*
Hey Gabe,
If you’re so popular then why did you only get 300 out of a possible 15,000 votes in our last mayoral election. Just curious.
Brian
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Skim-coating with joint compound covers texture, renews old drywall and plaster, and leaves smooth surfaces ready to paint.
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
*
Why all the fuss about airtight ceilings? I believe that if all the drywall joints and corners are properly taped and that wall and ceiling penetrations are sealed, the ceilings (and walls) would be essentially air tight. However, I would NOT say that they are water tight (vapor). Drywall passes moisture readily. Even latex primer and paint are not true vapor barriers. Shellac based primers are though.
A friend of mine just built a house that is Energy Star Compliant. The house is of typical modular construction. A blower test was conducted after construction that showed no measurable air infiltration into the structure! However he does have a fresh air inlet with a heat exchanger attached to his forced hot air system. If operated properly and the filters maintained regularly, the system should keep the house from developing moisture and mildue problems in the future.
My point is... When do we go too far. Houses are becoming so air tight that we have to add systems that bring fresh air into the house. These systems use alot of energy themselves to operate (1500 Watts +/-). I haven't done the calculations but it appears that you end up spending money to save money.
The whole thing appears to become an academic exersise to see if true airtightness can occur in residential construction.
*
Thanks for the reply Fred.
The discussion on truss uplift some time ago has me wondering about firmly attaching the top plate to the trusses (or blocks attached to trusses). I could provide a means to anchor top plate using long shank screws in a predrilled plate which would allow some vertical motion, but then what about the gaps that might form. Does there exist a J channel which could be anchored to ceiling with the wall drywall "floating" in it at the top? Or should I not worry about it and anchor the dickens out of the top plate? Thanks again.
SteveW
*Gabe. Based on a number of your previous comments on building inspectors, I'm surprised to learn you allow them on your building sites.I've had little trouble with building inspectors or with the subtrades. To prevent trouble and Stop Work Orders, I always requested a pre-framing conference with the official, and with the pumbing and electrical inspectors. I never had one building inspector tell me I couldn't use the 2x3 staggered stud wall, or an electrical inspector tell me I had to install duplex outlets in a wall. Lead framer is told about, anong other things, GWB air retarder being installed first and then partitions. Because of the elimination of wiring, plumbing, ductwork in exterior walls and in the ceiling below the attic, the exterior wall GWB is installed immediately after the framing inspection.But first we ask the building official if he must see the insulation completely installed, and what we can do to assure him the cavities are fully insulated. Of course, the ceiling below the attic can be rocked immediately.The building official can observe the cellulose installation from tha access hatch, which, by the bye is not located in the house. With sprayed-in PUR this is not a problem. Yes, I have had sheetrockers tell me where to go when I mentioned 2-stud corners and Prest-On clips.But I also found some who would listen as I explaind the why of the clips and how they benefitted by using them.All this can be done on custome houses but not with track house, it is claimed. Really? GeneL.
*MDuval. The seeming excessive concern with air tightness is just that, seeming. But given that 40% of a house's heat loss is due to leakage, and given that we now know that air leakage is the real cause of moisture damage, stopping this leakage is top priority. Alas, air sealing packages add between $500.00 to $1000.00 to the cost of a house. How do the sealing but avoid the added costs? By rethinking framing and scheduling we can eliminate most of the sealing with caulks and foams.For example,putting the outside wall down on the sill plate breaks the conductive path between the wall and the platform. Sealing the bottom wall plates to the subfloor is unnecessary as is the abor intense cutting and fitting of rigid foam board insulation(RFBI)to the exterior or interior of the joist headers.The joist header gets insulated and sealed with cellulose insulation at the same time the exterior wall is insulated.The roof is trussed thus eliminating interior load bearing partitions. Because all wiring, plumbing, ductwork is eliminated in exterior walls and from the ceiling below the attic--attic floor--the ceiling Gypsum Wall Board (GWB)is installed in the longest length obtainable to minimise butts and joints. No vapor barrier--vapor diffusion retarder (VDR) is necessary. NOTE: we are not looking for a "true" vapor barrier. And we don't care if the VDR has a few holes, rips or tears. The effectiveness of a VDR is a function of its area. If 90% of the area of the VDR is intact, the VDR is 90% effective.The small amount of moisture moved by diffusion(diffusion does not move large amounts of moisture quickly) is easily controlled with a VDR paint. Air leakage will move 100 times more water vapor through a 1 inch hole than will vapor diffussion. The integrity of the GWB air retarder is what concerns us. The installation of the GWB first give us a thermal break between the top plates and the bottom chords, and minimises the possibility of truss uplift. The caulks, foams and gaskets needed to seal the top plates are unnecessary. GeneL.
