*
Burr,
No problem at all, but keep in mind it’s a real pain in the butt to tape a vertical joints that tall in one continuous motion.
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*
Burr,
No problem at all, but keep in mind it's a real pain in the butt to tape a vertical joints that tall in one continuous motion.
*
See CABO Table 702.3.4 -- Application and Minimum Thickness of Gypsum Wallboard.
Your proposal is OK per Code, barely: 1/2" may be hung either direction on a 24" o.c. vertical surface. Remember that shop wall tend to get hit with things!
Ceilings: 1/2" may only be hung perpendicular to 24" ("horizontal") joists, either way on 16" o.c. 5/8" is also inadequate.
*Ditto on Andrew's Comments.Having lost one shop already to fire, and lotsa drywall to dings, I would:1. use 3/4" throughout;2. Wherever you store paint; place that stuff in a metal cabinet and/or double up on the 3/4" which surrounds that cabinet.
*Andrew:You bought a copy of the Cabo code book?
*Okay,What's going on here......Sheet rock has no "grain".It's sheet rock for Christ sake........Ed. Williams
*Au contraire, monsieur.
*Yeah, my county requires you to take a CABO-based exam to work here. I haven't, um, gotten around to it, but I've found interpreting the Code (that is, reading between the lines) interesting.It wasn't particularly expensive. I bought it through the AIA.
*F.Y.I.-There is a 1/2 " sheetrock for ceiling use on the market.
*Ed,Without regard to what you've heard, think or know, drywall does have a grain. Drywall hung parallel to 2' o.c. ceiling joists will sag over time. Note that period. If it's sheet rock for christ sake, then try this. Cut two strips of drywall say about one foot by four foot, one with the grain that is not there and one across. Span them across two sawhorses and load them with bricks, or whatever and see which breaks first. Meanwhile have your wife prepare a nice meal of crow. If this experiment doesn't convince you then come over for a texas sized crow dinner at my house and I'll show you my ceilings. By the way, I grew up, well was raised in Sherman, and I still think the Cowboys suck.Tom
*In a shop I would consider using OSB for the bottom half of the walls. Will take abuse and should not cost more than finished dry wall.
*Hello Tommy, I was born in Sherman (Grayson County Hospital), and grew up in Denison. I still think Sherman sucks.(Little High School Rivalry here. Just a little offbeat humor, no real insult intended).James DuHamel
*Tommy B.,Okay,Try this......I'll cut two pieces of dry wall, say, one foot square from the center of two different sheets of dry wall. I'll bring them over to your house and you show me which way the "grain" is going in each piece. My sister got her degree at Austin College in Sherman. She says that Sherman sucks. I already know that the Cowboys suck. I'm sorry folks.........Hardwood has a "grain".......all lumber has a "grain".....it has to do with the tree and the way the lumber is milled. Sheet rock has no grain. It's just gypsum dust compacted and sandwiched between paper. I quess you're gonna tell me that MDF has a "grain".I gotta disagree.Ed. Williams
*Here's the REAL deal....I have read all about the "grain", and how installing drywall (Sheetrock is a brand name of USG's gypsum panel boards)parallel to the ceiling joists will cause sagging. Accordingto USG (check the attached file, or visit at usg.com) there are several reasons for sagging drywall installed on the ceiling. Some are pretty interesting, while others are common sense. Most common reason is moisture penetration into the core of the drywall. The moisture can get there many ways (see file). Another reason is the installation of the wrong drywall panels on the ceiling. Water resistant drywall, according to USG, should NEVER be installed on the ceiling. Just thought I'd toss this in and see what everyone thought.James DuHamel
*I dont see how the gypsum could have a grain, it's poured out in a slurry, I've seen it. If there is any "grain" I'm thinking it has to do with the paper. Chuck
*Interesting points. I'm sure of the "grain", I'm seen the picture of the brick experiment in the Taunton drywall book. CABO definitely distinguishes between panels installed parallel and perpendicular to the wood in span rating.Drywall is made from pulverized gypsum rock that is then essentially reconstituted into rock. It is conceivable that the gypsum particles form chain structures in the direction of the panel's movement down the production line. At least that's my theory, and I'm sticking to it!
