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I’m having a new home built in Colorado. The general contractor is having half inch dry wall put in for the ceiling, attached to trusses 24″ on center with a coating of interior stucco. Is this do-able or can I expect to see the ceiling drywall sagging in 2 to 3 years? I’ve always seen 5/8″ drywall used for ceilings.
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Thor, I believe in Washington, code requires 5/8" drywall for 24" on center ceilings. Adding a coat of stucco will make the drywall even heavier, causing the sagging to be even worse. No way would I use 1/2 drywall for this, codes or not.
IMHO, jim
*Do your local codes allow for 1/2" at 24ctrs? I would never put 1/2" on the ceilings with that kind of span. As for sagging, I would say yes it will. Check with your local building department, your builder may be trying to sneek one by!Good Luck, Mark Bear
*They now have 1/2" ceiling board that supposedly is as good as 5/8" in 24" spans. I would not use ordinary 1/2" though. I once ran into 1/2" type X, an odd product since it does not come with a 1 hour fire rating, which my supplier said was equivalent to 1/2" ceiling board. If it were my house, I'd go 5/8.
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Your instincts are right... go with the 5/8's, especially at 24"oc. I predict you'll definitely see sag with the 1/2". I'm rather surprised your contractor even suggested the 1/2"
*Having worked for a gypsum company. I know they make an IC board for that very application. I would not use it, but if GC is going that route make sure it is IC board. I know USG came out with a new one sometime last year. Good luck
*What about the new lightweight 3/8" to span to 24" O.C. trusses?
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Code or not, Jim L is right, here in Washington its not code and also not smart. Moisture and weight dont mix when the span is that large.
*The sheetrockers working on my new house have just put up 2 layers of sheetrock on my garage ceiling (living space above). Ceiling joists are 24" o.c. I think each layer was 5/8" type "X", although they might have been 1/2", I didn't measure. I thought the two layers were unusual and they said that 2 layers were required for a 1-hour fire wall with joists 24" o/c.While we're on the subject, I originally spec'ed that all nails, if used, must be deeply set or pulled out to minimize future nail pops. My builder then said that was illegal per fire code. Then I suggested using ONLY screws, perimeter and field. HUGE complaint from my builder ... said it would add a week to my project and cost an extra $2000. Well, I very reluctantly gave in and allowed the "standard" nailing of the perimeter, screwing of the field. WELL, after watching the work in progress this past week, I learned that the sheetrockers can put in screws FASTER than they put in nails!!! And I'm sure that the screws don't cost $2000 more than nails. What the &%$#@*! is going on here? I am now very angry that I have about 50% nails, 50% screws in my sheetrock and I'd bet a thousand dollars that I will have nail pops in 2-3 years.
*Absolutely 5/8. The only time I would listen to a suggestion of 1/2 would be on a sloped ceiling where the board will tend sag less anyway. I still would use 5/8 unless it was a really steep ceiling.
*Gentlemen. For twenty years I had strapped--common East coast-ceilings 24-inches oc., and installed 1/2-inch dry wall. Additionally, 16-inches of cellulose insulation was blown in. This is, of course contrary to common practice and what gypsum board manufacturers specify. But in twenty years not one sagging ceiling. Indeed, one well known builder, Steven Lentz, tells me he blows in twenty or more inches of cellulose insulation on 1/2-inch gypsum wall board. Not one complaint. GeneL.
*I don't know how many 1/2" ceilings I've seen. Once it's installed, it's hard to tell if it's 1/2" or 5/8. I did work for an apartment complex several years ago where all the 1/2 ceilings were sagging like burlap ceilings in a wine cellar.
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I, too, have hung plenty of ceilings of 1/2" sheetrock on 24" span with no sags. Ryan, could those sagging ceilings have had some other cause? Say, moisture?
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I don't know the history. The drywall was dry when I was there. The buildings were about 20 years old at the time. I really don't have any other information.
