For years I’ve built with only screws. I have a background in theatre, where we used screws for everything – crappy drywall screws to boot! Well, after years of building the platforms I performed on, I’ve found better screws and never really learned how to use a hammer. Well, except to hang pictures and demolition, of course.<!—-> <!—->
Well, the building inspector told me that screws were not approved by <!—-> <!—->Simpson<!—-> for use in their Strong Ties. I examined their literature – sure enough, they say it in big letters – NO SCREWS. USG connectors do allow #8 1.5″ wood screws though. So does a stair tread bracket manufacturer.<!—->
Hmmm.<!—->
<!—->Simpson<!—-> says no – others say yes. Maybe <!—->Simpson<!—-> knows best – I decided to test them out. I bought their 1.5″ galvanized nails, as well as some 8d Bright Common and 16d Bright Common nails (Grip Rite). I then built a test mechanism: One 2x8x14′ attached horizontally to another with a strap hinge. The top board was kept off the ground by 4 legs, the bottom one was a lever that i would use to pull away from the top board – the hinge at the end being the fulcrum.
I then used a piece of piece of 18 ga Simpson strap to go across both boards at differing points, usually 6″, but sometimes 9″ or 12″ from the fulcrum. I would attach the strap to the boards using nails or screws. The screws I used, BTW, were McFeely’s #10 1.5″ round washer head, Grip Rite #8 3″ Primeguard Plus, and <!—->Phillips<!—-> Deck Mate #9 3.5″ screws. <!—->
I’m wondering how you guys in the field might call this.<!—->
1.5″ 8d nail vs. 1.5″ McFeely’s screw – Winner? <!—->
2.5″ 8d nail vs. 1.5″ McFeely’s screw – Winner? <!—->
3.5″ 16d nail vs. 3.5″ Deck Mate Screw – Winner? (Hint – the shear force was over 2500lbs) <!—->
Rebuilding my home in Cypress, CA
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Edited 6/12/2005 1:38 am ET by xxPaulCPxx
Edited 6/12/2005 5:32 pm ET by xxPaulCPxx
Replies
Could you have found any smaller of a font?
I'm wondering how you guys in the field might call this.
Doesn't matter how I think those might turn out. The specs from the manufacturers, and the statements in the code, and the judgement of the inspector -- those count for a lot more than my opinion.
And the reasoning is simple. Big companies like Simpson have a building full of engineers, probably a million or so in simulation software to show them what's what.
And I have a saw and a hammer, a hardhat and a pair of safety glasses.
Although your test fixture is interesting and thought-provoking, how well do you think it holds up against a building full of engineers?
Unless you're the lead dog, the view just never changes.
who ya gonna believe, your own eyes or a building full of engineers?
Remember, engineers built the Titanic, the Tacoma Narrows bridge......
All the simulation software in the world doesn't beat one good hands on test......
Just my two cents worth.....
All the simulation software in the world doesn't beat one good hands on test......
Perhaps you are correct. And that's why we allow some portion of our taxes to be used to crash vehicles and assess the results.
But the point here is that the test being done by the original poster may or may not have anything to do with the specific strengths and weaknesses that must be assessed in order to determine if nails, screws, or other fasteners, are better for any specific purpose.
"One good hands on test" could lead some to think that they have the answer. I prefer to rely on the hundreds of tests -- some hands on, some in a lab, and some simulated -- that an engineer will sign his/her name to.
And here's an example. The original poster has revealed his results -- they show that screws do better. But I've done demolition work where studs were fastened to plates with screws, and others with nails. Getting the screwed studs out is a breeze compated to getting the nailed ones out.
So -- how valid the hands on test is, is a much more relevant question. And that's a big part of the reason for the building full of engineers, and the millions in simulation software.
Unless you're the lead dog, the view just never changes.
All true...I just thought you were a bit harsh on the original poster...
Partly as a consequence of the age old difficulty man seems to have dealing with "science", I think some people (not you!) have the idea that some engineer(s) with the right formula(s) figure out everything, & then we mere mortals follow their instructions...
In fact, theory & practice dance together....emperical knowledge and theory build on each other to give us the "engineered systems" we use today.....
We have this discussion about every 6 months here. Someone has decided screws are better to frame with and doesn't understand why everyone doesn't agree with them.
What the last poster said is right on. What you or I think doesn't mean squat. To be able to use screws, you need indepentent testing and code approvals. That costs big bucks.
So for now, you're stuck with tried and true nails, like it or not.
Although heat-treated wood screws have the shear strength (actually much more than nails in some cases), I spoke to a Simpson person and he said they are not recommending screws because they are not sure how well they will hold up long term, being more brittle than nails.I still think the kinds of nails that I see at lumber yards etc are garbage. Bend and corrode at the drop of a hat. Can only order Maize nails by the crate.I recently had to pull out some 1-1/2" 10d joist hanger nails. Oh boy, scary how easily those babies came out....