*Hi Gene,Never said I had a problem with them, what I said was that you would have had a problem on one of my sites with your burning desire to rewrite the construction industry.I'm the first to encourage others to seek out the advice of the building inspectors in their respective jurisdictions.I'm also the first to encourage others to seek out substantiated information at the various sites and not rely on your "book" for real world information.I also use less words to convey my feelings about your advice and your "book" than you do to say nothing.Gabe
*I have walked the walk, however only on projects up to 21 million dollars. The largest single construction project I ran was 3.1 million. You always present deviations from the norm as rigid, and difficult. In my meager experience, this has not been the case. Perhaps because I have specifically never been involved in shotgun scheduling (more generic than "Production Building"). If it has to be a certain way when it is done, then you need willing partners along the way. I am not saying the path is worry free, or smooth as silk. But it is usually worth the effort. On a Water Treatment plant we did, I damn near ran the wet saw!! The masonry facade had three different materials with two different mortar colors. An incredible pain in the ass, you bet. But gorgeous when done such that the masons were even impressed when they were done. They were entirely resentful and pissed when they started the thing.Sorry I haven't walked YOUR walk, but thus far my experience is vastly different from yours.What is your opinion on how the state of the residential construction industry would be if banks weren't involved, schedules could be relaxed, and consumers were better educated? Do you think the benefits would outweigh the costs?-Rob
*Hi Rob,First thing first,there is absolutely no difference in running a 3.1 million dollar site or a 31 million dollar site. If anything, I find the 31 million dollar site easier.As a manager, you don't have time to teach. You depend on the quality of the workers, subs and suppliers that you have contracted. If you know your work, you also know how to surround yourself with the best.As to my opinion about the state of residential construction would be if banks weren't involved, schedules could be relaxed and the consumer were better educated?Simple, the banks aren't involved as we speak other than in the business of making loans and making money. Because money is tight, so are schedules, because time is money.The last point, the consumer had better educate himself because no one is going to do it for him. I find the average is far more knowledgeable than the consumer of 10 years ago. But still has a way to go. It is more difficult today to sort information as to it's accuracy. So buyer beware.In closing, your project was a water treatment plant, not the White House. Any architect that would specify 3 kinds of masonry for a facade of a water treatment plant should be put in jail for being instrumental in the misappropriation of tax dollars.Gabe
*
Joe Fusco. I'm not certain I understand your question on the seamless ceiling. I am not looking for a seamless ceiling and do not believe I used that term. The ideal ceiling diffusion retarder, like the ideal roof has no penetrations. I always talk about as penetration free a ceiling air retarder as possible. The only penetrafion being the stack vent.
Now a an air retarder is not just a piece of material, but an assembly, a system. Any material or system may be used as an air retarder ikf the following 5 criteria are met. I'll list only the first of the five.
All the various parts of the air retarder system must be joined together so that the system is continuous and unbroken throughout the structure. Although the air retarder could be located within the exterior wall, in residential construction the gypsum board serves this purpose.
Thus does the mud and taping serve the purpose of continuity of the separate parts. We would ignore any moisture movement by diffusion. Such movement is controlled by the painting of the air retarder GWB. But become concerned at the slightest air leakage. Air leakage will move 100 times as much moisture through a given opening as would be moved through the same hole by diffusion.Thus we have the appearance of seamlessness because of the tape. hope this answers you question.GeneL.
