How to Choose the Right Fastener for Your Deck (2023)

Choosing the right fasteners for your deck can feel like an overwhelming decision. Screws, nails, and anchoring hardware have to stand up to many years of moisture, so it's important to select a durable fastening system when building a DIY deck. Standard galvanized fasteners, for example, have a single protective coating, which might flake off and rust. Double-dipped galvanized fasteners are better protected, but you'll get the best life from coated fasteners made for decks. Stainless steel is costly but one of the best deck fastener materials available. We'll walk you through all of the deck fastener options, plus provide pros and cons for each material.

How to Choose the Right Fastener for Your Deck (1)

1. Nails and Screws

Nails are sized by their length, designated by a penny, or d, size. Gauge, or diameter, increases as the penny size increases; a 16d nail is both longer and fatter than an 8d.

  • Common nails, used for general framing, have large heads and thick shanks. They hold well but are hard to drive and may split the wood.
  • Box nails, thinner than common nails of the same size, reduce splitting in 3/4-inch or thinner stock.
  • Ringshank and spiral nails grip the wood fibers and don't easily work their way out. They are very difficult to remove.
  • Finishing nails have slender shanks and small, barrel-shaped heads. Use them for trim work and countersink the heads.
  • Casing nails are heftier versions of finishing nails and provide more holding power.

Screws come in a wide array of styles. A good all-around choice is #10 decking screws—generally in 2 1/2- to 3 1/2-inch lengths. Decking screws are sharp, tapered, self-sinking, and coated for corrosion resistance. With a cordless drill/driver, you can drive them about as fast as nails. Be sure to match your screwdriver bit to the screw head (or vice versa). Decking screws generally are machined with a Phillips, square, or combination head. Square heads drive more securely.

(Video) How to Choose the Right Fastener for Your Deck | HBK Constructions

How to Choose Between Nails and Screws for Deck Fasteners

Screws are nearly as quick to drive as nails and have greater holding power. As long as you drive them accurately, without stripping the head, screws are easier to remove than nails. However, many people don't like the way screw heads look because a small amount of water will puddle inside them. Water will not puddle on a nailhead unless you drive it too deep. To an experienced builder, driving nails is a bit faster than driving screws.

However, if you miss a nailhead with the hammer, or if you drive the nail too far, you will mar the wood. And it is difficult to remove a nailed board without damaging the board.

How to Choose the Right Fastener for Your Deck (2)

(Video) How to Choose a Fastener for Your Connector

2. Framing Hardware

Framing connectors strengthen the joints between framing members. Not too long ago, framing members were joined with nails or screws, but most current building codes now require framing hardware.

Attach joists to the side of a ledger or beam using joist hangers. At the corner, either cut a joist hanger in half using tin snips or use an angle bracket. Angled joist hangers accommodate joists that attach at a 45-degree angle.

Where a beam sits on top of a post, a post cap provides a reliable joint. If joists sit on top of a beam, many local codes allow you simply to angle-drive screws to secure the joists to the beam. Other local building departments require special seismic (or hurricane) ties, which add lateral strength.

A post anchor secures a post to a concrete pier and supports it so the bottom can dry between rainfalls. Get the style that you can adjust so you can fine-tune the posts and keep them on the same line.

(Video) The RIGHT fasteners for your Joist Hangers // The Ultimate Deck Shop

How to Choose the Right Fastener for Your Deck (3)

3. Heavy-Duty Screws and Bolts

To fasten a large piece like a post, use either a lag screw or a carriage bolt. Bolts are stronger and can be tightened in future years if the lumber shrinks. Always use washers under the head of a lag screw or the nut on a carriage bolt so that the fastener does not sink into the wood.

Attach a ledger to brick, block, or concrete with lag screws and masonry anchors. Hold a ledger temporarily with masonry screws, which are not quite as strong but are easier to drive and don't require anchors.

