subybohn

I know this is a can of worms -- and I have read the postings from Nails vs. screws...

But I have a problem.... Simpson Strong-Ties LUS28Z face mounted joist hangers...

According to their web-site, this hanger can really carry a good load, as long as it's installed properly.

I've noticed that if the Hanger has an "S" in its name, it's a hanger in double shear and their web-site specifically says I cannot use 10d x 1-1/2" Joist nails.

AND if I use a 10d x 1-1/2 joist nail in the header, I have to multiply the load by .65 (or I have to reduce the load it can carry by 35%).

To maximize the load these hangers can carry, I have to install an equivalent fastener to a 10d common.

I am only using the hangers along the house and with the header lagged into the rim board; I have the needed 3" for the 10d length....for both the header 10d nail and the joist 10d nail.

However -- their specs says the equivalent to a 10d common is 0.148 x 3"

I am using treated wood -- and the hangers are not stainless steal -- so I cannot use stainless steal fasteners.

I can find 10d hot-dipped galvanized in a Box Nail, but not a 10d hot-dipped common nail.

If I use a box nail, I have to go to a 20d to achieve the 0.148...but their 4" long...and will stick out an inch....

I've seen the "deck Nails" that are really just spiral 10d - which in their 2003 catalog said I could use without a reduction -- but have been removed from their 2006 Replacement Nail table....butd I can't find the specs for 10d Deck nails nor have I found them on store shelves...

The Nail vs. screws discussion stated if screws are not over driven "in a nutshell, when comparing nails to screws, screws will prevail in every instance."

HOWEVER, the City of Des Moines (Iowa) is not allowing me to substitute 3" Deck Screws (which are not drywall screws) for the 10d common -- and are requiring me to use the 10d x 1-1/2" joist nails -- because "that was what they were designed for" --- and I can't get them to see the joist nails cannot be used with the hangers I have...

HELP -- What am I going to do?

redwood

Simpson makes a longer hanger nail, N10. Your decking screws will not have anywhere near the shear strength.

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neolitic

You can use stainless with gavanized.
Beyond that, you lost me.
Are you sure you're reading the chart properly?

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BuiltByMAC

Your local lumberyard should be able to order these for you...

Mac

subybohn

I'll order them from my lumber yard... THANKS

BUT now, how do I get the city to let me use them instead of the "10d - 1x1/2" joist nails" they believe were designed specifically for the hangers?

And why do people think screws do not have the shear strength that nails do?

Screws are made from hardened steel -- which is stronger than nails -- capable of more shear...

Proof -- take a wire cutter -- cut a 10d nail with it (shear). Now try cutting a 3" deck screw -- depending on how good the wire cutters are, you may ruin the cutters before you get through the screw.

"Bending" is not shear....

As long as you do not "over drive" a screw -- a screw will always be stronger than a nail, have a better hold than nails .... but more time consuming to put in than nails.

It's only when you over drive a screw you put the screw into tension and the screw will break before it pulls out or "withdrawals"... but again, a nail will withdraw before an over tightened screw breaks.

Manufactures of the Deck Screws want you to install deck screws while wood is still wet and not to over drive them -- so as the wood dries, the wood shrinks. If you use screws on dry wood -- when the wood swells, it will put tension on the screws...or pull out the nails, which ever fastener is being used.

I've also hear of building the deck outer rims with wider boards and placing a 2x4 along the bottom forming the 1-1/2" ledge needed for the joists and just using the fashioned tow-nailing idea....

A wider Ledger board will still allow you to lag it to the rim board and gives you an area to secure the 2x4 to.

And if you are resting your joists on a beam, by using wider boards, the beam can fit up into the area with the side joists lagged into the beams ends.

Has anyone done this type of a build yet?

neolitic

What you are talking about is
a true ledger (forming a ledge
on which the joist rests), yes
it works fine, yes that is what
we did before galvanized hangers
were common place.
Nearly all houses were framed
that way from the introduction
of dimensional lumber until WWII.
Will your building authority approve
it?
Doubtful.

