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As I Read “A Snug Northern Home” in this month’s issue, I couldn’t help but be puzzled and dismayed.
Here is yet another article that espoused fiberglass and poly. But it didn’t stop there. They added 2×4 strapping over the whole wall! Probably #1 grade old grouth doug-fir. Somehow the airspace gained them 5.2 R value points. Unless they are counting the sheathing, siding and drywall. Counting all those, I still only get 25.1! I imagine the real-wall R value to be closer to 17, but that is an amateur’s guess.
Then there is the issue of the radiant tubing being installed wrong.
Not one of these articles ever includes blower door tests.
Then they are proud of the fact that it will cost $450 per year to heat. My old, drafty, half gutted house only cost me $500-$600 to heat to 68 degrees this past winter. If you are going to do all this crazy stuff at least halve my bill!!
When will they do an article on DP cells?
Apparently FHB really means “Heavy Home Building” because this wall used double the lumber of most other standard walls. Not to mention the fact that it uses 4 times the lumber of Gene’s wall with none of the bothersome R-value.
Anyone else care to comment?
-Rob
Replies
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Rob,
I was unimpressed and dissapointed too. From the index, I was expecting something fun but I might as well have read Arch. Digest. My storage shed is more energy and rescource efficent than that house (a true total wall R value of R28+). $450 would heat my house till 2006 if the fuel oil wouldn't go bad in the tank.
Ron
*Sooooo ... when is Gene or Fred going to write an entire article? Complete with cross-references to othe FHB articles?The 2x4 strapping was particularly extravagant. Those poor trees.The guy on the cover -- is he risking a nail in his wrist? Or am I too timid. Compare to "DON'T DO THIS!" on page 81.Sean, there should be a special discussion group: Criticize the Most Recent FHB Issue.
*Dear Rob, Ron and AndrewThe Fine House Building name refers to quality building ideas, not Flimsy House Building.You guys must have trouble doing your work with your shorts in a knot, all the time.So some guy builds a house to his liking and you guys stand in judgement of his efforts. Strange how your so quick to defend Gene and FredL when they try to change the way things are built so that they can profit.Get a life boys. Spend a bit of your energy constructively. If you think you have a house design that would benefit mankind, build it, record it and then write an article about it. If it's good and of interest, I'm sure that FHB will print it and I might even enjoy reading it.Gabe
*>>If you think you have a house design that would benefit mankind, build it, record it and then write an article about it.<<I couldn't have said it better myself, Gabe. That's what Gene's been doing for years, only to be roundly boxed about the ears and called a liar.Ron has done some interesting building including fairly elaborate testing that he's detailed here. I would love to see something in print on his projects.I've done nothing but conventional building to date, some I'm not so quick to condemn it, though I'm always looking for better ways. I plan to build a shop using some of the techniques that we all argue so vehemently about and do some detailed recording of its actual performance. Maybe I'll try to write an article about it when I'm done. Talk to me in a few years.I do feel the article in question, though interesting, is incomplete. I would like to see documentation of actual energy performance when they do articles like this, so that people can weigh whether the proposed solutions are worth the effort.Cheers,StevePS: I was glad to see the article on building roofs for snowy climates at least acknowledge the concept of a well insulated "warm" roof for preventing ice dams in addition to the time-worn "cold" roof approach.