*
Gene,
Joseph Fusco
View Image
*FreddyLI've I reminded you that you're an idiot. Even a stupid parrot can get it right, what's your excuse.Gabe
*Gabe, I must address one of your lines and use it to illustrate how you jumped to absolute judgement when only knowing half the story."In closing, your project was a water treatment plant, not the White House. Any architect that would specify 3 kinds of masonry for a facade of a water treatment plant should be put in jail for being instrumental in the misappropriation of tax dollars."This Water Plant was nestled in among tens of millions of dollars of prime real estate right on the lake. The original design firm wanted to install 1) a Morton Building or 2) red waterstruck brick that did not match the original sandstruck brick building. So the choice was a pole barn or a prison. The rest of the design was equally unimaginative, uninspiring, with the lowest initial cost as well. The main task here was to make this building fit in. When we were done we had split face exterior/ground face interior block, terrazzo epoxy floors, and complete HVAC and humidity control throughout. All for less than the original designs budgeted at. So when all was said and done we had a terrific, monumental, functional low maintenance building that BLENDED with the surroundings. Personally, I think government buildings ought to reflect some excess. If your whole local government is working out of pole buildings they are doing something wrong.The result is a building that is difficult for me to find from the lake, and I built it!! I suppose blue metal siding and no windows would have been better.-Rob
*Okay Fred, now I have nearly wet my pants!! LOL! I didn't realize how funny Gabe actually was. Have youwritten a translator I can use in Word? Oh - never mind, I forgot your using Wordstar.-Rob
*Joe.I hope you are not long suffering with my denseness.Assuming I understand your question, my initial answer is NO.GeneL.
*Hi Rob,No, I stand by my closing statement.The criteria is, "who" paid for the building. Was is paid for solely by the multi-million dollar property owners, or were there state, and federal funds as well.It so easy to want buildings like schools to be monuments, but of what use are they when at the end of the day, the school boards can't afford new books because their budgets are blown.The fact that you think you build it cheaper than the original budget means nothing. If you could build a designer building below the budget, think of how much below budget a utility building could have been. If your worried about looks, plant trees.What designers build for private clients or themselves is one thing, but when tax dollars are part of the equation, you have a problem.Gabe
*Gene,
Joseph FuscoView Image
*The only thing I could say in my defense i sthat of the petty lawsuits that popped up afterwards, none claimed "loss of property value" as damages.I wish I had the prints to post so you could pick which one you would want in your backyard.A similar plant at the same time downstate NY had contractors providing luxury SUV's for "site travel and other ancilliary uses." We chose to drive our old pickup trucks around instead.Not one mention of "wasted money" by any of the local taxpayers, so I guess we did alright in their eyes.-Rob
*Rob,I've got a little extension for Quark called Jaberwocky that lets you specify a bunch of nouns and verbs and such, and it will generate nonsense-speak that would fly at most business meetings. It's hysterical.Steve
*Joe,It's not the taped corners and such that cause the breach, It's what happens between the drywall and the top plates. The GWB on the walls is connected to the GWB on the ceiling via the taped corner, so when the plates shrink, the GWB on the walls wants to stay with the ceiling, opening the wall cavity to the space above. The wall cavity is usually pretty wide open to air infiltration via the outlets, the bottom of the wall, etc.Sure you will always have other minor breaches like nail pops and scratches in the paint, but proportionally speaking they are insignificant, not "catastrophic." While the 100% continuous ceiling is an ideal that may never be attained, minimizing the breaches is certainly a good goal, and building the partitions after the ceiling is sheetrocked seems to me to be a reasonable and cost effective way to get a more airtight ceiling assembly.I don't see the dubiousness in it at all, nor do I understand your failure to grasp the concept.Steve
*
Isn't it a reasonable approach to seal all the utility penetrations in the top and bottom plates with foam and then simply tack a rubber gasket strip (inexpensive) along all the top plates before drywalling. This should durably seal the wall cavities from the attic.
*
Hi Rob,
I guess that by the number of "petty" lawsuits that resulted on your site, not everyone liked your style of management.