"...heat-treated wood screws have the shear strength..."
It's not the strength of the screws/nails that's important - It's the area of the wood they bear on. That's a common misconception.
When I was young, I was put in a school for retarded kids for two years before they realized I actually had a hearing loss. And they called ME slow! [Kathy Buckley]
both
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You are a madman. Can I come over and play? But I think YesMaam gave very sound advice. I would suspect their nails will at least match any of the others you used. Sometimes I get some younger guy working for me with progressive ideas, good carpenters around 30 seem to know everything. Its annoying at times but I think a good sign. I knew everything by 30 now I don't know sh*t. I had one last year that insisted the top of door jambs need not be rabbeted. That's when I coined the phrase. "You're telling me you all of a sudden got smarter than 300 years of carpentry tradition." Said with a smile and he right tone it gets the point across. But today with the progressive fasteners and new materials, glue etc. Maybe thes common sense diversions away from tradition have some merit. I digress. I don't know if you see a parellel. But the inspector probably will fail a strap without the proper fastener.
Next time you want to hang a truck, or blow something up let me know.
Are you testing how much force it takes to break a nail vs a screw? Or are you testing how much movement is permitted before total failure?
Are you testing shear only? Or are you testing shear with some bending force also?
It's not really a question of which one is "stronger" in a particular test (although it is interesting). It's really a question of which one performs adequately in the real world. My understanding is that the use of screws for structural fastening is not permitted because it doesn't take a lot of movement for them to fail.
-Don
You are not as crazy as everyone else is claiming.
Only 50% as crazy <G>.
Some screws have been tested.
http://www.grkfasteners.com/selection_guide.htm
But they have not published a substitue guide showing how many/which size screws can be substitued for how many/which size nails.
Possibly it is too application dependent to do that.
At this point it would still take an engineer, but all of the data needed is there.
"test fixture is ......, how well do you think it holds up against a building full of engineers"
In defense of the original poster, Pretty well - I work in buildings full of engineers, and despite all the millions of software and calculations, there IS NO SUBSTITUTE for testing - why do you think airplane wings are bent hundreds of thousands of time in tests before the plane ever flies passengers?? (edit PS - a truly valid test for screws vs nials would need to include fatigue testing - thousands of cycles at least. )
The is another factor comes into play, and that is skill of the installer or installing the wrong screw (e.g compare an NAS1303 screw to a HF bin special in strength, etc). A loose or wrong type screw is more common than a nail not driven in fully, which becomes a factor in a full up who screwed up on installation type of test. There are many threads on this board about piffin screws not being structural but many still think to use them as such.
In another building related case, a crimped wire connection is actually more reliable (by test results) than a soldered connection or a crimped and soldered connection- why? because of the much more probable incorrect soldering technique being performed by many differnt installers of varying skill levels. (BTW, my own house has soldered crimps as i did all the soldering myself)
Edited 6/12/2005 9:11 am ET by JUNKHOUND
Off topic question.
"Crimped connections stronger than soldered or crimped and soldered."
Learned most wiring skills from USCG regulations for Small Passenger Vessels. I was building inspected boats for charter service and had to wire to USCG specs.
USCG specs say stranded wire and crimped connections only and are subject to random pull tests during inspections. Good system but has a tencency to invite corrosion in a salt water environment. USCG allows solder or silicone type sealants after the crimp is made.
Curiousity requires me to ask if you understand how soldering an already made crimped connection weakens the final connection.
Thanks for any insight.
Jim
Never underestimate the value of a sharp pencil or good light.
Had to go back and read my original post to be sure I did not say something I didn't think I said, so half your answer is that you misquoted me and mixed apples and oranges and different technical attributes.
What I said was
"crimped wire connection is actually more reliable (by test results) than a soldered connection or a crimped and soldered connection"
What you quoted was
"Crimped connections stronger than soldered or crimped and soldered."
Well, soldered is probably always stronger**; however, electrical 'reliable' is a lot different than 'stronger' (sorry Luka <G>) - as for the reasons, they are myriad, including expansion & contraction during soldering giving a lesser electrical weld of the crimp, wrong flux and resulting corrosion, solder or tin whiskers (esp in high altitude or space environments), workmanship, etc. Perhaps the most egregious example personally experienced was a technician who had infomred no one how severe his arthritis was getting - he actually left big enough solder points on connector pins in a mil38999 connector that there was a pin-pin short, only one I've ever seen on aerospace hardware built by qualified personell (tech was qualified decades before the arthritis acute set-in and re-qualed as recently as 6 mo earlier).
edit** unless wrong flux, which can eat thru the wire resulting in no mechanical strengh either.
Edited 6/12/2005 10:49 pm ET by JUNKHOUND
Thanks for the info.
Jim
Never underestimate the value of a sharp pencil or good light.
I meant madman a sincere flattery.