*Hi SteveGene doesn't build to help mankind, he builds to help Gene. Therefore he has no credibility. Major point.We all investigate products in order to learn and build better. The first rule is that what works in one area, doesn't always work everywhere. Remember when I told you about dryrot? The wood on both sides are exactly 5 years old. See the difference between the sunny side and the shaded side. Same construction, both sides.Gabe
*Gabe,I stand in judgement only because I have not done much building in my life, and have never bragged about my work, and never had an article published about it. Yet I still have built better insulated structures with better installed function and details. All they did was use R-19 insulation and then add material and cost to the inside of the house with marginal return. The added labor of the 2x strapping may have been better spent with meticulous fg install, or perhaps upgrading to AR drywall. I will give points for keeping wiring inside the air barrier.What is your opinion of the stated Rvalue for the wall.Do you have information about Gene that I do not? If he were truly "profit motivated" he would have taken the money I offered to pay him 8 months ago on this board.Again Gabe - please - share with us your beliefs on the wall system stated. Do you believe any of it to be overkill, an unneccessary expense,or of questionable return? Do you believe the 2x strapping helped structurally? Would 1/2" interior CDX been better for added structural integrity and an air barrier for what I estimate would be the same money? Care to comment on the "correct" installation of the radiant tubing?Steve - please E-mil me so I can get a correct IP address from it. Our network crapped itself and doesn't know how to get them anymore.Do you consider me to be judgemental?-Rob
*Hi RobThe wall has material overkill. Money was used for materials that didn't add value or benefits.I don't comment too much on proceedures to install radiant tubing because I'm not sure that it works in our area that well. Too many homes with open spaces that are a nightmare to make cosy warm without great expense and creative heating and air controls.The thermal value of the walls are in question. I put more emphasis on the doors and windows of the wall systems and really do a number on the roof with regards to insulation.And lastly, yes you are judgemental, but then again, so am I.Gabe
*Gabe,For the life of me I don't know why you are so hard on Gene. I don't build to help mankind either. I build to make a living doing something that I genuinely enjoy.As to your rot example, I still attribute the failure of that particular example to:a) a leak that allowed one or both sides to get wet (which you've corroborated).in conjunction with:b) poly trapping the moisture in wall once it had gotten breached (which we disagree on).From what you've told and shown about the example, I believe that the sunny side was able to cook the water out in spite of the poly, while on the shady side it stayed damp. It might have had a chance to dry out without the poly (or it might not have).By the way, I was unable to download your attatchment, as Netscape doesn't make a plug-in for the Mac tha will handle what you've attatched. Can you attach it as a regular old JPEG image?Steve
*Just a note Steve,,I never collaborated on water leaking into that corner. On the contrary, the entire structure was super sealed. The damage contained therein was as a result of double sealing a wall. What you are looking at is damaged 2x8s that was exposed after removing one layer of particle board that was caulked sealed and one layer of poly.The exterior of the building was also double sealed.Gabe
*There is an important difference between attacking the messenger and attacking the message. I'm really only interested in the messages here.One also need not be personally better at something to criticize someone else. i would be hard pressed to get a basketball through a hoop but I could still tell when Michael Jordan was on or off his game. The "cozy house" article left me with many concerns.
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Joseph Fusco View Image
*If you look back in the archives you will find that Gene has quoted test results from Oak Ridge Lab (ORNL ?) on 2x4 and 2x6 f/g wall assemblies which put the boots to 2x6 walls, and has bemoaned the fact that no one had come up with funding to make comparisons with similar DP cel, or spray PUR. walls. . . then there followed the argument thati lab testresults don't adequately compare to real world applications, or i whole wall assemblies,so we are left with still needing two or three 'identical' houses to be built side by side, with different insulation and framing styles to be used as test subjects, and until such an experiment is conducted we will never conclusively know. Until then we can either take the word of Gene and others who publish tech data and construction specs and make our own comparisons. . . or continue pisssing in the wind with this never ending discussion.I have tried to get technical info out of the Saskatchewan Conservation House people, but they've ignored my emails.-pm
*The doors and windows really are hte key to energy savings. It's sad that the best glazings are R-6 and yet walls can be R-50 with ease.-Rob
*I know the PUR cost $6 psf of wall. This number scared me at first, but then when you consider that it is an installed cost for the insulation, vapor barrier, air barrier, and structural re-inforcing of 2# foam it doesn't seem too bad.Anyone know of a site for information on whipped concrete?-Rob
*Gabe,I wasn't accusing you of collaborating, only corrobarating (sp?) ;-)It's my recollection that you said water had gotten in due to exterior leakage.However it got there, we agree it was trapped.I postulate that the sunny side was able to dry in spite of the poly and the shadey side was not, possibly because of the poly.I think the poly did more harm than good.What do you think?(Not sure why we're rehashing this...)Steve
*What is "PUR"? - thanks - yb
*I just got a bid for 1" of spray PUR in the exterior walls and rim joists for about $0.75 per square ft of wall space in Wisconsin ($2350 for about 3100 sq ft of wall space). I will fill the rest of the cavity with fiberglass.
*As far as whipped concrete...go to yahoo.com and search for whipped concrete...Good Luck!!