How to Choose the Right Fastener for Your Deck (4)

(Video) Different Types Of Fasteners || Dr Decks

4. Other Types of Deck Fasteners

You can avoid visible nails and screws completely with invisible deck fastening systems. Invisible fasteners come in many forms. They are more expensive and more time-consuming to install, but they leave a clean, uncluttered deck surface. They are especially useful in contemporary deck designs or with complicated decking patterns because they don't distract from the pattern of the decking itself. Deck clips are the easiest to install because you can work from the top of the deck. Continuous fasteners require driving screws from underneath and are better suited to raised decks.

You can also use masonry fasteners. With this hardware, an anchor bolt comes preassembled so its sleeve expands against the sides of a predrilled hole as you tighten the bolt. Drill a hole of the same diameter and at least 1/2 inch longer. Blow out the dust and drive the bolt with the nut just at the top of the threads. Make sure the bolt doesn't turn when tightening. Plastic or soft-metal expansion shields are designed to spread their sides as you tighten the fastener. Drill a hole of the same diameter and length of the shield, and tighten the screw.

Power Fasteners

Power fasteners, such as nail guns, screw guns, and power-actuated fasteners, speed up carpentry projects. Some are powered by compressed air, others use a power cell or chemical or explosive charges. Power fasteners are expensive, but you can rent the tool you need at most rental stores. Plus, they offer many advantages over a traditional hammer and nails:

  • The gun can be operated with one hand, leaving the other hand free to steady the work and keep it aligned.
  • A single blow drives the nail from the gun, eliminating the repeated hammer blows that can jolt a piece out of alignment.
  • The risk of bending a nail or missing the nailhead and denting the deck is eliminated.
  • Nails used in nail guns are thin and have blunt tips that seldom split the wood piece.
  • You can nail in places or positions that would be difficult to reach with a hammer.
  • Many guns can be set to countersink the fasteners or leave them flush with the surface.

How to Choose the Right Fastener for Your Deck (5)

(Video) Decks & Docks - Your Guide to Fasteners

How to Choose the Right Size Fastener

Use these tips to get the sizing right for your deck fasteners:

  • Decking: Fasten 5/4 decking with 2 1/2-inch coated screws or 12d ringshank or spiral nails.
  • Railings: Attach 1x trim, rails, and cap rails with 10d, 8d, and 6d galvanized, finishing, or casing nails.
  • Framing: Use 10d or 16d common, spiral, or ringshank nails (or decking screws) in 2x stock; 8d or 10d box or ringshank nails (or shorter deck screws) in thinner stock. Attach framing hardware with the fasteners supplied by the manufacturer, 16d nails, or 3-inch deck screws. Check with your building inspector—some codes prohibit attaching framing connectors with screws.


What fasteners to use on deck? ›

A good all-around choice is #10 decking screws—generally in 2 1/2- to 3 1/2-inch lengths. Decking screws are sharp, tapered, self-sinking, and coated for corrosion resistance. With a cordless drill/driver, you can drive them about as fast as nails.

How many deck fasteners do I need? ›

The general rule of thumb for standard deck fasteners is 350 screws for every 100 square feet of decking, which is based on standard 6" wide boards (5-1/2" actual), and 16" joist spacing.

How many Trex fasteners do I need? ›

Use three Trex recommended composite decking screws every 12". ALWAYS refer to manufacturer instructions to ensure that recommended screws can be used for fascia applications.

Why is it important to select appropriate fasteners? ›

Picking the wrong fastener can severely impact the quality of your product or service and perhaps even cause your product to fail prematurely or cause you to be unable to fulfill delivery of your product.

What information is most important when determining what fastener to use? ›

In addition to the own weight of the system to be fastened and the loads to be applied, the base material is one of the most important factors in determining the suitable fastener.

How do I choose deck screws? ›

A 3” length deck screws are preferable to 2.5” as they hold better. What is this? A #8 diameter deck screw is ideal, as any higher would split the wood. Remember, if you are using cedar, then you should opt to use a hidden fastening system as these coated screws will stain your cedar.