*James, totally off subject...I tried emailing you but it was returned as undeliverable.You had a previous thread about teaching classes at HD. I was in their paint shop early this AM, the orange apron showed me a letter sent to all employees that teach in-store seminars.Essentially, at a store in MA, a code official sat in on an "Install a Cieling Fan" seminar. It was nothing fancy, just the basics. After the seminar he approached the instructor and asked to see his electrician's and instucting credentials. He had neither. He was just an employee doing his thing. The official had no complaints with the subject matter, just the fact that wiring techniques were being taught by an unlicensed individual. The state (maybe town?) has fined the instructor $10K and the HD store $50K. They are apealing.I have no knowledge of MA certification matters, but you may want you look into this at your locale. At the store I was at this morning they have put a hold on all seminars having to do with "technical" matters such as elec, plumbing, etc.
*Andrew, Ed, et al..., I agree...Saying it has "grain" may not be correct, in that it's not a grain similar to wood grain. Maybe a "strength bias" would be more appropriate. Take two pieces and lightly score then snap them. Do one along it's length, the other across the sheet's width. Typically the snapped edge that runs parallel to the length of the board will be a cleaner edge than the snapped edge that ran perpendicular to the length of the board. I've always noticed this when snapping boards.It's especially noticeable in 5/8th's inch board with fiberglass in it. The cut along the long edge will be clean, the cut in line with the width of the board will be hairy. It'a all part of the rolling out process when the board is manufactured. As the slurry is compressed and rolled out, the glass fibers align in the long direction. Somehow, someway, something goes on at the particle level during the forming process so as the board dries it achieves a bit more strength along the long axis.If you do much bending of drywall, it's much more noticeable as boards will snap easier if bent along the wrong bias. Ed, you're right in that it sounds assinine, but there actually is a bit more stiffness (thus less tendency to sag on ceilings) along the length of a sheet than across the width. "Grain" may not be appropriate, but it's easily understood as people can relate the strength aspect to the grain in wood.
*I didn't think it was totally off subject at all.I see all kinds of problems with installed drywall. Most of it has to do with wrong type installed in a given situation. This info from USG tells matter of factly what happens when wrong type is installed on ceilings, walls, or elsewhere. It also states problems that can happen if it gets moisture penetration. A whole lot of the same problems I am hearing about here sound like incorrectly installed drywall on ceilings, or drywall that has experienced moisture penetration, not because of a "grain" in the product. This "grain" thing is all new info to me, and I am trying to get all the input from as many of you guys out there as I can. That's how we learn. We share ideas and thoughts. By the way, my e-mail address is [email protected]. I really couldn't tell you what shows up when you click on my name at the top of a post. When I do it, nothing happens.I was simply adding some more meat to the discussion. Ed got battered a little bit for suggesting maybe the info was not totally correct. I just tossed out some more info to discuss.As for the HD thing, I am certified and licensed by the State of Texas to teach Building and Construction Trades classes. I can teach plumbing, electrical, framing, roofing, concrete, and anything else pertaining to the building trades. I am not arrogant enough, or ignorant enough to teach those areas I do not feel absolutely confident in my knowledge and experience of (like concrete and roofing). I know some people who would teach anything that they even remotely knew anything about. James DuHamel
*I think the "strength bias" more than doubles the strenth along the long axis.This is almost interesting enough to contact the company about. Almost.The National Gypsum Company has a much more chatty site about production than USG's, including Gypsum: The Rock That Nobody Knows. I kid you not.http://www.national-gypsum.com/
*
I agree that sheetrock is more likely to sag if installed in one direction. I havew two theories on this. (remember, these are only theories)
First: Installing drywall perpendicular to the joists makes each "span" of drywall only 4'wide instead of 8,10, or 12' wide. Because there are more unsuported edges, slightly more sag.
Theory Two:
If the gypsum slurry is extruded or rolled to the proper thickness, the particles will tend to align with their long axis parallel to the axis of the extrusion. This would certainly explain why the fiberglass fibres are aligned the way mongo mentions.
-Ryan
*
Further up in this thread Chuck mentioned that the paper might be responsible. Ever try to tear newspaper straight? Notice how it's easy ripping down the page, almost guides itself straight, but goes crazy trying to rip across the page? Yep, paper, or at least newspaper, has grain. It's also very important to strength and stiffness since it's out where the stress is greatest. I'll put my 2 cents of speculation with Chuck, and install GWB across the studs.
*I'm going with the grain. No, seriously, I also believe strongly that drywall is stronger in the long axis, and I have seen the little fiberglass "hairs" Mongo mentioned in other drywall besides 5/8". They definitely run in the long direction.