*Deeply set nails in drywall....yeah that's a good idea. I would suggest you set them just below the paper surface so they never pop. And yes it is true that screws go faster than nails in the field, after it is hung, but not when you are balancing the sheet at the ceiling level on the walls reaching to set a nail at the top. If you are that concerned you should have spec'd kiln dried framing lumber and build the house in the dry season. The nails pops are from shrinking of the framing. I'm going to guess that all the builders here would say that if we were to build our own homes, we would never build them in the winter. The quality goes down 30% and costs go up. Things get much more wet, trying to stay warm while outside causes the subs to say "good enough for who it's for" and the list goes on. We do have to make a living so we keep building, but if it was our own..........no thanks. If you are really picky about quality, build in the summer or fall months. Keith C.
*FWIW, '95 CABO Table 702.3.4 says 1/2" gypsum 24 o.c. & perpendicular (strong direction) is OK, unless spray water-based texture to be applied (then increase to 5/8"). Most here are reluctant to push material spans to the code max, whether joists, sheathing, drywall, etc.
*Here in SoCal, 1/2" is simply not fire rated for 24 oc ceilings. At 24 oc, I wouldn't even think about installing 1/2". We do add a a bead of construction cement to the bottom of each joist as further insurance against sags..When I was starting out, in the midwest, we strapped all ceilings, which would change my thoughts on 1/2", but here in SoCal, we still need 5/8".Nails are still OK here, but I expect the powers to be to mandate 1 5/8" screws soon.
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I used to live & work in Colorado and that was the standard practice there so don't fault him: but I did see a lot of the older places starting to sag. If it were mine I'd want either 5/8" or strapping at 16" oc
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With 1/2" it's gonna' be saggin' sooner than 2-3 years; use 5/8" definitely. Not too sure about "settin' the nails deep".....
Sam
*Only a do-it-youselfer. But both my houses have had 1/2" drywall on 24" truss spacing (standard construction practice for "large" builders here in Maryland) and after seven years there is no sagging (Heck, plenty of bad joints I notice, but no sagging.) Current house is 7 years old with 20" of blown in fiberglass, no sagging. Parents house, similar construction (1967), 1/2" drywall, blown in insulation, no sagging after 33 years.
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I refuse to use 1/2" thick rock on 24"OC. framing.
I've seen too many ugly ceiling sags in my time.
The simple fact is moisture in the air or from somewhere else may cause the rock to sag. Eventually one sees a mild discoloration on the ceiling wherever the rock is attached to rafters or trusses.
Build well! Build with pride!What are those pennies saved worth?!
Mel
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My house is a 1942 job. Ceilings are 3/8" drywall on 24" o.c with blown in insulation. Finish looks like crap from chipping paint etc. but there is no sag. The 3/8" drywall is not at all like the stuff you get today. This stuff seems unusually dense and rigid(more so than todays 1/2") for something 3/8 thick. Anyone know why this is? As a matter of fact the entire house has 3/8" drywall(sheetrock, gypsum, whatever...) for walls and ceilings. They definitely don't make things like they used to.
Gaby
*Just before I got to Gaby's post, I was starting to wonder "Is all 1/2" drywall created equal?" To read this thread certainly makes me question what is the difference between the sagging 1/2" and the non-sagging 1/2".Rich Beckman
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Two variables come to mind:
1. 1/2" rock is stronger over its length than its width, so must be installed perpendicular to ceiling joists. (Remember Andrew D's experiment a few months back, just before the year-end melt-down?) If installed parallel, sagging could occer.
2. Supposed "sagging" could actually be varying crowns of the joists, which could create a wavy ceiling with no actual sags between joists.
*I won't fly out to check your jobs, but I don't believe your claims.Go out and hold a straight edge against your work. You seem to have very easy-going clients! ;)Perhaps, your jobs are all on cathredral ceilings with steep pitches, where -conceivably- pitch MAY influence (the lack of) sagging.Here is the MidWest, I can assure you 1/2" drywall of 24" framing spans won't pass the test of time.Mel
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I'm having a new home built in Colorado. The general contractor is having half inch dry wall put in for the ceiling, attached to trusses 24" on center with a coating of interior stucco. Is this do-able or can I expect to see the ceiling drywall sagging in 2 to 3 years? I've always seen 5/8" drywall used for ceilings.