Gabe
*Steve,
Joseph FuscoView Image
*Quark!!! I thought you were a carpenter! My wife is an art director, we have it at home (3 macs) I'll have to check it out.-Rob
*I suppose your career has been absolutely litigation free!!2 lawsuits - settled out of court. Basically squeaky wheels that wanted to get a little grease, no real claims.1 - Noise. Reworked ductwork from dessicant wheel dehumidifier.2 - Site Runoff. Their attorney's surveyor tried to tell us that despite a 4" crown in the road and overkill site grading and catchbasins that our runoff was getting their basement.Everyone was happy after we paved the street and all their driveways.Actually neighbors were quite happy and cordial throughout the whole process, mainly because we addressed their concerns and generally did what they wanted to make them happy. I suppose I could have told them they were all idiots, and they know nothing about anything, and tell them where to get off. But I didn't. I realize I left myself open for you to say that I truly do know nothing, so save it.-Rob
*Hi Rob,As you know, most of this discussion is academic at best. You're not any kind of a project manager, nor are you in any form of upper management. By you're lack of experience I would rate you at the level of a site clerk at best and for all I know, maybe you're just someone who watches "This Old House" and considers himself an expert.My calling someone an idiot does not make them an idiot. I only point out what they already know.Maybe if you were to read and try to comprehend what I write, instead of E-mailing FreddyL for your next instructions, you might learn something.I'm not always right in my comments of course and I don't mind being corrected, but only from people who know what they are talking about and argue honestly. I have and continue to make errors on projects, sometimes it's with products that are approved for a use but were never field tested and sometimes they are just dumb mistakes. I just don't do them twice.Gabe
*Then why even bother answering? I guess I'll renew a vow I made a few weeks ago. I will no longer converse with you. Please do the same and don't address me either. In this way neither of us will be inconvenienced. I'll save my stupidity, and you can save your intelect. You can also save your pride because I'll end by saying that you are right and I am clearly the one who has wronged.-Rob
*Joe,>>This shows your spending good money on the books but, not really learning anything.<<A little broad and insulting, Joe. Please, let's not get dragged into the muck with the others this time around. If it was my saying "nor do I understand your failure to grasp the concept." that set you off, I apologize.The sidewall-to-ceiling joint is indeed a problem in pbv construction. The air-tight drywall advocates say caulk it, caulk the sheetrock at the bottom plate, caulk the plate to the floor, jury rig poly or plastic seals around the electrical boxes, etc. If you blow the sidewalls with DP cells, all the gaps are forever plugged.JAR's coment that a simple rubber gasket and some foam would do just as well is interesting too, but it also fails to address sidewall-to-ceiling leakage. I've taken to sometimes running a strip of poly over the top of partition plates when I do them, and counting on the sheetrock pinching it tight to the next closest parallel joist. (when they run parallel to the wall). I've not tried the "continueous ceiling approach, but all I'm saying is it makes sense to me.Steve
*As we digress from the original post and argue for the best way to prevent moisture from escaping from the interior of the house, it only emphasizes the benefits of a properly installed poly vb inside the exterior shell.For those of you who think that this isn't important in cold climate construction, I would like to draw your attention to a joint US and Canadian study regarding this.Take a minute or two and check out this site.http://sunburn.uwaterloo.ca/beg/methodology.htmlThis depicts an extreme case of moisture exfiltration and helps to demonstrate how damage can be caused by this exfiltration.Gabe
*Steve,
Joseph FuscoView Image
*Rob,First a photojournalist, than a picture editor, then a magazine art director, then switched to design/build in 1992. Art direction in 3D, I think of it as. Even spent a year in architecture school, but wanted to build more than draw. Still spend a lot of time on the mac. Guess I'm one of those weenies you read about here.Let me know if you can't find it. I'll e-mail it to you. It's a barrel of laughs for about ten minutes, then like Jared, butcher of song, you never touch it again till the right occaision comes along. I'll have to program it for "breaktime" speak and see what it spits out.Steve
*You'll be the first to know, Joe. Since it's more likely you'll be doing a 3000 ft. home before me, why don't you try it and let me know how it goes?Steve
*Steve,
Joseph FuscoView Image
*I hoped so, thanks Bill.
*You mean, you haven't already been using it? :)Good taste in computers (we have 2, one of them aqua blue). We mac folk have to stick together.
