Almost every attached deck needs joists hangers, attached to the ledger boards with fasteners. Holding the joists in place, supporting the deck and your fantastic outdoor space. I have attached hundreds of deck joist hangers using both screws and nails. Both have their advantages and disadvantages.
There are four things to consider with deck joist’s hanger fasteners, costs, including material and installation. Structurally it is crucial to evaluate hanger fasteners shear strength along with corrosion resistance.
The best fastener is one with the best combination of these four qualities. Unfortunately, you cannot have all four. There are trade-offs between fastener options. One may stronger but will cost more or is more challenging to install than other options.
So, first, the best overall hanger fastener, then the best in the individual strengths.
Best Deck Joist Hanger Fastener Overall
Is #10 1-1/2 x 0.148″ Hot Dip Galvanized nails. The oldest and most common hanger fasteners. Simpson makes them, therefore, compatible with Simpson deck hangers, the most common deck hanger. These are the best overall fasteners for these reasons. #10 hanger nails have the highest shear strength of the fasteners I compared at the lowest price.
If you want a robust fastener that will last for years to come but pay the least. Hot Dipped Galvanized Hanger Nails is the way to go. Simpson #10 hanger nails are protected by being dipping in hot zinc, galvanizing the metal.
Lowest Costing Deck Joist Hanger Fastener
The cheapest fastener is also the simplest, #10 1-1/2 x 0.148″ Hot Dip Galvanized nails. Simple dowel design attaching the hanger to the ledger, for less than 10 cents a nail. They are no approved fasteners that will cost so little.
Even roofing nails, which you should never use for fastening hanger, are only a cent or two cheaper. Not to mention will fail sooner as the metal is not designed to support a deck’s weight.
| SMOOTH-SHANK CONNECTOR Nail 1-1/2 x 0.148” HDG | USPStructural Wood Screw #9 x1 3/8” | SD CONNECTOR Screw #9 x 1-1/2” | SD CONNECTOR Screw #10 x 1-1/2” | SDS HEAVY-DUTY CONNECTOR Screw 1/4 x 1-1/2″ | |
| Unit Cost | $0.08 each | $0.24 each | $0.10 each | $0.12 each | $0.50 each |
| Case Cost | $9.19 (120 pkg) | $11.79 (50 pkg) | $9.97 (100-Pkg) | $11.82 (100-Pkg) | $12.35 (25 pkg) |
Even with double shearing nailing, which Simpson
requires a minimum 2 ½” (64mm) fastener. Galvanized framing nails cost the least, being the most economical option for fastening joist hangers.
| USP 0.148-Gauge 3-in Hot-Dipped Galvanized Smooth | USPStructural Wood Screw USP #9-12 x 2 7/8” | SD CONNECTOR Screw #9 x 2-1/2″ Mech. Galv. | SD CONNECTOR Screw #10 x 2-1/2″ Mech. Galv. | HEAVY-DUTY CONNECTOR Screw ¼” x 3″ DB Coating | |
| Unit Cost | $0.16 each | $0.27 each | $0.16 each | $0.15 each | $0.82 each |
| Case Cost | $10.49 per lb | $13.49 (50 pkg) | $16.35 (100-Pkg) | $15.38 (100-Pkg) | $20.40 (25 pkg) |
Strongest Deck Joist Hanger Fasteners
There are two ways to compare fastener strength, withdrawal, and shear. Both are important for the strength of the fasteners but are not equal in value.
Withdrawal strength, the resistance of the fastener from being pulled out. How much effort does it take to pull the fastener out? This is a screw’s greatest strength compare to nails.
Pulling out a smooth nail compared to a screw of equal length is no comparison. A smooth nail pulls out so much easier. As the nail without threads to grip the wood can easily slide out of the wood.
So little force is required to pull a nail out that the expansion and contraction of wood can slowly pull a nail out of decking. This is why you should never use nails but screws to fasten decking to the joist. Screws are superior in their withdrawal strength.
But for hanger fasteners, the greatest concern is not withdrawal strength but shear. The hangers are fastening perpendicular to the joists. With the load pulling against the shaft of the fastener. Failure is a result of breaking the shaft not being pulled out of the ledger. And this is where nails again are superior to screws.
| SMOOTH-SHANK CONNECTOR Nail 1-1/2 x 0.148” HDG | USPStructural Wood Screw #9 x1 3/8” | Simpson SD CONNECTOR Screw #9 x 1-1/2” | Simpson SD CONNECTOR Screw #10 x 1-1/2” | Simpson SDS HEAVY-DUTY CONNECTOR Screw 1/4 x 1-1/2″ | |
| Shank Diameter | 0.148″ | 0.25” | 0.131” | 0.161” | 0.25″ |
| Shear Load | 184 lbs | 181 lbs | 112 lbs | 138 lbs | 180 lbs |
These numbers are thanks to these Mitek and Simpson
Nails, because the alloy of nails is stronger, they have superior tensile strength to screws.