I can't picture the Simpsons you're
talking about, I mostly use USP as
they are more readily available for me.
With the USP there are holes for
toe-nails (10d) and the rest are for
the 1½" hanger nails.
Is this maybe the contention?
A double hanger for a header on
a doubled joist is what comes to mind
for all 10d.

Where are you?
Even the Box stores carry galvanized
commons here.

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neolitic

Oh, the screws are stronger in withdrawal,
but the softer steel of the nail is actually
better in shear...given equal diameters.
I'm thinking you have to go to a #12 screw
to equal the shear of a 10d nail....
or something like that.

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subybohn

I am in Des Moines, Iowa, and had a great discussion with the lumber yard -- they finally realized they were selling the wrong length of nails with the hangers -- but that was what the contractors are installing....

We also have Menards -- and their Fastener sheet shows they sell "deck nails" but haven't been able to find them -- no "demand" for them.

Yes -- if anyone can help me get a building inspector to understand the difference between 10d x 1-1/2" and 10d x 3" AND how to read a Simpson Ties Catalog -- PLEASE HELP ME!

They are also requiring the 8d x 1-1/2" nails to be used with the Hurricane ties that specifically state to use 8d x 2-1/2"...

As far as softer -- yes, nails will "yield" and screw will not.

A nail can yield a little as long as it won't pull out....that is why each size needs a length embedded into the wood -- 10d needs 1-3/4" and is why you have to take a reduction in the allowable loads when you use them.

If you don't exceed the load, the nail will not yield, nor will it pull out...

And yes, if I used a WOOD screw, I would actually need a #7 for the 0.148 but for 3" would need a #16 (.268) - hence why Simpson Ties sells an 1/4" (0.250) x 3" WOOD screw.

There isn't a lot of information on Deck Screws.

Simpson's table list 10d commons as 9 gauge -- so my local lumber yard sells a 9x3" Grip-Rite Exterior (Deck) Screw .. They tell me the 9 means the gauge... but I'm not sure, I haven't been able to verify this yet... However, they fit nicely into the LUS28Z hangers...and threads are not in the hanger's shear plane.

So are "Deck" screws - wood screws or thinner Lags screws?

Lag screws common sizes start at 1/4" and are widely accepted to be used with decking for a hold better than nailing especially with expanding and contracting wood (wet & dry conditions).

Where do I find the specs I need to see if there is a differences and if exterior "deck" screws truly should not be used in hangers?

redwood

First off, I beleive the 10d refers to the length, not the diameter. A 10d is 3" long. You cannot have a 1 1/2" long 10d in any nail.

2nd off, a like diameter screw will generally shear much sooner then it's nail counterpart. Assuming like materials. Now, if you are discounting the threads in the diameter, that might be something else.

When we tear off decking and it leaves screws or nails, usually a couple wacks with the hammer and the screw breaks. Not so with the nail, unless it is rusted.

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jarhead0531

Well the simpson site has great info on it that should be able to help. This lists the nailing schedule for that hanger. This explains exactly what they mean about types of nails. Either way you should keep a copy of Installers Guide in your truck.

As for screws vs nails. Nails will always have better strength in shear, screws will have better pull out strenth. Screws are in fact harder, which also means brittle, and more like to break in shear situations. Screws that are designed to be strong in shear are heat treated for strenth then tempered for toughness which actuall softens the metal. Deck screws probably don't go through that process are too brittle.

HTH,

Barry

neolitic

I know how you feel about that.
Sometimes 1½" hanger nails are
9ga, sometimes .148",
and sometimes 10d....

ADD: I see Jarhead beat me to it.
From the USP site:

Attached Images

 

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subybohn

Awesome Installation Guild book! It definitely reinforces the correct nails (and sizes) to be used with the application of Simpson Strong Ties.

I can agree with you if the decks you were taking apart used the old galvanized screws (used before anyone realized the reactions between the screws and treated lumber).

And/or if deck screws were improperly installed causing the screw to “stretch” or develop tension beyond its design when the treated wood swelled or expanded.

They key is proper installation...AND proper coated screws.

This tension is only possible when wood is being secured to wood and either the screws was fastened to tight, or the “neck” of the screw is not long enough for expansion movement (threads are not clear through the first board).