*I think you've got the principal idea right Steve; also if I remember the sidewalls are not much of problem under Gene's strict approach because he prohibits the placement of mechanicals in them. I assume you could do whatever you wanted with the partition walls. Besides, the use of dense insulation -- cellulose or polyurethane -- smothers the mass movement of air in these exterior spaces anyway. I assume polyurethane wouldn't even allow water vapor to diffuse through it?The mass movement of air is quite powerful -- I have been surprised at the evidence of it that I've dug up poking around the house. In one badly-constructed wall fiberglass insulation had worked its way into the electrical boxes and a starburst pattern of dirt was evident flaring around the outlet plates. Cellulose stopped this more effectively than plastic could have.Anyway, Gene is speaking from experience -- he has built houses using these techniques, and has gradually improved the techniques from these experiences. I have always enjoyed his contributions here.
*Dear Joe Fusco. What could be more dubious than hiding a VDR or as it is sometimes called and air/vapor barier[sic]behind GWB? The glass and metal curtain wall industry has 5 criteria that any material or system must meet if it is to be used as a VDR or air retarder. The fifth one says, "It must be constructed of a material that is known to be durable and long lasting, or be so located that it may be serviced when necessary."There are materials that are more durable and longer lasting than GWB. The beauty of the GWB is its total low cost and its omnipresence allows one to see any damage, which is readily serviced.GeneL.
*Gene,
Joseph FuscoView Image
*Now, Gene, no reason to invoke the number of the Beast.Back to houses -- in a CATHEDRALIZED ceiling, would you prefer cellulose or polyurethane insulation?? I would like to do this with a shed dormer I plan to add to a Cape. (I asked this earlier but it got garbled in transmission.) I figure on 2x8's 16 o.c. to match the existing rafters, all supported by a ridge beam. I'm in the dark on how to insulate this.Part of my curiosity too is that if polyurethane is used as insulation, it would seem to me fairly easy to persuade an inspector that roof venting was unnecessary -- what could there possibly be to vent, other than some solar-induced heat (which the shingle industry says destoys shingles)?
* andrew d,
Joseph Fusco View Image
*LOL! Thx!
* andrew d,
Joseph Fusco View Image
*D ear joe, Hiding in the sense of it is behind the GWB and ergo, hidden.The advantage of the poly vs. a VDR painted GWB is that the poly is there or not there. It is visible prior to covering with the air retarder.The question with a VDR paint is is the coverage and thickness of the paint adequate? However, moisture movement by diffusion is not significant. In a square of painted GWB only one cup of moisture in one year moves through it by diffusion.Polyethylene is often called an air/vapor barrier, or more correctl;y air/vapor retarder. Although it meets the first and third of the five criteria, it does not meeet the meet the remaining criteria when it is installed behind the air retarder, in this case, the GWB.Even if all but the first criterion were met, the polyehtylene is not ACCESSIBLE :-}for repair. By the bye. The issue of whether a material is suitable for use in more than one way is the subject of considerbable research.Polyethylen is the subject of much research and debate. Both the Canadian and Swedish governments have strict regulations governing polyethylene. The poly used by most builders is of a poor quality as it is made from ground up plastic.GeneL.
* Gene,
Joseph Fusco View Image
*andrew d. Joe's point is well taken. Shed dormers ceilings are often difficult to insulate to high R-values because of the shallowness. the low pitch leaves little room over top pl;ates.Sprayed-in polyurethane foam (PUR) which must be installed by a professional, will cost you 4 to 5 time as much as cellulose. I strongly advise you to eliminate all wiring in the ceiling. If you opt for the {PUR but choose to add wiring , ask the electrical inspector if he has any problems with this. He may require you to use a larger size wire; say # 12 instead of #15, but fuse it as #15. The higher R-value of the PUR helps make up for too little space above the top plates. Ifgit is a samll job it may be costly, so ask for a price on using PUR for exterior wall as well.Shingle manufacturers make lots of claims but do not provide written proof of the validity of their claims. Their answer is always, "If you knew what we know about shingles you would know we are right." If there are no cavities to ventilate it becomes unnecessary. Good luck. GeneL.