What type of fasteners should be used with treated wood? ›

Fasteners for preservative-treated wood shall be of hot dipped zinc-coated galvanized steel, stainless steel, silicon bronze or copper.

What are the best fasteners for pressure treated wood? ›

Galvanized, ceramic coated, or stainless steel screws are the best corrosion-resistant fasteners for pressure-treated cedar or redwood.

How many fasteners do you need for a deck ledger? ›

Approved Fasteners

The International Residential Code lists two fasteners for directly attaching ledgers to a house: 1/2-inch-diameter hot-dip-galvanized hex-head machine bolts and 1/2-inch-diameter hot-dip-galvanized lag screws. Note that “carriage,” or “cap head,” bolts are not listed.

How many screws do I need for 5 4 deck boards? ›

So, how many screws should you put per deck board? Each deck board should be fastened with two screws at each point where the board crosses a joist to ensure the stability and durability of your deck's surface. Boards should be fastened to rim joists with three screws.

How far apart should Trex fasteners be? ›

The minimum required width-to-width gapping is 6 mm. When installing in temperatures below 4.5°C, Trex recommends 10 mm gapping. For docks and heavily wooded areas, Trex recommends a 10 mm gap as well. No gapping should ever exceed 13 mm.

How far in do Trex screw holes need to be? ›

Use a 1/8” wood drill bit in the drill and drill a hole at 1” in from the edge of the deck board. The fasteners must be less that 16” on center.

How far apart should screws be in composite decking? ›

Make sure you level both joists to the same height and fasten with 4 screws every 12" to support the composite butt joints.

What are the qualities of good fasteners? ›

What Makes a Good Fastener?
  • Finish options.
  • Agility. A good fastener must be easily and quickly installed. ...
  • Installation options. ...
  • Multiple thread options. ...
  • Holding power. ...
  • Backed by a brand you trust.
22 Sept 2016

What is used to identify strength or quality of fasteners? ›

Inch fasteners—those commonly used in North America—will have a grade or ASTM rating. Property class (often just "class") specifies metric fasteners. Special markings on screw heads and nuts identify the fastener's grade.

What form of fasteners is the most commonly used? ›

Bolts are the most common type of fasteners. These machine elements are usually used to hold two unthreaded components together. A bolt has external male threads on one end and a hexagonal head on the other. The bolt is normally fastened with a nut on the other end.

What is the most common type of fasteners used on wood? ›

Wood screws – These are the most common wood fastener types and are specifically designed to attach wooden boards and planks. Sheet metal screws – These have sharper threads for more easily connecting metal to wood, plastic or other pieces of metal.

What type fastener is used when the most strength is needed? ›

Rivets form a stronger and tighter joint than screws of the same diameter. As a result, they are ideal in applications that require strong mechanical joints like aircraft construction, aluminum watercraft, and military equipment.

What is the strongest type of fastener? ›

BUMAX® Ultra – the world's strongest bolt

Since its launch in 2014, the BUMAX® Ultra range has proven that it is capable of exceeding tensile strengths of between 1 500 to 1 700 MPa on various applications, with good corrosion resistance and an operating range of between -50 and 400°C.

What are the different types of deck screws? ›

Typical drive types include Phillips, Square, Slotted, Torx/Star, or Hex/Allen Drives. The more engaged your drive type, the less prone your screw is to stripping or slipping off the bit when being installed.

Should you use screws or nails on deck joist? ›

Screws are superior for laying down the decking. They hold things flush better and have a better fastener/tensile strength, which keeps boards from popping up over time. However, unless you use more expensive structural screws you need to use nails for structural elements and joists.

What are 4 types of wood fasteners? ›

Fastener Categories

Screws with a smooth shank and tapered point for use in wood. Screws with threads for use with a nut or tapped hole. Machine screws with a thread cutting (self tapping) point. Fully threaded screws with a point for use in sheet metal.