*Hi SteveBy having the wall sealed on both sides with poly etc. the moisture trapped on the inside during construction created the damage that you see in the photo. The owner did the work himself and wanted to make it better and tighter than everyone else was doing.The idea worked for 99% of the area, however let's not forget what it did to the other 1%. As is most modern house construction, very few hard procedures can be used absolutely everywhere on earth with the same effects.As far as I'm concerned there is no diference between this method of construction and using EPS and sealing it on the outside of the wall system or the dense packing of celulose inside a wall cavity. The common denominator is not allowing the wall's interior to breath.Gabe
*DP cellulose and double layers of poly behave exactly differently. In fact THE LAST TIME this came up I illustrated how dp cellulose in an enclosed cavity clearly lowers the moisture percentage in the wall. This is crap - forget it, I don't care, say what you like about the stupid picture
*Whoa there RobChill out! You didn't illustrate anything, you stated a theory. You sound like you missed out on your kindergarden time.Gabe
*Rob,
Joseph FuscoView Image
*Gabe,You been skippin' the medication again there, boy?
*Good afternoon Barry,Ya, every once in a while, I grab the wrong glass er vial.Gabe
*I believe Gene said PUR (polyurethane foam) was R 7.3 or so per inch v. fg/dp 3.5. Plus that is a zero convection/air leakage figure, which or course fg doesn't provide.There is probably some latitude when the enenrgy savings balances out the extra cost.
*Hi Andrew,Here are some common R ratings.Extruded blue polystyrene is between 4.3 and 5 per inch. Polyurethane slabs go to 6 per inch. Cellulose is (2.1 to 2.3 lbs density) 3.5 to 3.7 per inch. Fg is 2.9 to 4 per inch.Common wood shavings is 2.4 per inch.Gabe
*For what it's worth from PIMA, the polyiso trade group (note their remarkable inability to spell):View Image
*They also seem to have some errors in R values as well: Xps and EPS are both exaggerated by at least 1 R value.-pm
*Rob, et al. My goal in abandoning the double wall was to find a high R wall that had the positives of the double and single walls but none of their negatives: extremely little conduction through the studs and less labor and material costs. The major negative of the double wall is the substantial costs it adds to a house. Spray-in polyisocyanurate (PUR)is not the only spray-in foam.But with the possible exception of spray-in Phenolic foam--it has the highest R-value of available foams. Thus in a six-inch wall we could achive an R-42. ONRL has never tested a staggered stud wall insulated with PUR. High density PUR allows one to (a) frame studs in the weak direction; (2)eliminate the labor intense cutting, fitting and sealing of RFBI on the exterior of interior of the joist headers;(c)eliminates the caulking of the joist headers to the sill plate; (d)eliminates the labor intense air/vapor retarder;(e)creates a high R wall wihout having to increase or decrease the house size. Now getaway from 11th commandment framing (how does eliminating cripples or headers in non-load bearing walls, 'cheapen' a house?)and the lumber and time savings more than offset the initial high cost of sprayed-in PUR.GeneL.
*Gene, would you spray PUR into a cathedral ceiling? I know you use cellulose in attics, but the cathedral ceiling is more like a wall structurally.
*AMEN Mr Fusco!