*No wiring in the ceiling is easy (and you're still using fuses -- you are out of date!). I like the PUR in concept but hesitate to use something that I'll never see the payback on in this mild climate. But heck I'll ask for a quote and it would save me from having to lug the blower around.I have had little trouble following your descriptions of your concepts and they have been consistent to the point of ... tedium ... :) Unlike too many of the folks out there installing Tyvek, polyethylene and kraft paper without knowing exactly why, it's good to see some discussion of WHY we're doing that in the first place ... free of manufacturer promotions. It's like the higher octane gas the oil companies introduced -- almost no one needs it but they sense maybe they should buy it without any reason why. I think your strongest point on the dreaded vapor retarder thing is to argue against any penetrations of the drywall because of the hazard of mass air movement driven by CONVECTION or faulty HVAC through the hole and condensing our large amounts of moisture. The steam from boiling water on our stove condenses out much more liquid water on the cold metal of the exterior vent in a shorter amount of time than would ever form from "diffuse" diffusion throughout the house. Whether one uses polyethylene or not to inhibit the relatively insignificant (if one accepts the premise) DIFFUSION of water vapor doesn't matter a whole lot, but why waste time trying to tape up perfect poly whose seams are probably going to fail anyway, unobserved inside the wall, if you can avoid it?Consistent with you "worry about holes, not pores" position, Freddy has supplied a lot of field experience -- and he seems to spend most of his energy patching holes. Just his pointing out why fiberglas mysteriously can get so dirty while inside a wall made a convert out of me. Maybe you just need some good catch phrases -- Freddy can probably do a top 10.Also I think there is some confusion here between liquid water and water vapor. A material can block one and pass the other -- even polyethylene allows a small amount of vapor through.
*Joe. A rereading of my post shows that I mentioned that most of the poly in residential-and some light commercial construction- is run-of-the-mill off the shelf plastic made from ground up,recycled plastic.It is full of microscopic holes.The Swedish government does not permit the use of such pplastic sheeting. I believe this is also true of the Canadian government,but am not absolutely certain.Of coures if the VDR is damaged during construction it can be easily repaired. but les trusting souls install it on the outside of the inners studs in double wall construction. I never used this technique and wonder how easily it is accessed and repaired in such a location.Accessibility, serviceability and durability are one of five criteria any material or system must meet is they are to be used as VDR or air retarders. The real question might be that given what we know about moisture movement by moving air, is the poly necessary? Good chatting with you. GeneL. Does it matter? The Swedish government thinks so. One could argue as long as the GWB air retarder that covers it is hole free it matters not.The building science community, the 3 model building codes dropped barrier and now use retarder. Are they playing games or are they aware of, among other things, the lawyer sharks circulating above us?
*Gene,
Joseph FuscoView Image
*Hi GeneCanadian standards for poly were upgraded 5 - 7 years ago, and the code requires i 6 mil uv resistive,to be used as a VDR.The upgraded standard was to create true thickness. . . where previous poly rolls could come of the production line 'stretched' to less than 6 mil and still be sold as such. I wasn't aware of the recycled content aspect, and don't know if that remains an issue, although I suspect that the true 6 mil uv has none.regards-patrick
*andrew d. In the absence of moving air water vapor diffusion can be significant.Joe. If the GWB air retarder is intact then the holes in the VDR matter not.I'll e-mail you some references. However, the most recent symposium on air barriers was held by BETEC in November 1998 in Washington ,D.C. Their web page http://www.nibs.org/betecBETEC is the organization that held the last two symposia on Bugs, Mold & Rot. The third symposiais is this June.Patrick. thanks for the info on Canadian action on polyethylene.GenneL.
*Patrick M,Is this "uv resistive" why 6 mil poly is black? I've seen black 6 mil poly specified several times. It can certainly take the fun out of floor framing in hot weather. I kicked a plumbers helper out the pictured hole a few days after this picture was taken in 100 degree weather. Sucker turned beet red and was probably only a few minutes from a ride to the ER. Having fun with the wife's scanner.JonC
*JonNope. . .. the stuff we use is clear, sorta, very pliable, you don'ti accidentlyrip it. I've seen the black stuff used for crawl space floor and under slab like your photo, but it's not specifically required. I always thought the black stuff was more the 8mil variety. . . see it used more to cover round hay bales!!-pm
*Gene,
Joseph FuscoView Image
*
Building a new house and just wrapped all the walls in Tyvek housewrap. Now I am wondering about the ceiling?? Should that be airtight? How? Put plastic up before interior wall sections? Also, I am putting in a lot of recessed lighting - how can I get those airtight?
