Jul 21, 2004 07:41am | #22

    If you primary purpose is insulation value do a BT search for "mooney wall". It might not be something that your builder would go along with, but you will learn a lot.

    I probably would not space at 24".

     

    Jon Blakemore

12. 
    Schelling | Jul 22, 2004 01:11pm | #40

    It should be obvious from the responses that you have had that all these points are debatable by the experts here. You can either tell your builder exactly how to build your house or you can let him decide how to do it. If you have a complete set of plans from an architect, you have made that decision and the builder should simply follow the plans unless he sees an obvious omission. If you are using the builder to fill in a lot of uncertain areas, the two of you will have to hash it out. The quality of your house will not be determined by whether you use 24 oc or 16 oc, but by the care that is taken by the builder and all his subs. Anything that you can do to facilitate this, you should do including listening to what the builder's experience has to say.

1. 
   mediarich | Jul 22, 2004 04:30pm | #41

   My sense is to trust his judgment, but I also want to make sure his philosophy is similar to mine - I'm not necessarily interested in all the technical aspects of his business, but I do want a builder who's openminded and willing to consider alternatives to the "common" approach.  Respectfully, I find that many in my area who bill themselves as "custom" home builders are just building bigger, more expensive homes. 

   When I read FHB or peruse this forum, I see (and hear) folks who are genuinely interested, ambitious and passionate for their craft.  I'm sure there's a little bit of "grass is greener on the other side..." in my perception, but I'm envious of this.  My personal search for a builder has yielded nice, professional folks - but no one who seems really excited about building a home. 

   These comments are tangential to the 16 oc vs 24 oc thread, but shouldn't I have a reasonable expectation that a good builder would at least discuss the pros and cons of various options rather than just rolling his eyeballs and saying "no?" 

   Edited 7/22/2004 9:31 am ET by mediarich

1. 
   Schelling | Jul 23, 2004 05:53am | #62

    " My personal search for a builder has yielded nice, professional folks - but no one who seems really excited about building a home.  "

   You may be expecting a little too much. There are a lot of good builders who have done a lot of building and your house is just one more.  If you are willing to try someone with a lot less experience, you may find someone who is excited about building a home and trying new techniques just for the fun of it. I know I was a lot more like that twenty years ago. Of course now I can build a better house but I have a lot less patience and enthusiasm. You can choose that young excited builder or you can get an old pro whose respect and friendship you will have to earn over the course of the construction. Both types of builders have their strengths and you just need to decide with whom you will be more comfortable.