In the past I have noticed some discussion about the use wood screws in framing. While watching a “This Old House” episode, The prefab panels were being anchored to the sole plates with screws and the panels were being fastened together with what look like 12′ long screws.
A lot has been said about the lack of information about the shear strength of screws vs. nails. If I remember correctly, Piffin or the Boss are not a fan of screws. At least, not of drywall screws. Any comments?
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I was just reading in one of McDesign's generous gifts of old FFW mags from last year where it said bold as day that drywall screws were usually used to put up kitchen cabinets. I kid you not!
Behind the ostensible government sits enthroned an invisible government owing no allegiance and acknowledging no responsibility to the people. [Theodore Roosevelt]
Hmm. I know it's wrong, and I don't do it, but has anyone ever seen a kitchen job fall down just because of drywall screws?http://truenorthcarpentry.net
Never used them myself like that to see it but do remember some here mentioning during renovations doing cabinet removal
and finding something like 3 out of the 4 drywall screws holding an upper kitchen cabinet up had the heads already snapped off thus being held up by the one screw which puts it awfully close to falling down.
I recall once listening to a judge show in the background when doing something else and hearing of a court case bought by the homeowners against a contractor over kitchen cabinets that had fallen down breaking a load of dishes in the process.Behind the ostensible government sits enthroned an invisible government owing no allegiance and acknowledging no responsibility to the people. [Theodore Roosevelt]
"and finding something like 3 out of the 4 drywall screws holding an upper kitchen cabinet up had the heads already snapped off thus being held up by the one screw which puts it awfully close to falling down."OuchFor reals.http://truenorthcarpentry.net
And what if a child were under that cabinet? Oh, the humanity ;)GK
"has anyone ever seen a kitchen job fall down just because of drywall screws?"The answer is NO.But the path to that answer is long and rocky.A lot of shoulds, coulds, and apple to orange comparisons but nobody with any real evidence.I really gotta finish that screw testing jig I started after the last argument!GK...still using dw screws
Your middle initial isn't "R", eh?
Corporation: n. An ingenious device for obtaining individual profit without individual responsibility. --Ambrose Bierce
A little too soon for the name calling, DanGK
The answer is not no.
Somebody posted a photo here of a bank of them that had fallen, dishes spilled out and carcass broken.
I regularly find on remo-demo work that those hung with SR screws have broken screws and are barely still hanging up and on the verge of falling
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
"Somebody posted a photo here of a bank of them that had fallen, dishes spilled out and carcass broken."Hmm, I did not see that picture. Last time you and I had a bout over this there was only one person who said they had a cabinet fall, but they admitted it was overloaded and I think it was a cheesy peninsula installation. 4 screws will hold a cabinet up to and beyond the cabinet's maximum load capacity. "I regularly find on remo-demo work that those hung with SR screws have broken screws and are barely still hanging up and on the verge of falling"The verge of falling is opinion and not that I don't respect your opinion but this matter really needs scientific facts. DW screws break easily in torsion but resist shear quite well...not as good as some other screws, I admit, but plenty well enough for every application I have used them for thus far. I REALLY gotta get that screw tester going......GK
"DW screws break easily in torsion "THAT is exactly the problem. A screw that is designed and built with enough strength to handle torquing up against a paper surface cannot handle it when the shoulder comes snug against a hardwood surface so it fractures. Even in cross section, a structural screw has twice the displacement of a sheet rock screw.Hint - they are called sheetrock screws for a reason. They are not wood screws. I really don't recall you in particular from a previous conversation, this subject comes up fairly often. I guess you didn't make that big of an impression."The verge of falling is opinion and not that I don't respect your opinion but this matter really needs scientific facts"I'm dealing with facts - it isn't too hard to look up the strength of various screws. The links I posts from GRK list what their screws are capable of. Facts is that drywall screws break when used in hardwood. BTW, I'm not looking for the respect of somebody who uses SR screws for cabinet work. your customers deserve better.
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Edited 10/31/2008 4:54 pm ET by Piffin
Piffin,QUOTE: "THAT is exactly the problem. A screw that is designed and built with enough strength to handle torquing up against a paper surface cannot handle it when the shoulder comes snug against a hardwood surface so it fractures. Even in cross section, a structural screw has twice the displacement of a sheet rock screw."That statement doesn't even make sense! You are somehow trying to compare the rotational force it takes to pop the head off a screw to the amount of force it takes to sheer a screw? If a screw head breaks off I would put in another screw next to it (not that that happens often). Even if a screw head did break off and I left it, there is still sheer holding power. The rotational resistance of the screw is compromised but the majority of the screws strength is in it's sheer capacity anyway.QUOTE: "Hint - they are called sheetrock screws for a reason. They are not wood screws."I realize the nomenclature might throw you a bit, but I am yet to run into the drywall thickness that may require 2-1/2" drywall screws. In reality they are simply general purpose screws for fastening together wood, plywood, plastic, and drywall or any combination of those materials.For a "structural screw" to have twice the displacement of a sheet rock screw, it would need to be roughly twice the diameter of a sheet rock screw. Somebody needs to learn some simple physics.QUOTE: "The links I posts from GRK list what their screws are capable of. Facts is that drywall screws break when used in hardwood."First off, the GRK tables you post are for their own screws and mention nothing of comparable drywall screws. Second, the GRK sheer ratings are ridiculously high for what is needed to hang a simple cabinet. Their least rated structrual screw is for 829lbs and assuming you put four of those in one cabinet you are then able to support 3316lbs!?!?! What cabinet structure is made to hold one and a half tons? Who puts 1.5 tons of dishes in a cabinet? Third, who cares about the performance of drywall screws in hardwood? The cabinets I hang have plywood backs and I am only concerned about screwing them through 1/2" drywall and SPF studs. The face frame connection (admittedly hardwood) is mostly aestetic to conceal tell lines between units. If properly predrilled, then never a screw failure. To be frank, your argument is weak. Yes, you did provide some scientific facts but the numbers are unnecessarily high. I might as well be lag bolting every cabinet to the wall. You have in no way proven to me that it is hazardous or negligent to use drywall screws to hang a cabinet. I hang and often build cabinets for a living. I learned to do so from two separate carpenters who have each hung tens of thousands of cabinets in thousands of kitchens and baths. I have previously asked both of them about the type of screws they use to build and hang cabinets with and they each said the same thing...drywall screws. 30+ years each and NEVER a screw failure. You, Piffin, I am sure has also never had a screw failure but the screws you use are way more than is comprehensibly necessary to hang a simple kitchen cabinet. While engineering is a field I know and enjoy learning about, over-engineering is not so worthwhile a trait. Get your facts straight, then tell me something.GK...with a real degree from a real university, so I don't need to attend your TUofK.