*Good Morning Cole;Would be nice if those asking questions would start off by indicating the location of the house in question so that we could all get a sense of the actual needs and regional problems and solutions.I'll work backwards on this list of questions by commenting on the recessed lights first. If they are to be installed into an insulated ceiling then they should be inside of a specifically designed box for this purpose. This box is always installed during the roughing in stage of the project.This box is then wrapped with poly over the top and down the sides with about 2 ft. of overlap hanging down.Once the entire ceiling is insulated, you would install the poly and where these fixtures are located cut a hole and pull out the overlap and with accoustical caulking, stick em together making sure you have a continuous caulk seam.With regards to the timing of the poly installation. You frame the exterior walls as standard. Where you are going to have intersecting interior walls, you install a vertical strip of poly, about 4 ft. wide so that you again have a good overlap of 2 ft. on each side. Again when the insulation stage is completed you overlap and seal with accoustical caulking.On the top of all interior wall, during construction, you install another strip of poly, again with the same overlap and again when the insulation is finished you overlap and seal.Any penetrations, pipes, wires, are sealed and taped with tuck tape to maintain the integrity of the poly.What you are creating is a continuety in the poly membrane to make a perfect envelope on the inside.In most homes, a 1x3 wood strapping is installed on the ceiling only, at 12 inch centers and the drywall is then attached to it.The tyvek on the exterior of your house, should serve no real purpose other than protecting the house during construction if the poly is done carefully.Hope this helpsGabe
*Gabe, it must be a regional thing to put 1x3 on the ceiling at 12 oc.Ive never seen that done and the drywall looks great!Is this just another owl killing technique that needs to be re thought?blue
*Do the cels touch the chimney?
*Hello Fred,With regard to gypsum board on ceiling applied first:I am about a week away (finally) from drywalling my sloped ceiling. I have partitions built to 8' flat and not continued up to the ceiling yet, but I do have blocks installed between trusses. How would you attach the top plate of the sloped part of the wall to the ceiling when drywall is present (can't do the floating drywall corner thing). Some time ago Mike M. suggested steel C stud screwed directly to the drywall, but my partitions are stick framed. Suggestions?
*Cole. FredL gives good advice as usual. Your post suggest you have no load bearing interior partitions. If so, install the gypsum wall board (GWB)first. A vapor barrier- poly- is not necessary,but an air reretarder- the GWB- is necessary. If possible eliminate all wiring, ductwork, piping in the attic. Try making the stack vent the only penetration of the air retarder. After installing the GWB air retarder install the interior partitions. Follow Fred's advice on recessed lighting. GeneL.
*Hi Blue,No it's not a regional thing. It's meant to tie in the roof joist to stabilize them and prevent torquing and thereby reduce flexing.Drywall is not really the best material to tie in joists.Gabe
*Cole,
Joseph FuscoView Image
*Joe.Your points are well taken. But the problems you forsee are only problems for those who,knowing what they are going to do is different, fail to hold a pre-framing conference with framers, sheetrockers, plumbers, electricians and HVAC contractors. Indeed, in my book, _Complete_Building_Construction_ I have a section called, Pre-Frsaming Conferences. I note, "The success of these cost-saving measures is heavily dependent on planning and coordination between architect--if one is used--project manager, field superintendent, lead carpenter and his crew, or the frsming subcontractor, and estimator." You just do not hand a set of prints to these people an say build it. "Do not make assumptions that, without specific instructions, the framers will know what to do. Hold a pre-faraming conference with all supervisors and the framing crew. Without specific instructions, the lead framer and his crew will do their best to follow a modular framing plan. But deeply ingrained framing habits are hard to overcome, and framers canand do easily revert to conmventional habits...Incluide the sheetrocker and insulation subcontractors in the conference."An d so on.I usually took the lead framer out to dinner where we were free of phone calls and other distractions. They were given highly detailed drawings--and in some instances video tapes of such a house under construction. The pont then is that you prepare everybody for the unexpected. By showing them what is in it for them you find them more than willing to cooperate.I was always on site to answer questions and keep everybody on track.As for seamless, even the seamless aluminum gutter is not seamless. Yet it works as though it were.GeneL.