“The properties important to resisting shear are the strength of the alloy from which the fastener is made, its diameter, and the strength of the connection between the fastener shank and its head.”
International Association of Certified Home Inspectors
Nails are just superior to screws for shear strength. The closes screw compared to #10 nail is screws with a ¼” (6mm) shank. Almost twice the thickness for equal shear strength. All meet the requirements for shear fastener strength, but nails do it with less material.
Decks are designed to support 50 lbs per square foot, which means a deck with 2×10 joists at 16″ o.c. at their maximum length is only required to support 533 lbs. A standard 2×10 hanger requires eight fasteners. Using #9 screws will still support the joist sufficiently with 350 extra lbs to spare.
Both screws and nails will support the deck, but #10 nails will do even better.
Joist Hanger Fastener Shear Failures!
A common mistake with fastening joist hangers is using the wrong type of nails. A 2 ½” (64mm) common nail should be just as strong as a hanger nail or even a 1 ½” (38mm) roofing nail. Right? Especially a roofing nail, it’s roughly the same thickness as a hanger nail. Fits the hole beautifully. And if you do some research, have roughly the same nail shear strength as a #9 hanger nail. Why not roofing nails to install hangers?
The nailhead!
The head of the nail is too thin and will break off. A similar fate for most non-hanger nails installed in hangers. It’s not just the shear strength of the nail but also the head connection. Hanger nails are designed with a stronger head to shank connection than other nails. They are not the same. Connection matters, and with deck hangers, it matters a lot.
Another common mistake with hanger fasteners is using the power of #8 deck screws designed for the decking. You already have a case. Just screw the hangers up with them. So the logic goes.
Wrong! Deck screws are too brittle and will break.
The same as roofing nails, deck screws heads do not have sufficient strength for hangers. Tighten up a screw against the metal hanger. You can torque the head right off. Or worse, crack it below the surface, for it looks like it’s holding, but it’s just resting in the hole.
A #8 deck screw is only rated for 89 lbs in spruce. A fraction of the strength of a screw or nail design for deck hangers. But the single most significant reason is the head. The head will break off, allowing the hanger to slip right off the joist, supporting nothing.
Screws are Better for Angle Joist Hanger Fasteners
For double shear fastening, withdrawal strength matters. Screws make quick work of connecting the joist to the ledger. The additional withdrawal strength compounded with their shear strength. Makes an unbeatable combination.
Making the best deck joist hanger connection for strength is #10 1-1/2 x 0.148″ Hot Dip Galvanized nails for the hanger face connection to the ledger or beam and SD CONNECTOR Screw #10 x 2-1/2″ for the angle connections.
Easiest Deck Joist Hanger Fasteners to Install
This is the single biggest reason to use screws. With an impact driver in hand, screws drive in so much easier than nails, especially in tight spaces.
That little 1 ½” (38mm) nails barely sticking past your fingers. One wrong move and your hammering the wrong nail, your fingernail! You set them lightly, as not to crush your fingers and then they fall to the ground before you can drive them in. Yes, screws are so much easier to install in joist hangers.
| SMOOTH-SHANK CONNECTOR Nail 1-1/2 x 0.148” HDG | USPStructural Wood Screw #9 x1 3/8” | SD CONNECTOR Screw #9 x 1-1/2” | SD CONNECTOR Screw #10 x 1-1/2” | SDS HEAVY-DUTY CONNECTOR Screw 1/4 x 1-1/2″ | |
| Installation | Hammer | T20 Torx Drive | 1/4 inch hex-driver | 1/4 inch hex-driver | 3/8 inch hex-driver |
The Simpson Connectors with their 3/8″ hex drive are the easiest to install. The driver’s tight fit holding the screw head preciously in place, allowing movement without dropping out of the drive.
For the angle fasteners connecting the joist to the ledger, screws are even better, both in ease of installation and for their superior withdrawal strength
Best Corrosion Treatment of Deck Joist Hanger Fasteners
Corrosion equals life expectancy with fasteners. Decks experiencing the best and the worst of our environment, from sunshine to blizzards and everything in between, are prone to corrode. The joist fasteners must survive all these destructive elements and more. In particular, the treatment of ACQ lumber. All deck joists must be treated to survive, but the treatment is corrosive to metal. So, what is making the joist last longer is destroying the fasteners.
| SMOOTH-SHANK CONNECTOR Nail 1-1/2 x 0.148” HDG | USPStructural Wood Screw #9 x1 3/8” | SD CONNECTOR Screw #9 x 1-1/2” | SD CONNECTOR Screw #10 x 1-1/2” | SDS HEAVY-DUTY CONNECTOR Screw 1/4 x 1-1/2″ | |
| Corrosion Treatment | Hot-dip galvanized, Class D | Gold Coat Polymer finish | Mechanically galvanized, Class 55 | Mechanically galvanized, Class 55 | Double Barrier galvanize treatment |
https://www.strongtie.com/solutions/corrosion
There is three standard fastener treatment for ACQ lumber and exterior use. Two are galvanized base, what all the Simpson connectors have in common. The other option is what the USP structural screws are treated with, and most deck screws, polymer finish.