You might wanna back it off a bit there, fella. The guy you're dissing has already forgotten more than you'll ever learn.
For instance:
I am yet to run into the drywall thickness that may require 2-1/2" drywall screws.
You've never run into two layers of ¨ý" gyprock over metal studs on a fire-rated wall...?
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
"You've never run into two layers of ¨ý" gyprock over metal studs on a fire-rated wall...?"You got me, I have not. I have run into many double layer and fire rated walls but I'm not really sure what you are talking about.But at least I have the screws for when I do:)GKEdited to ask what the little "y" means anyway.
Edited 11/1/2008 12:34 am ET by Dreamcatcher
Edited to ask what the little "y" means anyway.
It means, in this case, that the server isn't recognising the keyboard code I'm using. That was supposed to be a unified 5/8 pi character, which is a CTL+shift+6 on the Canadian multilingual keyboard. Normally, they come through fine but not yesterday.
Let's try it again today...¨ü ¨ý ¨þ
Edit 1: Nope. Maybe in Unicode...?
â…œ â… â…ž
Edit 2: Ah, there we go.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Edited 11/1/2008 4:19 pm ET by Dinosaur
Edited 11/1/2008 4:20 pm ET by Dinosaur
Here's what I see on my computer:
Let's try it again today...¨ü ¨ý ¨þ
Edit 1: Nope. Maybe in Unicode...?
â…œ â… â…ž
Edit 2: Ah, there we go.
I don't see 5/8, so I don't think that you got it in that one either.
Sorry, Don. I've been using these special characters for years on BT and never had a problem with Prospero before. To get them to show up on my own screen properly in that last post I had to change the 'Encoding' selection to Unicode on the 'View' menu of my browser.
Weird part is, they showed up correctly when I typed them into the message entry box, but then didn't when I posted the message.
I dunno what's going on...unless those characters have been appearing to the rest of you guys as gibberish all these years and nobody ever bothered to say anything.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Edited 11/1/2008 11:29 pm ET by Dinosaur
No worries. I only recall seeing an occasional funky character and I don't remember if it was from you, but I've always been able to decipher the meaning from the context.
"unless those characters have been appearing to the rest of you guys as gibberish all these years and nobody ever bothered to say anything."yeah, we overlook minor thing like that a lot except when the moon and stars get the wrong alignment...;)An occasional little one is not bad, but there are times when somebody on an Apple does a cut and paste and the whole darn thing get so ginked up it is unreadable with strange characters
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Okay, just so I get an idea of what part of my posts come thru to you in the clear, tell me if the following lines read as intended or not:
¼ ½ ¾ (should be 1/4 1/2 3/4)
⅜ ⅝ ⅞ (should be 3/8 5/8 7/8)
Éé (E followed by e, both with acute accents over them)
â ü ç (a with circonflex; u with umlaut; c with cedilla)
Underlined (word 'underlined' should be underlined)
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
all as described
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Ahhh. Good. Sounds like all is right with da world...or at least the server likes the flavour of my keyboard better tonight than it did t'other day....
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
"The guy you're dissing has already forgotten more than you'll ever learn."LOL, I wish folks would quit focusing on how much I've forgotten - been accused of that very thing a couple of times.;)
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I wish folks would quit focusing on how much I've forgotten -
Who're you again?