*Hi Gabe,We both agree that the moisture being trapped inside was the root of the problem.I disagree that this instance is no different the DP cells wall. A DP cells wall is a different animal. It has the distinct advantage of stopping the migration of air-borne moisture into the wall (which is the major source of moisture in a properly weather-detailed wall). The much smaller amounts of diffusion-driven moisture can dry via diffusion as well if you do not sandwich the cavity between impermeable layers. That's the theory anyway. I believe it enough to start building this way.I don't know enough about EPS to comment.I agree with you that there are no magic bullets, including FG and Poly.Steve
*Hi Steve,It's good that we disagree on a few things. More good things come out of not agreeing with everything any one person says. That's what prevents us all from living in caves. That search for the ideal home design.To be quiet honest, I'm not really concerned with house wrap, insulation or even ventilation as a focal point. I sure would like to find a better way to bring natural light into the home with improvements in present day windows though.The one thing thermal images has taught me is that we may be wasting our time looking at wall and roofs.Gabe
*Hi Gabe,Yes, if we could just get that R-30 glazing perfected we could make some progress.Steve
*Hi StevePlaying with an idea and I'm having a series of windows out of the plant with both exchangeable removable screens and storms that fit on the outside.In the winter, you just open the window, pop off the screen and pop in the storm.We'll be testing this little number this fall and winter. Any comments?Gabe
*Gabe - Is it known how much of the heat loss through windows is through the glass, and how much is through the frame? - yb
*Hi Y. BobWe probably have done less testing on the frames than on the glass. The variety of frames is greater than the types of glazing. Wood is still the benchmark. The heat loss is greater from the glass area than from a well constructed window frame. In a PVC frame, you need air cells and this serves two purposes. One is strenght and the other for thermal breaks.The secret to good thermal resistance in a window installation is in having a good quality heavy frame, well attached to the wall system with continuous nailing strips, silicone caulked and taped. If the window is solidly attached, without air leaks, you've got half the battle won.The idea of using storms can't be overlooked either. The biggest problem in building windows is the weight of the glazing. The thermal panes outweight the frames by mile. The frame hardware will normally fail before the thermal panes will, normally because they are a cause of most failures in the thermal unit. If the frame flexes and doesn't close properly, as it torques it puts a strain on the glazing.So if we can add glazing to the outside, like a storm, we can increase the R-rating without adding weight to the unit and it's hardware.Hope this helpsGabe
*PATRICK. There may be some data coming soon on DP cellulose walls. I'll keep everybody posted.The closest thing to whipped concrete may be Air-Kete which is a cementitious insulation.And to give Gabe more to complain about see page 431, Insulating Concrete, in my book _Complete_Building_Construction_ 4th Edition. GeneL.
*Rob, et al. There is nothing unique about their wall. It is a strapped wall that originated in Scandanavia, worked its way to Alaska, and eventually into the rest of the USA. It is a highly conductive wall because of the strapping to stud direct contact.However, in this instance the conductive path is broken by the 1/2-inch RFBI directly over the studs.The R-19 wall is actually R-13.8 and the 1/2-inch RFBI ups the R-value to R16.8.This could be a potential problem area because it creates an ice box wall--most of you are too young to know about ice boxex-and unless the exterior is air tight moisture problems could result, I'm always leery about claims for dead air spaces because they are rare.For example, what good are foil faced fg batts when the flaps are stapled to the inner faces of the wall studs, and the bottom of the GWB is not sealed to the floor?The wall is unnecessary overkill. The intent of the strpped wall is to keep the so-called air/vapor barrier[sic] out of harms way:wiring is kept out of the VDR by the chases formed by the horizonatl strapping.But depending on the depth of the strapping it could be a NEC violation and a potential shock hazard.Surface Mounted Wiring (SMW) especially the Electrostrip version, eliminates the RFBI, horizontal strapping and much of the wiring. GeneL.
*Air leaks I'm not so concerned about. But I have been thinking about what several folks here have mentioned, that all this debate about batts vrs dp cells vrs bibs - factor in venting, vapor barriers and who knows what all, and you still have 15% (give or take) of your floor space in glazing, which max's out at what, R-6?So now I am trying to remember what the R value is for say a 1+3/8" sash, nevermind the glazing, which I guess could be increased (albeit expensively) with more layers, injected gasses...who knows what all. That leaves the weather sealing around the sash, and the sash itself. Does this question bear study? I don't remember reading anything along these lines. What about thicker sash? In vinal units, what about injecting some type of insulating foam into the cavities? Is this stuff being done? Discussed? And, for what it's worth, I second Stevens appreciation of your "tone" the past week or so. It's inspirational to me to see professionals exchanging ideas, in fact, this forum has renewed my interest in my craft. Thanks for any info or ideas you share. - yb
*Tedd or andrew--I apologise for forgetting-asked if I used or would use spray-in PUR in an attic. My initial reply is No.However,for conventional framing: ceiling below the attic--the attic floor--is full of penetrations from wiring, ductwork and double top plates from partitions, I'd carefully consider a thin sealing layer of PUR, tolled-off with cellulose insulation. Estimate the cost difference between hand sealing all these penetrations and having a thin sealing layer sprayed-in. You may find it too costly given that there may be a minimum charge. because of the small amount of PUR involved.If you use my methods of framing then there is only one penetrtion of the ceiling below the attic: the stack vent, so PUR is unnecessary overkill and costly. Cellulose is the obvious choice.GeneL.