OK, tally so far:
DIRISHINME = pokes fun at my posting skills = dodged the question
YESMAAM27577 = Asks a different question = dodged the question
Boss Hog = Pointed out the history of the question = dodged the question
quicksilver = "I would suspect their nails will at least match any of the others you used" = Votes Nails
Taylor = "had to pull out some 1-1/2" 10d joist hanger nails. Oh boy, scary how easily those babies came out" = Vote Screws
Don D = Asks for test criteria clarification = vote withheld
Bill Hartmann = Pointing out contrary info supporting screws (Thanks!) = dodged the question
JUNKHOUND = Supports actual testing and points out possible test variables = dodged the question
Nails = 1, Screws = 1, Clarification required = 1 Not answering the question = 5.
Well, not a landslide for either side yet.
I wasn't asking what government officials or a roomful of engineers thinks would do better, I'm asking what you think would perform better. I respect you opinions based on years of experience, and I've learned a lot in my readings here - that’s why I'm posing this question to you.
OK, I'll expand on my procedure a little more here. The purpose of my test was to find out at what point one fastener would fail and the other would not under equal circumstances. I do realize that there is a lot of variation out there in screws, as a matter of fact I was very disappointed in one of my screw brands that I tested. But I am testing particular screws in this case. The fastener would be considered to fail the test if it A) broke or B) freed itself from the wood it was fastened to. If the wood failed (cracking the wood in half, for instance) without the fastener being deformed, it was considered a wood failure and a null result.
I also made another test mechanism using 4x8x5' beams to test the longer fasteners, so I could test them at their full depth. Since it was shorter, I had to use my own body weight to apply sufficient force for the tests. I call this the "Fat #### Test" as I weighed myself at 221.5 lbs.
I also did a brief test with toe nailing joist hangers, this test had 2 16d or 2 #9 3.5" screws in the bottom beam and the joist hanger being face attached to the top beam.
Anyone like to change their votes (or weigh in):
1.5" 8d nail vs. 1.5" McFeely's screw (face fastened to 2x8) - Winner?
2.5" 8d nail vs. 1.5" McFeely's screw (face fastened to 4x8)- Winner?
3.5" 16d nail vs. 3.5" Deck Mate Screw (face fastened to 4x8) - Winner?
2 3.5" 16d nail vs. 2 3.5" Deck Mate Screw (toenail fastened through wood filled joist hanger to 4x8) - Winner?
Rebuilding my home in Cypress, CA
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Edited 6/12/2005 1:41 pm ET by xxPaulCPxx
Edited 6/12/2005 5:32 pm ET by xxPaulCPxx
Since you think I dodged the questions, here is what I think would perform the best.
NEITHER!!
For maximum strength limited only by the hanger and the wood, you will need a steel doubler on the other side of the supported and supporting member, thru bolts, preferably 10-32 NAS1303 screws or BACB30NE bolts , and another doubler on the hanger side. Then, adhering to Boss Hog's comments about compression capability of the wood, there may have to be 1/2" or larger dia steel sleeves around those bolts to distribute the compression stress on the supporting beam. Following that, you will need to do shock tests to simulate earthquake loads or overloads and allow for Class I to III hole tolerances and the zipper effect (remember the Kansas City hotel?). Now you are left with yield of the hanger flanges on the supporting member, so you will have to add a bolted stirrup across the top of the beam - whoops, ok there, went beyond the initial hanger failure, so.
My vote: BOLTS, doublers, and compression spreaders.
Edited 6/12/2005 2:00 pm ET by JUNKHOUND
LOL!
Thanks for pointing out the STRONGESTpermutation, but you are still dodging the question. If nails are code and Simpson approved, and I test screws and nails side by side on a fairly basic test using Simpson products, which do you think come out on top?
Rebuilding my home in Cypress, CA
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Edited 6/12/2005 5:33 pm ET by xxPaulCPxx
I think the screws won every time. Now what are your results?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Kinda sorta what Piffin said. With a nail you know that it is or is not incorrectly installed. With a screw you can under or over torque (including breaking or significantly weakening) the screw without knowing it and making the whole install suspect. If I were Simpson I'd require nails.
That said, I use a lot of screws - especially like them in remodel situations where flailing with a hammer causes all sorts of collateral damage. My vote is that screws won the competition. (Disclaimer - I'm a (experienced) HO/DYI; drive all my own screws and don't have to rely on the wide variety of skill/intelligence/focus/sobriety available for hire; also know when I've screwed up (pun intended) and redo it.)
Quit playing games teassing and criticising those who have interacted with you. if you have something to share, go ahead and we can learn from it if the testing was done under any sort of controled manner, but simply having fat albert sit on a stump pole misses a lot for me.I think the most critical fact you are missing in challenging Simpson's recommendations is that when a screw is driven, the torque of the shoulder against the steel of the bracket is one of the most variable and uncontrolable stress points. For a test to be accurtate, you would have specifically torque every fastener, and then to impliment the use of screws in the field, you would have to specify that every installer use a torque control to instal them in the same manner. I applaud your investigatoiry thinking and attempt at the process, but the result is void because the simpson results and recommendations cover the liabilities. Do anythiong else and you can get hung. So why not learn the most basic of carpentry skills and start using a hammer? Screws for sets was fine. You had to take it down again. decks are intended to stay there awhile.