*Your email address here came out for me as an AOL address. As for the HD teaching, I was just trying to pass along a little info based upon your postings on the HD seminar thread that has since been archived. Sounds like you're well qualified to do it all...good luck if you do go the teaching route, it sounds like the store would be fortunate to have you.Regards, Mongo
*Hello Mongo, Thank you very much for the HD info. I will still hold on to it, and ask at the store if they foresee any problems. They are like most companies out there that operate in several states...if they have a problem in one, they close down everything in every state. A long, long time ago, in a galaxy far, far away... I used to have an AOL account. I dropped that sucker and went with Worldnet (AT&T). Have a good weekend.James DuHamel
*WHY is AOL is so successful? They have there headquarters not far from here and are a big ape in the neighborhood. That so many Americans flock to AOL makes me believe P.T. Barnum. But of course i don't understand why people like chat rooms and predigested content. Maybe I'm out of touch with the masses, or maybe the masses don't know what they're missing (like all the ones who don't even try for long-distance phone discounts).
*That's an easy one to answer. HOW they got to be so successful is a pretty cut an dry issue. WHY they have remained so successful is even easier. But I'm like you in wondering why the hypnotized masses are so fond of their service. It all boils down to marketing. They started with the best marketing techniques known to man, and have been improving every since. If a competitor gets big enough to challenge their market share, they simply buy the competitor. They have been doing this since they first started. When the Internet first started to get a little public attention, there were only a couple of online services available. Prodigy was one, and soon came Compuserve. Neither of these services offered World Wide Web access, only their individual sites. The software for these sites was already loaded on the computer, so you either got Prodigy, or you got Compuserve software. Sometimes, on a lavish machine, you got both. You could sign up on either one you wanted, if any at all. These sites were loaded with message boards, stock quotes, a few larger newspapers to read, chat rooms for the members, etc... Outside of their own little world there was nothing. Compuserve people couldn't communicate with Prodigy people, and vice versa. There was absolutely no world wide web access. At this point in time, there wasn't much on the web anyway. Along came a computer geek named Steve Case, who had an idea. Why not have a site like these guys, but offer access to the World Wide Web? Back then nobody really accessed the world wide web anyway. He was just thinking ahead. He offered the same kind of dull crap that Prodigy and Compuserve were offering, but he started marketing his new offerings. He sent out mailers, advertised heavily (which Prodigy and Compuserve did not do), and started making inside deals to get AOL software loaded onto new computers at the factory. Soon, he started sending out free disks, with free hours to anybody that would sign up and check them out. His thinking was that if they sign up, get online, then they would be hooked and stay. He was right. AOL stocks shot skyward, investors flocked to the almighty "Steve Case", and they all lived happily ever after.One day Compuserve started thinking about ways to improve their company, and when Steve Case got wind of it, he bought them. Not many Internet Providers offer a lot to their customers other than just pure and simple internet access. Some have started expanding their sites, but by now AOL has already took control. They will be around for a long, long time to come.James DuHamel
*Yeah, I was thinking about it today and pretty much blamed it on the pathetic blunders of the competition, kind of the same reason DOS became the standard OS way back when. But Case has been smart, and that they survived the "Jetsons" blunder (remember the too-successful TV ads?) speaks well of them.Earthlink (my ISP) and Mindspring (my former ISP!) have merged to try to fight the overvalued Goliath. Note that the expression "AOL" and "AOL s*cks" have been around for about the same amount of time.Remember too that the stocks that fly the highest may plummet the lowest (still wish I'd bought them). Almost all commercial enterprises underestimated the potential of the Web at first. Now investors have overestimated the potential of almost all the commercial enterprises on the Web.
*Andrew, Not to get off track but I got on AOL like most, as a neophyte, and it was easy. I only have time to get on for an hour or so a day. Usually at about 5:30 AM so it is slow traffic wise. I was looking around for a new server and Knology announced they are comming in January. I will stick with AOL till then.Rick Tuk
*Yeah, it's like crack, the first samples are free. I tend to forget what a good selling point "easy" is. But the product is less than you deserve.ISP competition should get quite fierce. AOL will become the AT&T of ISP's -- charging high rates to those it can, discounting to others.
*Burr. Meanwhile, back at the ranch. A sheet of gypsum wall board (GWB) has a stong direction and a weak direction.Suppose you used non-structural sheathing on the exterior of your stud wall. And suppose you wanted to take advantage of the fact that the code rexognizes that GWB can contribute to the wall's racking resistance. Which way must the GWB be hung, verticaly or horizontally? Horizontally,in the strong direction. Why>GWB is more than 40% effective as a brace when installed horizontally.The tensile strength is four times stronger along the length of the panel than across it. Why? Because the vertical edge of the panel is enclosed by paper. This wrappijg with paper confines the core material and prevents the gypsum core from breaking out as the wall is stressed by racking. When the panels are installed vertically, the nail loading along the unpapered bottom causes the gypsum to crack and fall away. Who says so? Ronald wolfe, an engoineer with the Forest Products Laboratory in Wisconsin. GeneL.