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
heh heh Dreamcatcher's got a hardon for Piffin.Behind the ostensible government sits enthroned an invisible government owing no allegiance and acknowledging no responsibility to the people. [Theodore Roosevelt]
helps keep the fights out of the Tavern!;)
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The fact that I find so many cabinets with heads fractured off but still in the hole tells me that a lot of guys are doing it without being aware. I suppose that the fracture starts without complete separation until latter when loads are put on the cabinet and the tiny diameter starts to tear and pull through the wood. This explains why so many carpenters THINK they have never had a screw failure. I saw the same thing with my own work from years ago when I started out and used SR screws like every other ignorant carp around. Occasionally would have to backa screw out to reposition or remove a cab and found out how many had sheared, though I never realized it when installing.It is really not uncommon at all for screws to shear. even on roof metal, the thermal stress pops heads of the tex screws. Micro-fractures are there in the metal and failure comes later. It is wise to use the best instead of what just is easy, cheap and something to get by on.you seem to be disclaiming your original by stating that you might be using screws other than SR screws now since they are 2-1/2" long. I can't see your screws from here so all I have to go on is your claim that you have been using SR screws. (But I do quite a bit of SR work with longer SR screws too, when installing over foam). Anyways, I agree that a lot of guys call any black phillips headed screw a SR screw even though it may not be one. Maybe that is what you are using and arguing for no reason.you say
"For a "structural screw" to have twice the displacement of a sheet rock screw, it would need to be roughly twice the diameter of a sheet rock screw"That is patently false. Check your math for the area of a circle. increasing an eight inch shank to 3/16" roughly doubles the displacement. But no SR screw has a 1/8th shank to begin with. Further, structural screws are a much higher quality metal. Like I said, you can look up the values for your SR screws and compare them to what I posted for the GRK cabinet screws. I think you'll see about 40% or less. Want me to do it for you or would you rather just pick fights on your weakest arguments? Maybe you just have a hard time reading. For your reference, you used shear strength of the GRK STRUCTURAL screw, not the cabinet screw. I don't think anybody is going to use a 5/16" RSS for hanging a cabinet so your point about it being rediculous to do so is moot. Want to talk cabinet screws vs SR screws or are you just enjoying a good fight? you'd need to look up the actual values for the actual screws.I can save you the trouble - average design load shear strength of your SR screw is about 150# while the cabinet screws are rated to a little over 300#. Further, the heat treat process for the SR screws is inconsistent which is why report is AVERAGE. several will fail at 75#. For cab screws, you have a guaranteed consistency."The cabinets I hang have plywood backs "
So that plywood is paper and not hard wood, eh? Have you ever noticed that plywood is harder than paper gypsum board? Are you really awake when you are hanging cabinets or writing this stuff? You are trying to make arguements based on facts that dispute your own position!finally for all - re the OP Q -
http://www.iccsafe.org/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=10;t=002062
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I was almsot tempted to put up my kitchen cabinet with drywall screws and do chin ups on it just to prove they will work..
The fact that I can't do a chin up anymore kinda stopped me.. <grin> and I wound up using a simple french cleat with screws I removed previously..(that appeals to my frugal nature)
I'll bet darn few would ever reuse a nails they pulled out
Yes, but it's in a trailer where I live after a divorce. It's a 1985 single wide, so it's not up to the usual building standards and it's wracked because of settling probably from armadillos. Does that count?
I wouldn't do it in a paying clients house. But on occasion in my own house I have used drywall screws to anchor a cabinet or two.
I have had to remove some old cabinets and they will stay on the wall with nothing holding them on. If the cabinets were installed shortly after painting they have a way of sticking to the paint and becoming a part of the wall.
Yeah, I've run into that myself.Nothing like a little help! ;)http://truenorthcarpentry.net
Screws have different shear and breaking strengths depending on how they are made. Take a bright galvanised screw, for example, and a gyprock screw. Bend. See which snaps first.
The problem is a lot of people who would use screws don't know this, and gyprock screws are ubiquitous on jobsites, so they get used inappropriately just because they're at hand. Not good.
Worse, it's inefficient and costly. In a pre-fab or panelised construction, it makes a certain amount of sense to use screws for assembly of large units, so long as the screw length, positioning, and grade is specified by the engineer who stamped the drawings. But for standard stick-frame construction, it doesn't. Nails aren't used in tension in stick-framing, so the lesser withdrawal resistance of a nail versus a screw isn't an issue. In sheer, nails beat most screws handily because even the softest screw is more brittle than a common nail.
And even using impact drivers and screw guns, nails are still faster to drive--immensely faster, if you use a nailgun--and less expensive per fastener, than screws.
Dinosaur
How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....
structural screws have thier place for pulling things together such as built up beams, posts for railings, etc. I like the grk screws albeit they are expensive."it aint the work I mind,
It's the feeling of falling further behind."Bozini Latinihttp://www.ingrainedwoodworking.com
structural screws have thier place for pulling things together such as built up beams, posts for railings, etc.
Agreed. I think I said more or less that, or implied it. If I didn't, I should have: I use a fair number of #12s and lag screws in framing for just those kinds of things.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
GRK are just about all I use. I don't think of them as expensive in the least, because they save so much time in labour compared to philips bits camming and stripping out. Even square drive don't do as well.But those big old 12" structrual lags self drill right into dense wood with no pre-drilling in no time at all.
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However when you run those big lags in without predrilling pilot holes and shank holes you weaken the potential strength of the connection..
Interesting that this discussion deteriorated to talk about sheet rock screws.. the weakest screw imaginable for structural use..
Frankly I'm in agreement with you regarding the use of sheetrock screws for structural use.. It's a no-no..
I also agree that properly installing any screw is far more labor intensive than installing any nail..
Once we're past that point can you argue the the wise selection of the correct screw will provide a stronger connection between two pieces of wood than nails?
Maybe you did no t look at the ones I use - they are self drilling with a cutting tip. I've never seen one split wood.