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OK, sorry - I just mean to tease and tickle, not P.O. anyone.
Here are my results:
1.5" 8d nail vs. 1.5" McFeely's screw (face fastened to 2x8) - Winner = Screw
This wasn't even close. I had 4 weights that added up to 33lbs which totaled about 900 lbs of applied force. The nails pulled esily between 15 and 30 lbs. The screws ALWAYS stayed, and stayed straight. Applying more force eventually pulled the screws out of the lumber, again with no deformation of the screws. The nails fail before the wood, the wood fails before the screw.<!----><!---->
2.5" 8d nail vs. 1.5" McFeely's screw (face fastened to 4x8) - Winner = Screw
Same as above<!----><!---->
3.5" 16d nail vs. 3.5" Deck Mate Screw (face fastened to 4x8) - Winner = Screw
While also not even close, I was amazed by some of the results I saw. The first time I ran the test I used 18ga. strap. The screw stayed put in the wood, no pullout, BUT THE STRAP STARTED TO FAIL. I had to keep jacking up one side of the equipment so I could continue to apply force, and the hole just kept getting wider. Backed the screws out and they had a slight bend. The 16ga nails pulled out before I even got my second foot on the beam, and their withdrawl was sudden and dramatic.
I tested again with 16ga. steel strap. Slightly different results - one of the 16d nails actually sheared a head. The wood around the screws deformed enough at the shank (but before the threads) to bend the screw significantly). I was getting ready to see these babies shear a head... when the 16ga. strap started to fail! The #9 nail was with over 2500lbs of shear force was tearing the 16ga. strap! No pullout, BTW, even when the screw was bent at least 30 degrees.<!---->
2 3.5" 16d nail vs. 2 3.5" Deck Mate Screw (toenail fastened through wood filled joist hanger to 4x8) - Winner = Screw
A surprise upset for me, I figured that toenailing would be where the 16d would come through. When toenailed, the shear force was applied at the screws threads instead of the shank - normally a weaker point. This test used only 1200 lbs of force maximum (well, slightly more than that if you factor in the beam weights). The 16d pulled out with me just pushing the beam down with my hands. The #9 screws bent in an "S" until there was no more room to bend between the board toenailed and the beam and then... they held. I had to break them to remove the bracket, but they were still holding.<!----><!---->
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Edited 6/12/2005 5:33 pm ET by xxPaulCPxx
I was voting for the screws.Pretty much have seen the same things in real life, so I am not as slow about using screws as most are.But would you do a bunch of old fogeys a favor and quit using that impossibly small font ?Just type the post in without any font sizing at all. What is default is the best font size. Leave it at default, and everyone has already set thier viewing up to see the default size the way they want to see. If you need a smaller font for your own viewing, go to the bottom of this page, and reset the font size to what you want it to be.That font size of yours has consequences...If people are going to be upset anyway, over what you are writing, they will be even more so, because they can't read the friggen post anyway.Many people will open the post and then just close it without even -trying- to read it.Etc.Like I said, quit playing with the font size when you post, and just let it be default size.
A person with no sense of humor about themselves, has no sense at all.
Thank you for letting me know there is a problem with the font size on my posts, I'll go back and bump them up. Unfortunatly I had to copy and paste a bunch of those, so when they went back in they apparently wrote to the smallest font size - which is what I see every time I type in post. However, it shows up slightly larger in the actual posts when I view them. If you know of a way to change them so the browser resizes, let me know and I will correct them.
Altering previous text sizes now to 3
Rebuilding my home in Cypress, CA
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Edited 6/12/2005 5:34 pm ET by xxPaulCPxx
My vote is for screws. In yesteryears, I once made a contraption involving a hydraulic jack. Actually it tested nails vs. a mortise. The nails failed by bending.
A sharp point about "Piffen screws" -- These are drywall screws. A good tip when you put a 2 1/2" screw thru 2" of material and the point sticks out and catches brand new $20 long-sleeved, two pocket work shirts, is to give the protuding tip a sharp sideways wack with a Plumb hammer. The metal seems to be brittle and will snap off. A file will not dull the needle point which gives an idea of the drywall screws hardness. My current preference is for sheet metal screws, preferably with the hex head. Use the sharp point type for wood.
The points about following mfgr's instructions is valid to pass inspections is valid but perhaps Simpson should investigate screws since they are easier to install in certain situations.
~Peter
Yep, I've done that many times myself. But if you strip the phillips head 1/2 in or out, you can just whack it off with a quick swipe of your battery pack - so it's almost like a feature!