*I did e-mail the question to the Nat'l Gypsum Company, maker of Gold Bond d'wall, asking whether the difference in strength resulted from the method of production. Their reply:>Production is the correct answer.Maybe it's some sort of trade secret.... Um, Gene, I didn't know you thought drywall was a "forest product." With all respect, I don't think the edge paper is the difference.Geez, I'm just going to go ahead and try this. Report to follow.
*
Gene,
Are you saying that the wall-board industry could improve the strength of their product 40% (or thereabouts) by adding another strip of paper?? Seems to me that ANY smart manufacturer/marketer would jump at that opportunity to add minimally to their cost of production and enjoy the increased profits commensurate with putting a vastly superior product on the market.
Just my way of thinking, perhaps.
Brian
*Gene,Are you saying that the wall-board industry could improve the strength of their product 40% (or thereabouts) by adding another strip of paper?? Seems to me that ANY smart manufacturer/marketer would jump at that opportunity to add minimally to their cost of production and enjoy the increased profits commensurate with putting a vastly superior product on the market. Just my way of thinking, perhaps.Brian
*
Probably not so easy to do Brian,
The way sheetrockis made is to roll it out the
long way with a huge roll of paper and cut the
sheets off as they harden. To wrap and taper the
ends would require making the stuff one sheet at a
time. Like the difference between sheet-feed
printing presses versus web-fed (rolls).
It could proably be done, but at a much higher
cost per unit, and we all know how many people are
willing to pay a premium for subtle quality
improvements (he said, typing on his Macintosh).
*Hi Andrew,My guess is that it's a combination of the paper wraping around the edge and the compression of the gypsum in the taper. Ever notice how much stiffer and harder to cut the tapered bit is? With that running perpendicular to the joists it would certainly firm it up at least from the edges in. The center bit might still be more prone to sagging.
*
Gene, Steve, Andrew, et al,
Interesting thread....I feel as tho I'm in the company of people who are applying their intellects to thoughtfull analysis.
Brian
*TFF. The answer is no. What I was trying to say was that if one installs GWB horizontally, it is 40% more effective as a brace than if it were installed vertically.andrew d. Did I say GWB is a forest product? The engineers who did the research on wood let-in bracing and on GWB as a brace all work at the Forest Products Laboratory (FPL) In Madison, Wisconsin. The FPL is owned by the United States Department of Agriculture (USDA). Much if not most of the wood research is done at FPL. Ronald Wolfe's paper is,"Contribution Of Gypsum Wallboard To Racking Resistance of Light-Frame Walls. Now that I got my tongue out of my mouth, perhaps I am better uderstood. GeneL.
*
Gene, my old friend, just giving you a hard time. It does sound odd.
OK, gang, some empirical work (when I should be out repainting a client's kitchen because she changed her mind about the color SHE picked out ... and the kitchen is all white, so splatters ... anyway, I digress). The completely nonpartisan AFNR (Andrew's Foundation for Non-Partisan Research) did the actual testing. Method as follows (all measurements approximate):
Two 5"x27"x1/2" strips of drywall were cut from the same ordinary 4'x8' sheet manufactured by USG ("Sheetrock"), the first strip parallel to the long axis of the board, the second perpendicular ("cross-grain"). Both strips originated near the center of the sheet (actually a scrap, I wasn't going to waste a whole sheet on this!) and contained neither long axis edge taper nor edge paper.
The strips were labeled and laid flat across supports several inches above the floor and 17" apart edge-to-edge. First an ordinary brick was placed on each. Then cans of "Friskies," an aromatic meat byproduct concoction apparently intended to be fed to the common feline ("house cat"), were stacked simultaneously on the two bricks. Each can weighed about 6.2 oz gross. Stacking continued until one of the strips began to sink of its own weight at 13 lbs 9.4 oz. (22 cans + 1 brick) aggregate load. After 5 minutes, it broke catastrophically. The failed strip's load was placed on the surviving strip, which bore it without breaking. Loading would have been continued but, alas, the experimenter had run out of Friskies.
The results may be summarized in this photographic record.
P.S. Drywall is 50% or more weaker without the paper, so we wait anxiously for some intrepid researcher with more time on his/her hands or more boring real-world tasks to do than the undersigned to explore the paper's contribution, if any, to this apparent difference in axial strength.