Attaching a metal hanger onto a Header should not be a factor, for the metal will not swell or expand.

Is there a web-site or any documentation to show tests results measuring shear, bending, tension, compaction, torsion between 10d and 3" exterior (deck) screws or has no one actually done this kind of testing yet?

neolitic

If you don't already have it,
this might help you out....
http://www.fairfaxcounty.gov/dpwes/publications/decks/

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subybohn

I can get USP Connectors from Menards and do use them – but I thought since I was on a Professional sight, people would be more familular with Simpson Strong Ties.


So USP’s JUS26 hangers are the same as Simpson LUS26 hangers and the “S” also means they are in double shear (Notice Ref. No. Column)

But both need the (4) 10d = (4) 10d x 3” and not the 10d x1-1/2”

To use the 10d x 1-1/2 in the joists I would need to use the JL26 but notice the difference in the allowable loads.

subybohn

I tried to include a snap shot of the PDF... but it didn't take -- and I can't post URL's until I do 15 postings so -- take out the spaces:

h ttp://www . uspconnectors.com/pdf-full-line-2007/jus.pdf

How are you posting the graphics?

And no, I have not seen the web-site -- and am downloading it now.

THANKS

subybohn

WOW -- talk about details -- but they also show the LU2X (JL2X) hanger not the LUS2X (JUS2X)....

Do you follow the 2006 International NEW Residential Code for our risers can only be max of 7-3/4".

We also don't gap our deck boards -- for after we install them wet they dry/shrink and develop the 1/8" needed gap...otherwise the gap ends up being to large.

This deck guideline almost looks like they are designed for high wind or hurricanes..

In Iowa, we don't design for tornados -- for a deck cannot be designed to withstand one.

But I did notice the "General Notes" say the nails have to be ring shanked or annular grooved which may say you can't use 10d common in the hangers -- and I don't think those 10d-5GDG are annular grooved....so do you use screws in your hangers?

This is getting REALLY interesting....

neolitic

You don't realize how funny
it is to ask me computery questions!
That was just a screen shot, and you will
see the attachments button when you have
enough posts to do attachments (I think).
We don't have to follow the 2006 code yet,
but I always try to build above code anyway.
That link is just a good guide to the most
stringent code around...and a good reality check.

I just use hanger nails for hangers, ring or screw
shanks for attachments and doubles, etc.

Not necessarily building for tornadoes, but uplift
is a factor, especially on second story decks.
There is wind lift.

Lastly, around here Menards does carry
Bostitch hot dip hanger nails, as well as
most any regular galvanized ( I just bought
a 5lb box of 10d common galv. a week ago).

Oh, pretty much the same as you on spacing
wet TYP, the shrinkage takes care of the gap.

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Alwaysconfusd11

10d is always 3". Where do you see 10d 1 1/2"?

No.

If you dont exceed the load on a screw it will not yield either.
Deck screws are just steel screws, that resist corrosion, are very sharp, haver alittle extra material at the underhead fillet, and have a shallower degree on the threads.



Some screws may be "harder" than nails, but hardness also leads to brittleness. Hardness is a specific physical property of a material to resist shape change when a localized force is applied. What you are probably referring to is toughness, which is how much energy a material can absorb. You start talking about yielding, and strengths, but are pretty far off. You really don’t need to get into any of these principles though. The majority of screw failures are because of the cyclic nature of structures, especially decks with the foot traffic and expansion and contraction due to weather, and wind, and the list goes on… Most screws fail at the thread start closest to the head. It is called notch failure (notched-specimen) because there is a stress concentration there. Think of anything made of metal, how often do you see sharp corners where to planes meet? Just about never, filets are added because there is a concentration of stresses at sharp angles. A true 90 deg corner has almost infinite stress.

neolitic

[Freaking screen shot should be here]
Crap!
I'm on a different computer....
See post #11, or Jarhead's nail guide link.
Apparently it is common for hanger nails.
I even found an old box in the garage
that is labeled so.

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Alwaysconfusd11

Im not sold, just becuase Simpson says it doesn't mean it is correct. It seems they call it a N10 as well.