Funny, after seeing "piffen screws" mentioned here a couple of times, I googled them. All I came up with was quotes from Piffen!Rebuilding my home in Cypress, CA
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That is strange. I googled the phrase and got no results found. but if you use the search feature here, you will find that others use the term far more than i do, since they invented it.Wanna know how and why?
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Excellent !Now, if you personally need to see a smaller font than what is the default, scroll to the bottom of this page. You'll see a box labeled "text size". Just choose the size you want, and it will always be that way for you, when you are logged in.I kinda figured that the stuff was written elsewhere and pasted in here. That is a common reason for funky font sizes.When that happens, paste it first into an ordinary text file, then copy again, and paste here. The ordinary text file paste will get rid of the font sizing.The beauty of the default is that everyone can then have the font size they can see best for themselves. When it is forced to be something other than default, it can be way too small, as your was, or way too large. (We've seen a few of those as well. LOL)
A person with no sense of humor about themselves, has no sense at all.
I find that even "ordinary text" pasting produces a funky font, for some reason.
Thanks. Looks like he changed it while I was responding. came back around and there it was even before my responce fully loaded up!
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I'll start building houses with screws - no nails - as soon as I start working with customers who can afford $400 a square foot homes. And really, even customers who can afford that would rather have BIG square footage and more bells and whistles on million dollar lots...
This whole building with screws kind of thinking is the type of thought process that causes DIY projects to take years to complete and end up way over budget. Admittedly though, I might look at it a bit differently if I were living right on top of a significant seismic fault. Matt
"when a screw is driven, the
"when a screw is driven, the torque of the shoulder against the steel of the bracket is one of the most variable and uncontrolable stress points. For a test to be accurtate, you would have specifically torque every fastener, and then to impliment the use of screws in the field, you would have to specify that every installer use a torque control to instal them in the same manner. "
Very good point - Thanks for pointing that out for me! I'm very familiar with using correct torque settings from rebuilding a couple of engines so that makes sense to me from an engineering standpoint.
However, I'm applying that same criteria to nails I come up a little short. It would seem that nails, when applied in the field, would at least require control of depth, ensuring that the plate of the tie was flush with the wood, and the nail head was flush with the metal plate. But here is an example of what I actually see:
Here I see coated nails that are not fully driven (not sure if they are 8d, 10d, or 16d). The top strap has a 1/2" gap, the post ties nails are all about 1/4" out. I'm not sure if they weren't driven fully or if weather caused them to pop out. I just see these nails, and know that these are code and Simpson approved to help hold my 2nd story up in the air. Even with a screw not being torqued enough, there would unlikely be this much gap. And if it was over torqued, you're more likely to strip the threads you made in the wood making it a very hard nail.
Rebuilding my home in Cypress, CA
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Edited 6/12/2005 5:07 pm ET by xxPaulCPxx
Edited 6/12/2005 5:33 pm ET by xxPaulCPxx
Hey! I didn't give you permission to post pictures of my work!
Is that a picture on a job or one of your tests? I can't tell what angle I am seeing what things happening.Now you are starting to get the start aof a good discussion going, but is there any way to get uyou to use the standard formating and type size? the lettering you have chosen is so small that it hurts to try reading it.
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That picture is of the top of a 4x4 that holds up a 4x12 nominal beam that forms the long edge (33') of the 2nd floor addition to my home. 2x12x16' floor joists sit atop that - on the other end they sit attop the outside wall of the house. The 2nd floor addition is entirely over the outdoor patio.
Those nails were driven in 1982, when they built that addition. That Simson connector is a BC4, I believe - which must mean those are 16d nails.
I left the text default size on this post - no pasting back & forth, I hope it looks OK.Rebuilding my home in Cypress, CA
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My suspicions were true.
Well, that's a pretty cool test IMHO. Pretty cool car spinning contraption, too! (How'd you find the exact center of gravity on the length-wise axis, though?).
I'd vote for the screws--just because I think a room full of (government approved) engineers will almost always find the wrong answers..
You ought to check out the Coral Castle down in Miami. A 4-foot tall dude built this thing out of 2-3 ton sized coral blocks he cut, excavated, and positioned...by himself..only at night under a full moon. There's a revolving door there that weighs a couple of tons which he's got perfectly balanced on a coke bottle so it spins with one finger.
The whole castle was built without ANY simpson ties or...nails. Or anything else which might connect the blocks. And no building codes were followed at all. I think it was built about a hundred years ago. I'ts still there. He's all gone.
Thanks! I balance it by attaching the brackets to the front and rear, then using a jackstand as the balance point on the bracket and moving it back and forth until worked out right - marked it and welded on the axle.
I realized later that the with a driver behind the wheel, the car would be perfectly balanced down its center axis... as long as you had the Right Hand Steering that England and Japan have. Nice bit of engineering!Rebuilding my home in Cypress, CA
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I'm gonna go out on a limb here. Someone suggested screws wont pop as much as nails when lumber dries out. From experience I can say thats not exactly true. Screws will pop.
