What to Consider
Determining the design of the deck and the material of which it will be constructed are the two biggest decisions when building a deck. But using the correct hardware in construction is important to the life of the deck and the safety of those using it. Since many decks still in use were created more than 20 years ago and prior to new codes, retrofitting hardware on wood decks is a consideration. Injuries due to collapsing wooden decks are one of the greatest causes of construction-related injuries each year according to the U.S. Consumer Safety Council.Determining the design of the deck and the material of which it will be constructed are the two biggest decisions when building a deck. But using the correct hardware in construction is important to the life of the deck and the safety of those using it. Since many decks still in use were created more than 20 years ago and prior to new codes, retrofitting hardware on wood decks is a consideration. Injuries due to collapsing wooden decks are one of the greatest causes of construction-related injuries each year according to the U.S. Consumer Safety Council.
Building Codes: Because codes vary from area to area due to climate as well as safety, check with the building department for accurate information for purchasing hardware when constructing a deck.
Corrosion: Decks are outside facilities, exposed to the weather and temperature changes, even salt air, and will require hardware that withstands corrosion when exposed to these situations. Decks in dryer, more temperate climates will not require nails and screws to meet these circumstances. Building codes and material manufacturers will recommend the proper fasteners for their deck boards.
Material: Depending upon the material for the deck floor and railing, follow the manufacturer’s directions for fasteners. Treated woods require fasteners manufactured from materials that won’t corrode due to chemicals — copper — used as preservatives in the wood. ACQ treated lumber requires ACQ compatible fasteners. Cedar and Redwood will corrode galvanized fasteners; black marks will result on the wood plank due to chemical reactions of tannins in the wood and the fastener.
Deck Support Structure: Even if Ipé or a composites create the deck surface, treated lumber will be used for the supports. Purchase hardware that is compatible for the deck system.
Continuous Load Path: In areas prone to high winds and hurricanes, decks will be designed with a continuous load path, which means the structure will be interconnected, such as the links of a chain. Uplift winds will be deterred from moving the deck by the joist and beam attachments to the house and the ground.
Ledger Boards are connected to the house or building to support the joists under the deck. Nailing ledger boards does not meet today’s code requirements.
Lag or Carriage Bolts with washer 4” to 6” long will penetrate a 2X ledger board, the home sheathing and structural band joist.
Structural Screws with integral washer head or added washer should be ACQ approved and long enough to penetrate the ledger, structure’s sheathing and rim joist.
Concrete Expansion Bolts are used when the ledger is attached to concrete and not to a wood structure.
Tension Ties attach the joist of the deck to the joist of the home for preventing lateral load lift.
Joist-to-Ledger connectors support the joist at the ledger board. Some may attach to the ledger board around the joist, or behind the joist as an invisible support. Size the hanger to the size of the joist. Angled hangers are available for left or right hand angled decks.
Post Bases will attach to the concrete footings poured into the ground underneath the deck. Post bases can be attached to the finished concrete, or embedded into the concrete at pouring. Use materials compatible to the preservative of the wood posts, or offset the post in the base so it does not touch the metal and corrode it.
Beam-to-Post connectors attach the post support to the beam, providing extra strength for wind resistance. The connectors fasten the top of the post to the beam of the side of the post to parallel beams.
Retrofit Post Caps are available to attach existing posts to beams on older decks that are not code compliant. These are connected along the side of the post to the beam.
Joist-to-Beam hardware provides support to resist lateral or uplift forces, which sometimes are called Hurricane ties. Wood blocking will be required depending upon the span of the beams.
Rail Posts can be attached to the outside of the rim joist, or inside the rim joist. Using Tension Ties provides the strength to meet safety codes.
Stair Stringer and Tread Supports can be installed for ease of construction and extra support on deck stair systems.
Fasteners should be the same material as the connectors to alleviate chemical corrosion between the types of metals. Fasteners may be coated for use with a variety of treated woods, hardwoods, and composites. Stainless steel is more expensive but resists corrosion. Consult the deck plank manufacturer’s instructions when choosing nails and screws. Warranties may be void if the manufacturer’s directions are not followed.
Nails are used on decks to attach framing members, but must be long enough to penetrate fully and provide the necessary support. Codes require hot dipped galvanized or stainless steel nails. Using spiral or ring shank nails reduces popping.
Augur nails can be used on hardwoods to avoid splitting the wood and may alleviate the need for pre-drilling.
Screws are designed in a variety of shapes and sizes to penetrate and lock the material in place. Created in stainless steel or coated dipped galvanized for use in treated lumber, in composites and hardwood, the color of the screw may match the color of the deck plank. Some manufacturers create screws specifically for the different plank materials.
Hidden Fastener Systems are available from several manufacturers. Some require enough space underneath the deck for attaching them to the beams; others are installed from above.
Biscuit types are created in polypropylene, plastic or metal and require a cut into the deck plank to accept the biscuit. This may be a more time consuming method of attaching the deck planks, but provides the proper spacing between planks for expansion and water drainage.
Clip systems are created from a variety of metals and attach to the beam and inserted to the plank with a claw.
Track systems involve a metal strip that is attached to the beam and then to the plank from underneath.
Material: Stainless Steel connectors and fasteners are more expensive. On a large deck, the number of connectors and nails/screws needed will add to the budget when using stainless steel. Powder coated or epoxy coated steel are more expensive than galvanized, but the lumber or plank material may not be compatible with galvanized — cedar and redwood especially. Check with the building codes as well as manufacturer’s warranties.
Installation: Hidden fastener systems are more expensive than top screwing or nailing. The time to install with a hidden fastener system will add to the cost of the deck if using a professional.