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Piffin
I've seen those myself, not in the sizes I used but smaller ones.. I see two problems with those..
first is scarf or frass or whatever you want to call the sawdust/woodchips left behind when something is drilled out. Obviously that never leaves the hole so in effect all you are doing is tearing out fibers and jamming them back into the same hole.. I could get all scientific and explain how two differant things can never occupy the same space but well .... you are simply compressing wood and the steel of the screw into the same place.. it may not fail depending on a lot of things but it cannot be as strong as a properly prepared hole.
And second the increased pressure of compressing the wood fibers/sawdust/ whatever, increases the friction of installation thus calling for a great shank size than would ordinarily be required. That or the quality of steel is higher which adds to the cost of manufacture. Plus adding to the risk of camming out or rounding off heads etc..
Look I understand you're not making a piano and maximum strength and duribility isn't at a premium. The insanity I go through is clearly not for everyone. But I've found relatively simple ways to do it reasonably quickly.
Wouldn't it be nice to just once in your life not worry about the time or money involved and build things as well as you possibly can?
Pulling the trigger on a nail gun may certainly be fast and it's acceptably strong so you aren't wrong to do as you are doing..
I doubt however it gives you the same feeling of craftsmanship that sliding a tenion into a tight mortice and hear the satisfing thunk, .... whoosh of air escaping at the last second as it slides home. Knowing on that day, at that moment, you've been a real old world craftsman?..
Once you do that I donno, know it somehow changes you.. You want to drill a pilot hole and a shank hole. You want a counterbore to plug with a tight peg. You know the hole is right and smooth but you can't resist taking a moment to slide your little finger in and roll it around feeling that smoothness caused by a sharp cutting edge making perfection..
"I could get all scientific and explain how two differant things can never occupy the same space but well .... you are simply compressing wood and the steel of the screw into the same place.. it may not fail depending on a lot of things but it cannot be as strong as a properly prepared hole. And second the increased pressure of compressing the wood fibers/sawdust/ whatever, increases the friction of installation thus calling for a great shank size than would ordinarily be required. That or the quality of steel is higher which adds to the cost of manufacture. Plus adding to the risk of camming out or rounding off heads etc.. "GRK already has gotten all scientific on those points. They use the highest quality steal in any screw available at retail. They designed the head with the Torx bits style to avoid cam out. The shredded wood fibre in the hole is compressed and the addition of friction adds to resistance to pull out. Similarly to nails, the holding power is directly related to the volumn of wood displaced and friction created up to the point where wood splits, so the tight hole is the better hole.Cost is higher for the screw, but the net is a cost savings because of labor saved.To be caler re ther rest of your comments - I use structural screws a LOT!
They are great for minor repairs, and in remo situations where the thumping of a hammer can crack plaster on the other side of the wall assembly. They draw things together better in fussy locations. I LIKE screws for the right job and the right place.But they are totally out of place for a whole frame job, or when using the wrong screw for the job. THAT is what I rail against. Wasting money or getting people hurt are stupid moves, IMO
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As I've said, I understand why you frame with nails.. Why you don't timberframe..
I know all that,, but tell me, don't you get a great feeling exceuting a perfect mortice and tenion connection? Don't some things give you sensual pleasure to do and you don't or can't do them because of costs?
There is no structural reason to build a house with 18 inch thick walls. I did it because I wanted to.. I wanted walls that were massive and would last over time.. I could have choosen any number of woods to frame with but I choose the woods I did not because they were easy but because of duriblity.. That to me is the real definition of luxury. The ability to do what you want too, How you want it done..
Finally; We are in complete agreement that the wrong screw should never be used in the wrong place..
Sheetrock screws (piffin screws) have darn few uses other than sheetrock..
"Sheetrock screws (piffin screws) have darn few uses other than sheetrock.."LOL, My wife tells me they do a passable job at hanging pictures, and at letting the air out of her tires.Yes - on the pleasure of doing certain things that others cannot or will not, and doing it well.
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HANGING PICTURES WITH SR SCREWES!?! GAAA!!!
That's whut nails er fer!
What - I couldn't stay out of this thread forever!Rebuilding my home in Cypress, CAAlso a CRX fanatic!
I don't feel it's healthy to keep your faults bottled up inside me.
wut can I say man, she's a woman...There - that oughta screw this thread up good now!;)
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Just cause I feel like stirring the sheit today!
This link directs to a company that makes 12' and 16' screws!!!!!
hehehahahoho
I should be outside doing something constructive, but instead im stuck here again!
http://www.augerscrews.com/October 17th, 2009
Jeremy and Lisa
Was there ever any doubt?
Just cause I feel like stirring the sheit today!That link wouldn't be for a sewage pump auger, would it?;)
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Yalp!!!!!October 17th, 2009
Jeremy and Lisa
Was there ever any doubt?
Yeh, I agree they do make acceptable picture hangers.and she's absolutely correct with regard letting air outside of tires.
are they as good as piffen screws?"it aint the work I mind,
It's the feeling of falling further behind."Bozini Latinihttp://www.ingrainedwoodworking.com
Ahem....Do you realize that the term "piffin screw" is a humorous sort of facetious parody of the fact that I hate to see weak drywall screws used for structural purposes like hanging cabinets?To answer the Q, a piffin screw is a SR screw, so no - they are not half as strong as the GRK cabinet screws.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
just joking around. I've followed some of the old posts"it aint the work I mind,
It's the feeling of falling further behind."Bozini Latinihttp://www.ingrainedwoodworking.com
Try these; best of both worlds....