When wood dries out the forces of its contraction are not any different with a screw driven into it. The measurement of a popped fastener from the wood surface to the underside of the fastener head is equal to the size difference of the wood at its highest moisture content versus its size when it reaches its equilibrium
With that information ask yourself which would you trust with your life with, A harder screw inserted all but 3/8 of an inch or a softer nail inserted all but 3/8". I would bet the screw would snap off and the nail would bend but still hold
You know, that's what I thought too. Then I tested it and found out that is a false assumption. BTW, we are talking about modern wood screws - specificly the ones mentioned at the beginning. I did some rudimentary tests on the 3" #8 Grip Rite Primegard Plus screws, but found them lacking. Some screws are better than others, I will attest to that!
If a nail is ALREADY 3/8" out, it basicly has a running start on getting pulled out. The screws have some solid shank still left in the wood, but also still have all their threads in there to keep that shank in place, with the wood producing a soft shoulder that allows the shank to bend instead of shear as it might if embedded in steel - Hypotheticly at least. My tests showed the nails more prone to shear than the screws. I sheared one 16d nail and tore the head on another. I sheared the head on one 3" #10 McFeelys screw (the longer brother of the 1.5" ones), but that was at force levels much much higher than I could even approach with the nails. That was the only one that broke, and it wasn't being tested at a level comperable to the 8d nails I was comparing it too.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Mav,That "pop" is not actually a pop in the same way most seem to mean it to be.The nail has not popped out of the wood, the wood has shrunk in size.What was 1-5/8 thick because it was swollen with water, has now become 1-1/2 since it dried out.The nail is embedded in the beef of the wood itself. It stays basically where it is, and the wood below the head shrinks back.Most of the nail is still exactly as stuck as it always has been. Very little of the wood actually pulls away from the shank of the nail down inside. That wood was compressed by the nail as it was driven in.Same with the screw.In this case, I would trust the screw much more than the nail in a pull situation. But in a shear situation, I would trust them almost equally, once the gap gets over 1/8 of an inch. That is, if a good quality screw was used. A piffin screw would not get my vote in any of these situations.Also... nail or screw, screw or nail... Doesn't matter which you use... If/when you see a bad situation happening with the plates, common sense says fix it now. Don't "rely" on it to last longer because it is a nail or a screw, whatever your choice is.And when it comes to that "fix"....Drive those nails in again, and they lose some of the grip they have had. They -will- work loose again very easily. But screw the screws down further, and they still have exactly the same grip they have always had.Over the years I have used beauceau screws to fasten plates and joist hangers with. I have never seen a failure on one done with screws. But I have seen several pulled and bent nails. Plus, try to demolish something put together with screws... without taking the screws out. The structure that was nailed, is tons easier to demolish with brute force. The one done with screws though... take those screws out, and you can even save a lot more of the materials as salvage...That's real life, empirical evidence. Based on simply paying attention. Over many years. And not being afraid to do something that my common sense and experience told me was safe, regardless of what the room full of engineers claimed... Doesn't make it more or less useful than anything else written in this thread. I do trust the screws more. Besides, it is easier to place the hangers, in difficult situations, if you use screws. And if you screw up, (no pun intended), you can just move it and fasten it again.I have even been known to place them with a couple of screws, then nail them in place. LOL You can get them snug with the screws, and not have to try to hold them snug and pound a nail at the same time.Leave the couple of screws and you have added pull resistance to your nailed plate.
A person with no sense of humor about themselves, has no sense at all.
<<The nail has not popped out of the wood, the wood has shrunk in size.
thats what I was getting at. the nail driven into the heart of a board is still in the heart of the board when the wood shrinks.
Saying that a nail pops is like saying the sun rises. It doesnt, it only appears that way
That car "spinner" is REALLY COOL! I was falsely impressed with my spinning solid doors. I assume you used screws in your end brackets.
I used to do "glue tests" but never elaborate screw/nail tests like you, but I was sure from reading your first post the screws won hands down. Sometimes we use a wench to rack i.e. a sagging old garage and you quickly learn to use screws.
To him who only has a hammer all the world is a big nail.
Hey, I like your door rotisserie. I think I'll rip it off! I've got a ton of doors to paint... sometime.