Galvanizing fastener is a process of coating with sacrificial zinc which has ten times the resistance to corrosion as steel. There are two common ways of doing this.
“Hot-dip galvanizing is the process of immersing iron or steel in a bath of molten zinc to produce a corrosion resistant, multi-layered coating of zinc-iron alloy and zinc metal. While the steel is immersed in the zinc, a metallurgical reaction occurs between the iron in the steel and the molten zinc.”
© 2020 American Galvanizers Association
A process used since 1742 to protect steel against corrosion. Simple but effective. The easiest way to see if the fastener is hot-dipped galvanized is to look at the shank. If it has a dull grey colour to it, with small specks of metal on it, creating a rougher texture. It’s dipped. If it’s smooth and shiny, but it back. It will rust under your deck.
Mechanically galvanized is a process where the metal is spun in a mixture of zinc powder, chemical promoters and glass beads. The process creates a more uniform coating of zinc on the fasteners, which is important with screws not to damage their threads.
Both zinc treatment methods have a medium level corrosion protection according to Strong-Tie
The simplest way to understand Polymer coating of fasteners is that the fastener is painted to protect the metal from rust. It’s a little more complicated than that, but in short, just like your truck is painted to prevent rust, so are the deck screws.
The biggest difference between zinc treatment and polymer is intent. Zinc provides a layer for the rust to eat away before attacking the metal. Slowing down the process, extending the life of the fastener.
Polymer coating is like a coat or fence protecting the metal. Rather than slowing down the process, polymer prevents corrosion by preventing water and copper from contacting the metal.
The real question here is not how the fastener is treated, but how long will they last? Which of these three treatments will protect the metal the longest?
First, all except the polymer treat, are treated to withstand corrosion in a medium corrosive environment, and even the polymer is not faulty in its treatment. I would feel comfortable using all four but the one that will last the longest.
Hanger Nails Hot Dipped to Level D
There are a few reasons I think this.
First, the polymer is only as good as it can seal the metal. Trying to protect by damming water or sealing of the metal is noble, but in the case that some of the polymers scratches off. Either before, during installation or over time. This can be as simple as when they rub together in your pouch. The water or rust can sneak in and corrode the metal. If possible, it will happen. The polymer coating will get scratched, allowing rust to destroy the fastener.
Therefore, it is better to plan for the rust and water than try to stop it. Which even polymer screws do with a thin coating of galvanized under the polymer to protect the metal. If it’s the better way, then why paint with another chemical when zinc is the answer.
Then it’s a question of quantity. Which process adds more zinc? Looking over the nail or screw in your hand and its obvious, dipping does. The hanger nails have more zinc on them, providing the most protection. Followed by the double barrier, which adds more zinc simple mechanical application.
Enough to cause premature failure? No, but enough to give hot-dipped galvanized nails the highest chance of lasting the longest.
Conclusion Deck Joist Hanger Fasteners
Of these three Simpson approved fasteners and structural screws from USP, I would conclude this. All will work to hold your deck joist in place for many years. The biggest question is going to be installation. Which is more convenient to install?
Hammering is easy enough but driving with an impact driver is easier. Making all the screws options more convenient to connect the deck hangers.
The simpler the design, the cheaper it will be. You can not get much simpler than a nail. Making the traditional hot dipped galvanized #10 nail the most economical. But the difference between nails and similar diameter screws is pennies. Leaning back more to convenience in installation, the larger cost factor than the price for the box.
In longevity, again, the simple nail shines. With the highest level of treatment, it will prevent corrosion for the longest period of time. Yes, the others will last but dipping the fastener in zinc and letting the zinc react with metal will increase its protection.
Screws may have better-holding power, but it’s the shear strength of the shank that matters with hanger fasteners is not resistant to withdrawal. Where again, #10 hanger nails have a significant advantage over screws.
The best Connector arrangement for deck joist hangers may be a combination. SMOOTH-SHANK CONNECTOR Nail 1-1/2 x 0.148″ HDG for the hanger face connection with SD CONNECTOR Screw #10 x 2-1/2″ Mech. Galv. for the angle screws. Locking the joist tight to the hanger and ledger, ensuring support for years to come.