-- andrew d
*LOL! Andrew,Fabulous! And it would seem to validate the grain, even in the absence of the edge tapers.Steve
*Andrew,That is almost too amazing to believe! Nice job!Rich Beckman
*
Joseph FuscoView Image"The price of apathy towards public affairs is to be ruled by evil men." -- Plato
*
Andrew,
Forget law, you should go into structural analysis. Nice work. Any scientific journal would be proud to publish that fine piece of academic experimentation.
and Joe,
You don't need to worry, your superiority is well documented.
-Ryan
*
Thanks. It was kind of fun, like those science experiments where you make a battery out of a lemon.
As I mentioned, I originally saw the experiment flipping through the taunton drywall book -- by Myron Ferguson. I still wish I knew the reason for the difference...
*Ryan,
Joseph FuscoView Image"The price of apathy towards public affairs is to be ruled by evil men." -- Plato
*anD,Are those Friskies? I quess you may just have more cats at home than I do.Ed. Williams
*
Wow, you're a scientist, too?! Great empiricism, very elegant (in the mathematical sense).
Now that you have me thinking, I see that Burr's original question about hanging the GWB vertically would put the strong axis of the GWB right where it needs to be: perpendicular to the force of gravity. No worries about sagging...but be careful when nailing or screwing close to the edges. Finally, it's his SHOP...shouldn't some experimenting be OK there? (I have hung plenty of rock - GWB - vertically with good results, but those long vertical joints are hard to tape, requiring the taper to start his pull through the mud from a ladder and end it on the floor. So much easier to tape horizontal joints.)
*
Yeah, I started hearin' about a high density 1/2" board for lids a couple years ago.
And I don't think the Cowboys suck, they just got old, lost a few free agents, and other teams caught up with them. - jb
*Hi Andrew,I got on AOL about 3 years ago because it was simple. I'm pretty tech savvy, but everything in print at that time about getting on the web was full of technobabble. Far more than even a relatively computer literate person wanted to deal with. AOL was simple. Load the software. Go. Why bother with all the arcane networking protocals and such if you don't have to.Of course now all the ISP's are the same way, but I've become fond of my e-mail address. I never use any of the proprietary AOL content anymore, though I did in the beginning. Now that ISP prices are dropping I'm probably going to switch to a straight ISP. If I can get accepted for the Freemac.com promo (get a free iMac with three years of Eartlink and a no-fee credit card) I will jump on it. I've got a big enough monitor that I'm also considering one of the free ISP deals with the indelible ad banner.Just some thoughts from a fellow Mac user who is also technically adept and an AOL user in spite of it.Steve
*Too bad Apple didn't go into the ISP business or pursue Cyberdog. The package that comes with the iMac to instantly set you up with an ISP account works great -- just answer a few Qs and type in your credit card number ... though they unfortunately cut back on the number of ISPs, right around the time they starting displaying IE prominently and hiding NS.... oh, and at the time i was shopping for an ISP AOL was still charging high fees to "let" you access the Web. Since the Web was all I was really interested in (had e-mail at work), I went elsewhere. True, I had to deal with baud rates, DNS addresses, and other horribles. But I learned a lot!I strongly recommend to anyone who sees lots of e-mail in their future to get an ISP-independent account that forwards mail transparently and instantaneously to your current account. You may be able to get it free from some institution you've been associated with, such as a college or university, or for a few dollars a years from various commercial enterprises. Once you have the address, you can switch ISPs at the drop of a hat without losing mail.We actually went a step further and purchased our own domain -- e.g. http://www.yourname.org
*Hi Andrew,Apple will probably announce their own ISP service w/in the next six months. This has been a hot topic on the Mac rumor sites for some time now. You might want to bookmark http://www.macosrumors.com and http://www.macsurfer.com MacOSRumors is very accurate about what's coming out in the next few months or so, and is particularly useful if you are trying to figure what to buy and what to hold off on buying. MacSurfer is more of a general Mac news roundup site.Steve
*Why you pickin' on andrew so much these days? I've had to cringe in a couple of different threads lately.Steve
*Well, I think this pretty much shows the importance of grain in sheetrock!(I had no idea they had ISP plans ... maybe i should be a CEO.)
*
I'm aware that sheetrock has a grain that runs parallel with the length of the sheet. The last issue of Fine Homebuilding addressed possible sagging if 1/2" rock is hung on the ceiling parallel with the joists rather than perpendicular to them. For several reasons (less waste, fewer butt joints), I've been considering hanging 1/2" vertically on the walls of my shop (studs are 2 feet o/c) rather than horizontally. Do any of you experts foresee problems with this?