And you bet I only used screws. Didn't want 1/2 ton of fun dropping on my foot unexpectedly!Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Paul,Just read this thread. The founder of Velux, the Danish roof-window company, was told by the experts (in the late 1940's when Velux began) that all roof windows must inevitably leak. He proved them wrong. The company motto is something like, "One experiment is worth more than all the expert opinions." I'm sure it is on their site, but this is from memory.I think there are a host of reasons the Code prefers nails to screws, including:1. Tradition. "It has always been done this way."2. Technology. Older screws were weaker/more brittle/less uniform than modern screws.3. Verification. There is less to be done wrong with a nailed installation than with a screwed installation.4. Redundancy. Since the nails are weaker, more of them are needed, and so the risk is spread over more fasteners, tending to more overall reliability.5. Terrible results with Piffin screws. Left a bad taste in the craw of Code authorities, resulting in a mindset of, "We gotta be sure THAT never happens again."I am surprised you did not test the Simpson Strong-Drive #8 by 1-1/4" screws. They are rated by Simpson's hall of engineers for respectable loads. Too bad they offer nothing between that and the 1/4" Strong-Drive lags.I do remodeling, and I agree with the poster who noted the lack of collateral damage in older structures when using screws. The codes need to catch up to the technology so that we have more legal options in our quest for construction excellence.Thanks for introducing this topic.Bill
"I am surprised you did not test the Simpson Strong-Drive #8 by 1-1/4" screws. They are rated by Simpson's hall of engineers for respectable loads. Too bad they offer nothing between that and the 1/4" Strong-Drive lags."
Funny you should mention this.
I once compared the 1 5/8" Simpson hanger screws to Deckmaster 1 5/8" screws. Both were plenty strong in shear, but the Deckmasters had better tearout resistance.
Hmmm, interesting... I just read this on the Simpson FAQ:
Q: Can I use nails other than what you have specified? How about using screws instead of nails?A: Some of our connectors (generally straight straps and face mount hangers) can be installed with alternative fasteners but usually with reduction in load capacity. Please refer to the Simpson Strong-Tie catalog or <!---->this chart<!----> for a list of viable substitutions. As for screws, because of their smaller shaft diameter and shorter penetration distance they usually have lower shear capacity than common nails. This is not to say that you can not use screws with our connectors. Just keep in mind that there is going a reduction in the published load values, and if this reduction is acceptable, then there should be no problem using them.
I think this is going to help me make my case with the inspector.
I never really took the Simpson screws seriously, as they were phillips head instead of square drive. I'll do drywall in phillips, but I'll stick with being square for everything else if I can get it!
Interesting note about pilot holes and nails... though in the test with the toenailed 16d, I did predrill them with a 7/64 bit to prevent splitting - same as I did with the screw. It still gave quite easily - however I did not drill the pilot hole the full length of either fastener, only about 1.5 inches.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Thank you for doing the testing. While your tests are far from extensive enough to be conclusive, they're very helpful nonetheless.
What I would appreciate is the OPTION to use screws when they're structurally adequate, rather than having a code tell me to use nails in every occurrence. Screws have lots of benefit when what you need is withdrawl resistance rather than mere shear strength. There are lots of occasions during framing where a little more withdrawl resistance than offered by a common nail would be very helpful and would lead to a better job.
I certainly wouldn't replace nails with screws in all locations- doing so would be pointlessly slow and expensive. I bought a palm nailer and it makes the installation of hanger nails a much more pleasant proposition. And although they seem silly, using those little 9ga x 1.5" sinkers eliminates the fight with the inspector.
I've had lots of recent experience with setting up and taking down one-off concrete forms. With the local building supply place pricing duplex-head nails at MORE per piece than #12 x 3.5" deck screws, it was a no brainer as to what to use for the job. My lovely little Makita 12V impact driver made the use of #10s and #12s a much more enjoyable proposition. But what surprised me is the brittleness of the screws. I lost count how many I snapped. So brittleness is not just a feature of drywall screws, and hasn't been eliminated from "modern" screws either.
If we're discussing pull-out resistance of nails vs screws.... How many people predrill holes for nails?
How many know that predrilling increases withdrawal resistance for nails?
I love this arguement!
Screws always win if they are properly installed and tightened.. That's why my home is assembled with mostly screws. (well, lag bolts are screws)
Fine home building actually did back to back tests and I've often stated them here.. Piffin hates me because I have done it so often, but if you get a copy of Tauton press's book on roofing page 126 thru 129 you'll find that a simple 8 inchx3/8ths lag screw had a load capacity of 2783 pounds compared to Simpson's H7 connectors of 2726 pounds.. If you properly install the lag bolt instead of just driving it in you'll have enough capacity to beat the top H6 Simpson connector of 3,150 pounds..
In my case I used 12 inch hardened 18/8 stainless steel 1/2 diameter lag bolts (screws) in holes that had the proper pilot hole & proper shank hole. In addition I used them in White oak with much higher pullout numbers then the pine tested ...
Since each of my rafters has 11 lag bolts in it, some in shear and some in tension my calculations indicate that it will take at least 11,000 pounds for my rafters to fail..
In addition the SIP panels are installed with the approved screws that just look like big ol' long sheetrock screws.. (my longest are 14 inches) every 4 inches per instructions..
On the outside of that I have these black walnut timbers lag bolted into the inner white oak timbers. In short my walls are stronger than the average railroad bridge! (not a single nail involved)!
Back from the dead and ready to party!
TickTock asked me to update this thread with the pics and videos
While I cannot update my original post, I can reply to it with the updated pictures. I'll get to that, but for now I'm reviving it so I'll see it again.