View Image
http://www.911-nails.com/index.html
very cool product. Looks like a huge time saver for decking.
I saw them in the "new product" section of a trade magazine about two years ago and thought it would create a major shift in the collated fastener market, i.e. quickly become the standard fastener used.But, until about a month ago, I haven't heard anything more about them.I'd love to hear a review from anyone who has used them. I wonder if they jam guns easier or if they are just too darned expensive to be worthwhile.gk
Next time I have an opportunity to use them I will post a comment. I also read on the link that you posted that they make screws for drywall applications.
A screw isn't just a screw. Some screws, like drywall screws are hardened. Too much torque on the head or a shock will cause them to snap. Don't ever build scaffolding or assemble structures with these type of screws. They can fail catastrophically in shear stress.
You can use screws, you just have to use the correct ones. using the correct ones can be a lot of extra work and expense. You often have to pre-drill. Mild steel screws have mild steel heads. If a screw starts driving hard, you may strip out the head. A screw that has the same properties as a 16d nail could be a 3 1/2" #10 or 12. That's not an easy screw to drive and you often use 200 pounds of 16d on a house.
The correct screws are great on things like decks and subfloors. The typical stress on a floor can work nails, even spiral nails, loose. You have to be careful, there are some crappy screws on the market. Just because they meet the size criteria doesn't mean they are the strength they should be.
There are places and circumstances where a few screws or lag bolts are just what's needed. As far as framing with screws, it doesn't make practical sense. There are far more disadvantages than advantages.
Beat it to fit / Paint it to match
"Don't ever build scaffolding or assemble structures with these type of screws. They can fail catastrophically in shear stress."I was in a safety training class. At the end of the class, the guy was running through his photos of accidents he had investigated on sites for examples to drive the point home.Got to a slide showing a bunch of two bys all helter skelter up alongside a house."Three guy went to the hospital from this one. One later dies. This stagging was put together with sheet rock screws."
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Maybe you know... why are drywall screws hardened?
There doesn't seem to be any structural need for these screws (in their proper application) to be hardened and I would assume it makes them more expensive.
Could it have something to do with making them rust resistant to the wet spackle that they're exposed to?
Drywall screws are hardened to prevent the recess from deforming when the bit cams out and so they can penetrate 23ga studs.
The awful thing is that beauty is mysterious as well as terrible. God and the devil are fighting there, and the battlefield is the heart of man.- Fyodor Dostoyevski
http://forums.taunton.com/tp-breaktime/messages?msg=104239.1
Thanks for the link! Saves me from retyping.
http://forums.taunton.com/tp-breaktime/messages?msg=104239.28Rebuilding my home in Cypress, CAAlso a CRX fanatic!
I don't feel it's healthy to keep your faults bottled up inside me.
Thanks for the link! Saves me from retyping.
No problem. That's why I posted the link because it isn't worth retyping.
Joe Carola
I think someone should link that every other post!>G<
It should be a sticky.
http://forums.taunton.com/tp-breaktime/messages?msg=104239.1Joe Carola
The question in my mind ios why anybody would want to frame with screws. It takes longer and gives a weaker job. Erecting panels is different, not too many 12" nails that can suck things like that together well.
There are screws made for framing, by GRK and Simpson, but they get mighty awfully expensive. For the added cost of them on a typical house, you could go out and buy a compressor and pnuematic gun or a Paslode gas nail gun
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Taunton University of Knowledge FHB Campus at Breaktime.
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"The question in my mind ios why anybody would want to frame with screws."Because they can't swing a hammer.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Okay here goes 'stupid question #500': I am NOT a professional contractor. I do jobs on my own house. I do not use screws for framing. But, I have used them to put up bathroom/kitchen cabinets. What should I be using? I am in the process of remodeling a bathroom and there will be a series of hung cabs on the walls? Thanks - and please be kind in your reply - I am a gross amature. Mike
GRK cabinet screws. Just use a light trigger finger, cause they'll bore right through the back of the cab if you don't let go fast enough.
Conscience is the still, small voice which tells a candidate that what he is doing is likely to lose him votes. --Anonymous
http://www.grkfasteners.com/en/CAB_1_information.htm
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I have a dozen plus hammers and 8 pneumatic nail guns, yes I use them all but my place is framed with screws.
Strength is the reason.. a nailed rafter takes 208 pounds of force to fail and a rafter with a single 3/8ths lag screw requires 2783 pounds to fail..
That's not even properly installed!
If you've ever seen a roof peeled off in high winds or a tornado you understand the need for the added strength..
You never did answer the Q when are you going to start screwing your shingles down.
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Grin,
Well I was tempted early on to duplicate what I saw on an old barn in Wisconsin.
The shingles were installed not using nails but wooden pegs!
Estimates varied but the age of the barn clearly predated the civil war and I can see a frugal farmer carving out thousands of white oak wooden pegs during those cold winter nights where winter lasts 9 months of the year and your only entertainment is to work with what nature provides.. heck nails would have been expensive and since they didn't have stainless steel nails back then likely to fail long before these did..
Why didn't he carve screws? Just lazy you think?Like the song says: merrily, gently and downstream
I'm just trying to imagine the time it took to carve out of white oak the thousands of wooden pegs used.. and then trying to imagine sitting up on those rafters hand drilling the holes for all those pegs!!We're talking about a barn that was probaly 80 feet long and 40 feet wide.