What type of screws and nails must be used in pressure treated lumber? ›

The manufacturers of ACQ, CA, ACZA and CCA and the treated wood industry are all recommending hot-dipped galvanized nails and stainless steel nails and screws with their treated wood products.

Will pressure treated wood eat nails? ›

Simply put, ACQ-treated lumber is extremely corrosive to metal fasteners such as nails, screws, deck hangers, etc.

Should I use hidden deck fasteners? ›

Hidden deck fasteners are a nice way to keep the surface of your deck looking clear and unencumbered. But they are not the right fastener for all decks. In fact, using hidden deck fasteners inappropriately is a formula for failure. Some deck projects require the stronger fastening power of face screws.

How many bolts should be in a deck post? ›

Bolts (at least 5 in. long for 4×4 deck posts, 2 bolts per post) Power drill. Long drill bit (same length as the bolts)

How far apart should ledger bolts be? ›

The fasteners must be compatible with pressure-treated lumber to prevent corrosion. Typically, you will need to install your bolts alternating high and low 2" from the top and bottom of the ledger board. As a rule of thumb, bolts can be spaced 16" on center for supporting joist span up to 12' in length.

What is the most acceptable fastener for connecting a deck ledger to a rim joist? ›

Traditionally, lag screws have been the most common method of attaching decks to buildings. To properly attach a deck ledger using 1/2″ lag screws, 5/16″ holes need to be pre-drilled through the ledger and rim joist. After that, a 1/2″ hole should be drilled through the ledger only.

How do you calculate screw depth? ›

Since the width of the thread and circumference of the bolt are known, we can calculate the number of threads. Now we know the pitch of the threads and the number of threads, so we can calculate the threaded depth. As it turns out, this can usually be simplified to Threaded Depth = 1.5 x Diameter.

What does the M mean on screws? ›

The letter 'M' indicates that this bolt uses a metric thread. The number '8' refers to the nominal diameter of the bolt shaft in millimeters. The number 1.0 is the thread pitch of the bolt, which is the distance between threads, in millimeters. And the final figure, 20, is the length in millimeters.

Is 4x4 enough support for deck? ›

In the past, many decks were built with 4x4 support posts (also called structural posts). But these can bow seriously, even if a deck is only 3 feet off the ground. For that reason, we strongly recommend that you use 6x6s instead, even if your building department does not demand them.

Do I need to pre drill deck screws? ›

In the past, no matter what type of deck board you were installing, the answer to this question would indefinitely be yes. However, with advancements in fastener technology, pre-drilling in most composite and capstock deck boards is no longer necessary.

How far apart should joists be for 5 4 deck boards? ›

Decking Board Considerations

Decking boards span from joist to joist. If you use 5/4 decking, joists must be no farther apart than 16 inches. Decking with boards with a 2x4 or 2x6 span can be 24 inches. If you run decking at an angle, you might need to put the joists closer together.

What fasteners to use with Trex? ›

Trex recommends the use of two screws per joist.

Use recommended stainless steel screws in any areas near bodies of saltwater. 2-3/4" or 3" screws can be used with Trex 2x6 product. Muro T-Screw M-TX0300SEP listed above is approved for 2x6 decking (can also be used with standard 1" (decking as listed above).

Do cut ends of Trex need to be sealed? ›

You won't ever need to seal or stain the deck, and you certainly don't have to (and shouldn't) paint it. And since Trex is a composite material, you don't have to carry out long-term maintenance such as replacing rotted deck boards.

How many fasteners do you need for Trex decking? ›

Trex recommends the use of two screws per joist. All recommended screws are designed to be installed flush with decking surface.

Do Trex hidden fasteners go on every joist? ›

NOTE: When using hidden fasteners (both start and connector clips), one must be used on every joist. ° # of joists x # of decking boards = # of connector clips needed.

Do you pre drill Trex? ›

ONLY pre-drill through the TREX itself. The screw won't seat in the board properly. Instead of sitting down flush with the board, it will stop at the top of the board and just spin.