I will also update with the new Simpson SD9 and SD10 screw information.
So alot has changed from when this was first posted back in 2005: Namely, Simpson came out with their SD9 and SD10 series screws that were specificly designed for their connector hardware. SD9 is a #9 screw, and SD10 is a #10. Both series come in 1.5" and 2.5" models. Cost is $.09 to $.13 per screw in quantities of 100.
http://www.strongtie.com/sdscrews/index.html?source=hppromo
One of my favorite quotes on that page:
"The single-fastener load capacity of the SD9 exceeds the capacity of a 10d common nail, while the single-fastener load capacity of the SD10 exceeds that of the 16d common nail"
Both screw series have a 1/4" hex washer head that has nubs at the bottom to help seize rotation at the snugged tight point. The advantage of the hex head is that it not only can be easily held securly with a magnetized bit and started with one hand (unlike a philips or star drive), but in a pinch you can use the hex shank holder on your impact or drill driver itself without the need for a seperate bit. This is also usefull in very tight spaces.
I found these screws very easy to work with, and I'm going to switch over to them for all my connector tasks.
One thing to keep in mind with these - Simpson approves a SPECIFIC screw for a SPECIFIC connector. Look on their site for the published list of what screws matches the connector you are using.
http://www.strongtie.com/ftp/fliers/DIY-SDTPAD10.pdf
Another change, The Phillips Square Driv screws that were initially only sold at Home Depot are now available at Lowes. Home Depot had a slightly different star drive variation of these screws. Yesterday i say that the Square Driv were back in HD, so who knows what is going on there.
Thanks again!
OK, here is a small video of one of my tests - I appologize for it being low quality but I have no where to host a larger file. This was of the toenail test I did using a HUS26 Hanger using both 2 16d and 2 of the Phillips Deckmate #9 3.5" screws.
You will see equal loads applied, and what the fasteners look like afterwards.
BTW, these test are repeatable - fell free to try them out on some scrap lumber!
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
EDIT - video lost
Here is a new test - Shearwall!
Distance from pivot point was 15", so the applied force this time was about 1000lbs.
I used 15/32 OSB (some scrap Radent barrier I had) and a total of 4 of each fastener: 2.5" 8d Bright Common vs. Senco 2" #8 Duraspin coated screws.
(You can see their code status at http://www.icc-es.org/reports/pdf_files/ICBO-ES/6068.pdf)
Here is how the nails faired:
The nail that looks like it's coming from the bottom of the beam is actually still attached to the OSB. The tip of the nail pulled out then went under the edge of the beam
The screws did not fail... I won't post a boring picture of screws staying in place and the OSB not giving way either, but here is what all 8 of the fasteners look like, side by side:
You can see a little bend in a couple of the screws. All the nails were obviously deformed by the force.
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Edited 6/14/2005 8:09 pm ET by xxPaulCPxx
Edited 6/14/2005 8:13 pm ET by xxPaulCPxx
Nails vrs Screws
1. Did you ever get that CRX done?
2. Thanks for taking the time to do the test. Honestly i never had a doubt in my mind that the screws would win hands down every time, and i apprecite your attention to detail in calling attention to the "types" of screws used as various hardness=brittle etc. I think your engine experience helped you there.
i myself get facinated with the incredible material science when it comes to those recipies for metal compositions and heat treating , annealing, quenching, etc etc. Incredible! Think of valve springs dia, high tension rates without being so brittle they break for 8000+ rpm engines that need their valves shut quick with steep camshaft lift heights, or connecting rod bolts that can hang on to that reciprocating assembly.
3. i wanted to mention a little piece of construction i was doing where i needed an interior stud wall office in a building. I needed to be able to hang shelves anywhere in the office enterior, but also,. as it was a restaurant, various shelving attachments also might not always be able to catch two OC's of the 16" centers, so i decided to use 1/2 OSB inside and out for greater versitility before we hung the drywall.
We used screws only, apart from the gun nailed floor sill plate. We screwed the inside OSB's and when we just about finishing up screwing the outside OSB's my buddy and i just both just stopped and looked at each other at how damn incredibly stiff that wall got like "instantly", cripes, thats almost like an i-beam every 16 inchs wall!? (this was before TJI's or Truss joists became popular)
From that moment on i swore if i ever stick built by own house you can be damn sure i'll buy the extra OSB for all the interior walls (externally insulated plywood exterior of course to avoid those worrisome dreams at night of any exterior leaks/ sorptive issues with exterior osb) and just use all good Screws and be happy to deal with a hastle any additional future cuts of both dry wall and osb like specific additional wiring and so forth beyond the origional plan, just for the peace of mind i'd have.
Heck, with the right corner posts and cap plates with braces, top plates and rafter work, i swear for just a 20-25%% additional materials cost you could have a house that a tornado would pick up and land you in OZ right on the old witch before it blew apart.
So what is the word on the Simpson screws? Are they considered "legal" most places?
read post #57.