*Y. BobThe sash is minor. You could inject foam at the plant to increase the R factor of the product, but you still require the cell structure of the frame for strenght which causes a thermal bridge.A solid wood frame would be no more detrimental to the overall thermal picture than regular studs would be.At the present time, we have done a lot with the doors but little with the windows. Today's modern home has glass, lots of glass and will stay that way as long as it sells.You can insulate with gold if you want but until you can improve the glazing's thermal resistance you're wasting your time. You can have R 1000 in the walls and R 2000 in the ceiling and the heat loss in winter and heat gain in summer will still be through the windows.Gabe
*Hi Gabe,This is exactly what I am going to do with my windows, but the prime sash are only single-pane 6-over-6 historic windows circa 1865. Midwest Architectural sells an combination screen/storm that is nothing more than an old fashioned wood screen with a rabbet cut intot he inside perimeter to accept a storm insert. I plan to get these, rip off the stationary screening and have screen panels built to sub out for the storms in the summer.I think it would probably be a good thing to do even with double-glazed prime sash.Steve
*Hi Steve,Of course it would be a great thing to do with even a triple pane thermal. Cheapest upgrade on the market.Gabe
*I have asked this question before, but I will ask it again. What is wrong with using poly-isocyanurate insulation on the inside wall, taping the joints with aluminum tape after closing the gaps around windows, outlets, etc. with a can of foam? You get a vapor barrier, and I feel a radiant barrier as well, though someone suggested that unless there was an air space between the drywall and the board that effect would be lost. I don't understand the physics of that idea. I have done this in the past with my office building and have relatively low utility bills given the air-conditioning loads etc. and I am doing it in WI. The only change I would make is to consider blown cellulose with a foil reflective barrier stapled to the studs. I look forward to your thoughtsDennis
*DennisI retro'd the inside of my house just as you suggest, to get more R value out of 2x4 construction that had no previous insul!! Also put f/g in the walls. Blew a lot of the exterior paint off but I don't expect that to happen again. The Celotex Thermax Sheathing that I use advertises R7.2 /inch, but with a 3/4" space behind claims an additional R2.8 = R10/". This "Radiant barrier" actually adds 39%RV if their claims are correct. Have also heard info on this forum that polyiso degrades over time down to R5/" before it stabilises. The additional 'radiant barrier R value' would then become more significant. . . kinda wish I'd used it!!-pm
*Actually, my Q related to a cathedralized ceiling, which I assume can be thought of as a wall with slope? And PUR is polyurethane, right? -- you suggest otherwise above in #11.
*AndrewYa gotta watch Gene, he does that every-once-in-a- while to see if your paying attention. Pur is Polyurthelene, I mean urethane. . . and old girl I new used to call it "that urthelene stuff".-pm
*Let's see if I understand all the smoke so far in this thread. We spend lots of money and effort designing and constructing a perfectly insulated(we think because exactly what affects what and how much is a matter of conjecture if I am to believe the arguments here), air tight house where the occupants live in happy fellowship with all the fumes and vapors of the many glues, paints, fabrics etc in the house.This then reduces their energy cost to truly low level saving humongous amounts of money. Then all the money that was saved on energy, plus some is spent on medical treatments for the homeowners.Looking at the problem from a total cost perspective one must include ALL costs and benefits, not just energy. Concentrating on just energy begs the minimum cost to the homeowner question which is what is important.