I'm well aware of the problem of using drywall screws for purposes other than their intended use. I'm also aware of the time factor of screws vs nails(gun and hammer). Like many things around today's building site, the screw, in it's present form, is a relatively new comer. My introduction to the screw was with slot and a plain old screw driver. (please, no age comments.) The screw was the last thing you used.
My question is, is there any authority out there about the use of screws in the building industry? It is pretty well known what a nail can do. What the withdrawal, shear etc. is. There are nailing schedules etc. for nearly every possible connection. Has the screw industry done the same for the vaunted screw. At least something that the guy on the ground can use as a guide for their proper use.
Screws have there place. Spend almost as much time taking things apart as I do putting things together. A screwgun in reverse beats a catspaw anyday. For structure, I prefer nails most of the time. Wall sheathing, on the other-hand, I use screws just to make it easier on the next guy ( even though I'm not sure whether or not that meets code here).
Just so everyone knows, the shank on a clip of nails for a nailgun is alot thinner than a hand-drive nail of the same size.
Re: "what look like 12' long screws".
I really want to see a 12' screw, ya know?
I've got about 5000+ 12 x 1/2 inch hardened stainless steel lag screws in my house plus another 2500+ 3/8ths x12 hardened stainless steel lag screws.. the really long (16 inches) screws are used for roof panels that are 13 inches finished thickness.
Go to 85981.1 & 94941.1 in advanced search over on the left.. scroll thru to check them out..
Edited 10/31/2008 11:13 am ET by frenchy
I use a lot of the Deckmate screws sold at HD for a wide variety of applications. They have a combo drive head (bit in the box) that doesn't shred or cam out easily. The heads never ever pop. I would trust my life to them in a 3 1/2in length in a scaffold over nails in a heartbeat. on bigger screws or wood prone to splitting I just flip my hitachi or mikita drill and drive attachment and pre drill and countersink, it only takes a second.
All of this said, I wouldn't frame with screws and I will never ever ever again use drywall screws (note the name!) for anything other than drywall.
Using inappropriate fasteners for the sake of speed, cheapness and your own bottom line is a rip off of your customers.As the song says: "...be good for goodness sake."
There was just a thread here about HD dropping that brand to substitute something cheaper that breaks.
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"I've got about 5000+ 12 x 1/2 inch hardened stainless steel lag screws in my house plus another 2500+ 3/8ths x12 hardened stainless steel lag screws"You hang cabinets with them?
yes, but not that size.
So someone spent $13,000 on screws , frankly I think thats a conservative estimate. Is it a modular home? Are you sure there stainless? Wow
You clearly don't know me.. I'm too cheap to ever spend that sort of money! <grin>
I've got a receipt in my box I should dig it out but I doubt I spent over $800 for all the lag screws. What I did is buy them from a surplus dealer. He had them in his inventory for decades and was anxious to sell them so my offer to buy all his inventory was taken with a great deal of celebration on his part. This occured back in about 1998. (yes they are hardened stainless steell 18/8)
I also bought about 15,000 bd.ft. of black walnut for 17 cents a bd.ft. I bought something like 80 sheets of really thick guage copper sheets 4x8' and paid slightly over $200 for the whole pallet.. (when I later sold the scrap (66#s) for more than I paid for the whole pallet I really felt good!)
IF you look at the pictures of my place you can see all the stuff I'm talking about. Go over to the left side and check out 94941.1 & 85891.1
http://good-times.webshots.com/photo/2086449050046916096jaeCTM
Conscience is the still, small voice which tells a candidate that what he is doing is likely to lose him votes. --Anonymous
http://www.grkfasteners.com/en/RSS_1_2_information.htmHere ya goes - up to 16", tho I've never used more than a 12" one myself
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Better re-read his post...... ""112196.19 in reply to 112196.1 Re: "what look like 12' long screws".I really want to see a 12' screw, ya know?"' That is 12 FEET not 12 INCHES!
They can't get your Goat if you don't tell them where it is hidden.
I figured he was just posting from an 026 keypunch.
Conscience is the still, small voice which tells a candidate that what he is doing is likely to lose him votes. --Anonymous
I stand corrected
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Yup, but the op said 12' not 12"! I said I wanna see a 12' screw. And the truck that delivered it. Ya know?
How about 12 ft DIA. Could not tell from the pictures, but maybe 30-40-50 ft long.http://www.math.nyu.edu/~crorres/Archimedes/Screw/Applications.html
OK. OK. I don't use the alias OOPS for nothing. Obviously the op should have read 12".
The prefab panels were being anchored to the sole plates with screws and the panels were being fastened together with what look like 12' long screws.
Yup, but the op said 12' not 12"! I said I wanna see a 12' screw. And the truck that delivered it. Ya know?
Norman,
It almost sounds like you believe the OP meant 12' screws. Do you really believe that?
Joe Carola
I've got thousands of stainless steel scews holding my house together and it's not because I can't pull the trigger on any one of my 8 nailers or dozen hammers. It's because nothing will surpass the strength and durability of screws..
If you buy Tauton Press's book on framing roofs you will be able to confirm that last statement..
page 129 roof rafters with properly installed nails fail at 208 pounds of force applied. A single 3/8ths inch lag screw on the other hand failed at 2, 783 pounds of force.. 208 to 2783
Yes, screws take more time to install. On the other hand the lag screw in question wasn't properly installed. Instead it was driven in with a impact wrench.