*Gene,
Joseph FuscoView Image
*The communication is apparently the key to any deviation from the norm. I had a teacher who used to say that a drawing is complete if it conveys all the details with no verbal exchange.I said that was a good goal, but with challenging (or different) designs people will always do what they've always done, and they'll always get what they've always gotten - shoddy construction. This generalizes, but if you want something done right, regardless of how conventional or unconventional then you better explain the details and the process face to face.Without putting 20 sheets of text on a drawing just explain it. I think Joe speaks from the production framing point of view, whereas Gene, et. al. (including me because I've never production built buildings) look at it from the custom homebuilder point of view. In this area the trade is somewhat divided between custom and production. The airtight ceiling won't scare the custom framers because they can simply come back. The production framer may not have the same crew in a week, so having to come back means greater risk.Maybe I am too naive, but I think most of these concepts, at this point in time, are only practical at the custom construction level. A production house in a tract can't even pick different siding or paint colors, how on earth can you hope to affect the framing? Looked at from the custom build perspective, the airtight ceiling simply means the sequence got changed a little bit and it becomes "no big deal."-Rob
*Well Joe we were writing at the same time, and it looks like we agreed.Are you asking why a mudded and taped drywall corner should be considered differently than continuous butted sheets with regards to an air barrier? To be honest I have started to look at nearly every cut I make as a means of introducing infiltration. The fewer cuts, the less leaks. There are lots of cuts/spaces/gaps behind a corner sheeted after framing. The continuous ceiling negates their effect by blocking leakage paths from the partitions to the attic. Possibly even BETWEEN the back of the drywall and the top plate. Caulk would work there, but it is fixing the symptom not the problem.-Rob
*The kind of jobsite coordination that Gene is claiming is an illusion at best.Most homes are built to code and in a set sequence of inspections.Our houses cannot be drywalled, unless the insulation and poly sequence is completed and inspected.The walls and ceilings cannot be closed until the electrical and plumbing are also inspected and approved.That includes all the work inside all the partitions.Partial inspections would have to be approved prior to issuance of building permits, IF possible.Having trades coming back a dozen times to do their work is ludicrous and very expensive.But hey, Gene, you do it your way. It only makes the other houses look more attrative to buyers on a budget.Your advise gets nuttier by the post.Gabe
*I think Joe has a good point about the taped corner. If the worry is air leakage from the interior of the wall wouldnt it be better to take care of that from the crawlspace or attic. I dont know much about these things because insulation doesnt seem to be taken very seriously here in the south. We seem to just accept high A/C bills as a fact of life. I am interested in learning better ways though.
*Rob,
Joseph FuscoView Image
*Andrew - your question seems to have been lost. I believe code requires that no cells touch the chimney - so I have built a metal "collar" or dam around the chimney and live with that 2" strip sealed against convection but not conduction.
*Gabe, I am always confused with your description of construction projects and inspectors. As I have said I have never "production" built anything, but my experiences seem to be exactly opposite yours. I was recently speaking to a friend who is an inspector in Henrietta, NY about the implications of some of these alternate construction methods, your opinions of these roadblocks, and how to overcome them with your inspector. He said he believes there are a few reasons for your opinions.1 - You do shoddy work, and the inspectors are on you like stink on poop2 - The inspectors are all close-minded and deliberately against change and improving their trade and the state of construction.3 - You need to take some time and foster a relationship with the inspectors up front, so they know what to expect and are not surprised. After a while, he said, he knows how well people work and what their intents and results are. He has relaxed interpretations in cases where the reults exceeded the code expectation though at odds with the wording.He listed several ways that these alternative methods are getting by the inspection phase, and the multiple trade interaction but I don't have time this morning.I did tell hime that my impression was that you would have trouble fostering productive relationships with people, so I'll take number 3 above.-Rob
*Hi Rob,To set the record straight, I have NEVER had a problem with a building inspector.The reason for this is that I have NEVER given them cause for a problem.I HAVE done custom and production on a large scale. I HAVE managed and coordinated several 40 million dollar projects and KNOW the importance of sequence, respecting critical paths and jobsite harmony between all the partners on a construction site.BEFORE you give advice or judge other people's work, walk the walk.Gabe
*Hey Gabe,If you're so popular then why did you only get 300 out of a possible 15,000 votes in our last mayoral election. Just curious.Brian