*I have to agree with you on the cost. For me, the additional cost of materials seems to be about .30/ft sq, although that is really just a guess as I don't have the cost of materials in front of me. Subjectively, the rooms I have done this way are very comfortable and I am very satisfied that I won't have much of a vapor problem which has been much discussed here. As for the physics, I still am not convinced in that we are really talking about radiation in the infra-red spectrum. A simple experiment would be nice - it might go such.Make a box with two opposite walls one of which has the thermax directly applied to the drywall, and one with a one inch air gap. Place recording thermosistors of the outside of the thermax and measure the temperature differential between the two sides. Since as I understand radiation, it is a function of temperature, this should suffice. As you might know, I am working on a side by side duplex in WI. I have just about completed one side as described above, but you guys have convinced me to go blown cellulose on the other, though I am going to look into the cost of stapling a sort of quilted foil to the studs before I apply the dry wall. All in all, I just like a snug home without drafts.Nice chatting with you and thanks for the comments.Dennis
*FredL. Good to see you back. Forgive the nit picking.I'm in basic agreement with you but a bit uncomfortable with your choice of words.You say, " So it[cellulose] is a true, non-reflective, radiant barrier." Because FG is a poor absorber, radiation passes through it with very little attenuation in intensity. Cellulose, on the other hand, is an adsorber. Now a good adsorber will totally absorb the radiation within a short travel distance, typically less than 2 or 3 microns.It's as though all the radiation were adsorbed at the surface of the material.Where do we draw the line between the true ,ideal absorber: radiant barrier, and cellulose? GeneL
*Please take this lightly as I have always been somewhat interested in this area. But, with that last post my eyes glaze over.Dennis
*Well, i think Gene is just a bit too close to harvard, that's all. Ivory-tower-itis. the only cure is a weekend on the cape.Most of the fiberglas I removed from the wall built by a former homeowner was filthy -- not the way i'd choose to get my fresh air. the fg had even blown into the electrical boxes. the cellulose I replaced it with i am conviced will suffocate any drafts. Truly fresh air will come through the ample gaps in out solid sheathing throughout the uninsulated parts of the house...
*Oh heck....Lets shoot some messengers...it's the way these days....Yes?Near the stream,J
*To all, Okay, for one, I second Dennis's comment "my eyes just glazed over"; and now, the question (i hope i'm not opening up some can of worms buried in the Archives and/or showcasing my ignorance). With everyone talking of insulating the WARM side of the sheating, which arguably still has problems with penetrations and thermal bridging; why not insulate the COLD side. I have never done this or seen it done, but why not put 2" of Extruded Polystrene Foam (as far as I can see, this is referred to as EPS and has a R-value of 5/inch). Masonry would be an ideal exterior finish, but one could also attach furring strips for siding, which would also permit some airflow on the back of your Cedar to aid in drying. Now that I am rolling @ speed, what is the consensus on treating the Tyvek(or your choice of building paper) at the top nailing flange of a window. My limited experience dictates that gravity is the cheapest and most reliable of flashing, so I think one shoule slit the wrap approx. 1" up the header and slide the flange under this flap. Nail it on, and then seal with your tape. Just wonderin'.Jon
*JonYou get an i A,on all points(We put 2"xps up on the exterior all the time)time for you to move on to venting 101.You maybe a little late arriving, but you made up for it. Do check the archives though, you never know, your next synopsis may start another flame war. ;}-pm
*Jon. EPS is Expamded polystyrene, and depending on the type has an R-value of 4 for Type II,and an R-value of R-4.2 for type IX.It is sometimes called MEPS the M meaning Molded. The R-5 per inch you refer to is extruded polystyrene (XPS). In its Blue or light Gray form it is called Styrofoam and this is the trademark of DOW Chemical. GeneL.
*
As I Read "A Snug Northern Home" in this month's issue, I couldn't help but be puzzled and dismayed.
Here is yet another article that espoused fiberglass and poly. But it didn't stop there. They added 2x4 strapping over the whole wall! Probably #1 grade old grouth doug-fir. Somehow the airspace gained them 5.2 R value points. Unless they are counting the sheathing, siding and drywall. Counting all those, I still only get 25.1! I imagine the real-wall R value to be closer to 17, but that is an amateur's guess.
Then there is the issue of the radiant tubing being installed wrong.
Not one of these articles ever includes blower door tests.
Then they are proud of the fact that it will cost $450 per year to heat. My old, drafty, half gutted house only cost me $500-$600 to heat to 68 degrees this past winter. If you are going to do all this crazy stuff at least halve my bill!!
When will they do an article on DP cells?
Apparently FHB really means "Heavy Home Building" because this wall used double the lumber of most other standard walls. Not to mention the fact that it uses 4 times the lumber of Gene's wall with none of the bothersome R-value.
Anyone else care to comment?
-Rob