Properly installed that lag screw would have provided even more retention.
If you are properly set up to install screws they can be done reasonably quickly. I bought a three step drill bit and was able to drill pilot hole, shank hole and counterbore hole all at one time. I then lubed each screw with a lubricant designed to aide installation and made for that specific purpose.. Installation was nearly as fast as nailing would have been, once the hole was drilled and the screw lubed..
I needed to use screws to install those panels on my timberframe. Since they had torques head sockets in their heads they went right in without any camming out which is common with phillips head screws.. Some of my panels required 16 inch long screws.. 13 inches to go thru the roof panels and 3 inches into the timbers.. since the timbers were white oak I used stainless steel screws. Those are relatively thin screws, the shank is slightly less than 1/4 inch thick and self tapping.
Okay, Frenchy. I finally pulled out my copy of "Framing Roofs" to read for myself this test that we've all been hearing about for years and years.
"page 129 roof rafters with properly installed nails fail at 208 pounds of force applied. A single 3/8ths inch lag screw on the other hand failed at 2, 783 pounds of force.. 208 to 2783"
You fail to mention that the Simpson H7, according to their test, had a load capacity of 2,726 lbs. So, you can use a lag screw for 2,783 or a H7 for 2,726. That's a strength reduction of about 2%.
The authors stated that the cost of installation of the lag screw is roughly twice of that of the Simpson H7. I know you're going to say that you did your home as a hobby and you didn't care about the costs, but let's face it- most of us care about the cost of things, and if you have two options, one of which is half the cost, most are going to choose the cheaper method.
"Yes, screws take more time to install. On the other hand the lag screw in question wasn't properly installed. Instead it was driven in with a impact wrench.
Properly installed that lag screw would have provided even more retention."
I see no evidence that they did not use a pilot hole on the rafter. Do you have some information not contained in the article?
Finally, I think it's worth mentioning that the authors note "when a metal tie fails, it usually tears in half, but the nail stay put". So, according to this study, we really can't say that nails are weaker than screws.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Yes I do but it's in another source,, a book on wooden frame construction some expensive tomb I bought for definative information to take my plans to the building inspector to get approval without the need for an engineering stamp.. (it worked)
It's sealed up in the attic since I no longer need to refer to it but next time I'm up there I'll get it down and give you the full data..
Here's why properly predrilling a pilot hole & shank hole gains so much more strength.. when you drive a lag screw in without the required pilot hole you tear the fibers apart and start the wood to split.. It's like driving a railroad spike into a piece of trim.. it wants to split! <grin>
By predrilling the wood itself is stronger and splits are less likely to extend and cause failure as that picture on page 126 shows..
However if someone chooses to use the H7 instead of a lag I'll applaud them.. My arguement isn't between screws and Simpson connectors it's between nails and screws.
However the data on install price is skewed..
I tried installing them with a ratchet and came remarkably close to the numbers they used, however when I installed them using a pneumatic impact wrench I was able to run them in in about a minute.. (8 inch, no predrilling)
They don't give 1990 labor rates but It would take me roughly 2 hours to install 100 3/8ths x 8 inch lag screws using an impact wrench. According to their chart I should cost $87.50 an hour in 1990?
Now to be fair I did not attempt to install H7's using my palm nailer but virtually every single Simpson bracket I've ever installed takes me well over a minute.
Looking at the H7 I would expect that to take me several minutes each to install. Would you agree that to be probable? A fast pro like yourself is likely faster..
As for what fails wood or metal does that really matter? Isn't failure failure? If you look carefully at the wood fibers in the failed lag screw connection you'll note that there are no smooth cuts indicating predrilling..
Edited 10/31/2008 12:34 pm ET by frenchy
"Yes I do but it's in another source,, a book on wooden frame construction some expensive tomb I bought for definative information to take my plans to the building inspector to get approval without the need for an engineering stamp.. (it worked)"
I'm not sure what question you're answering, or why a dead guy is involved.
"Here's why properly predrilling a pilot hole & shank hole gains so much more strength.. when you drive a lag screw in without the required pilot hole you tear the fibers apart and start the wood to split.. It's like driving a railroad spike into a piece of trim.. it wants to split! <!---->"<!---->
I understand why you predrill for a lag bolt. I imagine the engineer who wrote the study in FHB does as well. Once again, I see no evidence that the lag screw was installed without a pilot hole. The picture on page 126 gives no conclusive evidence, in my opinion.
"However if someone chooses to use the H7 instead of a lag I'll applaud them.. My arguement isn't between screws and Simpson connectors it's between nails and screws."
You're trying to prove that screws are stronger than nails, yet you reference a study that shows that the metal connector failed slightly before the screw did. The nails didn't fail, so I don't see how that study is germane to the discussion.
"However the data on install price is skewed.."
I see, you can pick and choose which parts of the study you are going to believe.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Sorry, tome not tomb,
Oh I accept what was written however as I pointed out the time is correct for hand installing those lag screws not for using the most efficent method, a pneumatic impact gun..
If you carefully read the text no mention was made of predrilling for the lag screw, and if you look carefully at the torn wood fibers you will see no sign of the even hole predrilling provides, Indeed you can see where the washer punched thru the wood if you look carefully..
If you note carefully where this was tested it might give you a reason why no attempt was made to maximise the strength or speed of lag screws.