How many screws should you put in decking? ›

The general rule of thumb for standard deck fasteners is 350 screws for every 100 square feet of decking, which is based on standard 6" wide boards (5-1/2" actual), and 16" joist spacing.

How long should screws be for 5 4 decking? ›

Working with 5/4 board (i.e. 1.25-inch thick lumber), means you'll end up with a planed and finished thickness of about 1.063 inches. This means you'll want to secure these pieces with a 4-inch screw if going into 6-inch joists.

How many screws do I need for a 2x6 deck? ›

Each board should recieve 2 screws per joist, spaced about an inch from each edge.

What is the rule for determining fastener length? ›

Length is measured from the point at which the head sits flat with the surface, to the tip of the threads. Hex, pan, truss, button, socket cap, and round head screws are measured from right under the head to the end of the threads. Flat head screws are measured from the top of the head to the tip of the threads.

What are the 3 classifications of fasteners? ›

There are three main types of threaded fastener; Bolts, Screws and Studs. Bolts have a head on one end (this is usually a hex head) and are threaded on the other.

What are fastener standards? ›

ASTM's fastener standards are instrumental in specifying, testing, and evaluating the material, dimensional, mechanical, and metallurgical properties of the various forms of hardware fasteners.

What is the maximum distance between fasteners? ›

The maximum spacing for bolts between painted members or unpainted members not subject to corrosion is 24 times the thickness of the thinner part (but not more than 12 in.).

How do you measure accurate length? ›

The measure should be carefully positioned so as to ensure that the first mark on the measure (i.e. the mark representing zero) is aligned with one end of the length being measured. You are then looking for the mark on the measure that most closely aligns with the other end of the length being measured.

How long should wood screws be? ›

The total length of the screw should be in the range of 214". When fastening two pieces of 34"- thick stock together, I use 114"-long screws. This gives you maximum holding power without any chance of poking through the lower surface.

What are the strongest fasteners? ›

BUMAX® Ultra – the world's strongest bolt

Since its launch in 2014, the BUMAX® Ultra range has proven that it is capable of exceeding tensile strengths of between 1 500 to 1 700 MPa on various applications, with good corrosion resistance and an operating range of between -50 and 400°C.

What are Grade 5 fasteners? ›

Grade 5. Manufactured from medium carbon steel and hardened for greater strength and durability, a grade 5 bolt is distinguished by 3 radial lines and promises tensile strengths between 105,000 and 120,000 psi. They are most commonly found in automotive applications or those that require medium strength.

What is a Class 4 fastener? ›

Class 4 fasteners are needed in areas with discernible levels of airborne pollution or coastal areas with moderate to high salt levels. They should be able to withstand 2000 hours of salt spray/fog testing, without showing more than 5% red rust on the surface of the fastener head.

What is difference between fasteners and screws? ›

Fastener is a general term to describe something which is used as a restraint for holding things together or attaching to other things. The main physical distinction between screws and bolts is that screws are entirely full of threads while bolts contain shanks without threads.

What fasteners to use with steel? ›

The most common fasteners in use are the hex head Grades 2, 5, and 8. Grade 2 is standard hardware-grade steel. This is the most common grade of steel fastener, and is the least expensive.

What are the characteristics of fasteners? ›

A fastener is a hardware device that mechanically holds objects together. It's used to create non-permanent joints that can be removed or dismantled without damaging the joining components.
Fasteners are typically made of:
  • carbon steel,
  • alloy steel,
  • stainless steel,
  • inconel stainless steel,
  • titanium,
  • aluminium.

What are the 4 main types of threads used on fasteners? ›

Metric, UNC, UNF and More: Thread Types for Fasteners
  • Metric Thread. Metric thread is the most widely used today, and can otherwise be referred to as 'ISO Metric' or 'M'. ...
  • UNC. UNC stands for 'Unified Coarse' and is the most commonly used thread type in the United States of America. ...
  • UNF. ...
  • BA. ...
  • BSF.
21 Aug 2019


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