Finally the direct comparison was between nails which failed at 208 pounds and lag screws which failed at 2783 pounds.. The use of Simpson connectors is secondary to the discussion at hand..
Edited 10/31/2008 1:13 pm ET by frenchy
Getting back to the subject...the original poster mentioned he saw the recent episode of This Old House where they were flying in prefabricated walls and then screwing them down to the plates. I saw the same episode last night and wondered about it myself - it appeared that the screws were already installed in the prefab wall from the factory, so they just had to run them down into the plates that were installed on site, but I wondered why they didn't just nail them with a gun. There were also some big (maybe 12" long) lag screws used to tie side-by-side wall sections together.
nail's aren't long enough to reach where they need to . Plus nails pull out rather readily compared to screws which are far easier retained.. once you start using Panels to build with you'll understand why..
Years ago when good ring shank nails were available anyone would have had a hard time telling me that screws were better than ring shank nails. When trying to pull one of those nails they would not pull out but might break off. I have seen many screws unscrew themselves over time. Today however the screws have gotten better and the ring shank nails have gotten worse.
the princple behind ring shank is to gain some of the benefits of screws without the difficulty of installation. Screws do not tear the wood as they enter they use the princple of inclined planes to grasp deeply the strength of wood fibers and multiply the are of grip..
Ring shank tears apart wood fibers and hopes the fibers aren't too damaged in the process to retain the nail..
What would be the predrilled size of the hole for a 1/2 inch lag?
Thanks
shellac has a placeBehind the ostensible government sits enthroned an invisible government owing no allegiance and acknowledging no responsibility to the people. [Theodore Roosevelt]
The counterbore is 1 1/2 for the large load bearing washers used under the heads, the shank is obviously 1/2 inch and the pilot hole is roughly 3/8ths of an inch.. I can dig out my micrometer and measure if you want the exact size..
Look at the picture again.
They do mention using a washer under the head of the lag. I would bet most lags could not suck a 3/8" washer down into the hole that was not predrilled.
"Finally the direct comparison was between nails which failed at 208 pounds and lag screws which failed at 2783 pounds.. The use of Simpson connectors is secondary to the discussion at hand.."
If you're making a direct comparison between three 8d toe nails and a 3/8"x8" lag, I think the obvious answer is that the lag is stronger. If they tested a 60d spike against a 1-1/4" GWB screw, the nail would win.What's the point?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Jon
the washer isn't 3/8ths it's hole size is 3/8ths inch.. that's why it's called a 3/8ths inch washer..
the standard load bearing sized washer is 1 inch unless you are using a AN washer (unlikely) which case it would be 5/8ths (with still a 3/8ths in hole)
As for your arguement about using a larger nail read the text.. they said that even 16P nails often split the wood so they predrilled holes for those nails with a 5/32nds drill something they admittted carpenters in the field were unlikely to do..
So larger nails would fail.. finally if somehow you were able to use 60P spikes without the wood splitting there is nothing to retain the nail from extraction except the friction of the nail.. it does not have the resistance to extraction that a lag screw with it's threads 90degree to the direction of pull.
All I'm saying is that they obviously took the time to drill a counter bore for the 3/8" washer, why would you think they would do than and not drill a pilot hole?Once again, comparing a single 3/8" lag screw to 3-8d nails is ridiculous.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
If you pull a washer thru wood you would get exactly that hole
I can't fathom why anyone would use drywall screws for anything remotely structural. If I tear off a sheet of drywall during demo, I often don't take the time to back out all the screws. A few lazy hammer swings snap them right off.
They are seriously brittle.
If you need some wood screws, well, buy some f-in' wood screws.
Bill, I was not suggesting that drywall screws be used for framing. In fact I was not suggesting that screws in general be used for framing. There have been a number of post here regarding the pros and cons of using screw and thought it was interesting when I saw screws being used in the installing of prefab panels. The mention of S/R. screws was a tongue in cheek reference to Piffins disdain for S/R screws being use for other purposes.
I was really interested in finding out if there was any authoritative references available for the proper and use of screws and where they might be applied to better the design and construction we may be evolved in.
I apologize if did not make myself clear and I did'nt mean to step on anyone tail. However my question is still valid.
("Engineers are sometimes the least practical of men, they may be attracted by the difficulties" John Tyler Morgan)
oops,
Yes there are engineering numbers out there for the safe application of lag screws and other screws. I have such a tome myself however it's upstaires sealed in the attic and I don't want to break open the seal, open up the attic etc. to find the data for you..
If it's really important I'd be willing to but if it's simply ideal couriosity I'd rather not go thru the effort if you don't mind..
Most surprising the ultimate rention of such screws has far more to do with the particular wood in question than the screw itself.. White oak was among the best at retention although I'd be interested in looking at numbers for elm as well.
Softwoods such as pine spruce and fir wouldn't have nearly the retention ability that hardwoods will have. However it is easier to drive screws into soft woods..
There is also data regarding the proper use of pilot hole and shank holes and strength gained as well.. If I recall it was in the area of a 20% gain.
Frenchy, thanks for your reply. No, don't break the seal. I don't have a particular or specific need right now. I thought maybe that the screw industry had published a list of what they have to offer and a suggested use of their product even if it was only a marketing ploy. Again, thanks for your offer. Oops.
did you see my links above to discussion opf that subject which also contained links to documentary PDFs ?
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I have now. Thanks. My eyes and my behind gave out before I got to it.