Watch Your Step: Deck Safety 101

Roughly 2.5 million decks were built last year; some by contractors, others home owners.

Improperly installed and aged materials create a dangerous situation. I understand that money is tight right now and people want to do their own projects, however, most people aren’t familiar with the specifics on lumber species that are best used for decks, such as cedar joist or treated wood joist materials. These errors could mean the difference between a safe deck and a hazardous one

I’ve seen many instances of deck failure where people were either seriously injured or killed.  Most of the problems come from decks being overloaded by people having parties; especially on holidays and special occasions. Again, with the proper species of wood, correct spacing, and spans, a wooden deck will hold a sizable amount of weight.

According to the American Forest and Paper Association, different wood species have different strengths. So what does this mean? Cedar joists might have a different span and load rating than treated joists. Fiber bending characteristics are different between species and modules of elasticity vary. Also, newer preservatives used on wood can be corrosive when in contact with any metallic materials such as hangers, flashings, nails, etc.

The farther the deck is from grade the more it will wobble. To avoid this problem, place your deck posts on top of concrete footings at least 8” thick. Once the posts are placed, surround them with concrete for additional support. Footings should be below the local frost level (at least 3 feet in this area) and on undisturbed soil and should be at least 12” to 18” in diameter.

Another problem I commonly notice is that nails are the only means of support for deck construction. Nails are weaker than lag bolts or carriage bolts. These bolts can support a greater amount of weight than nails when properly spaced. However, nails are prone to failure under great stress.

When fastening the deck to the building, make sure there is a band joist at least 2” wide attached to the existing structures. This band joist should be attached to your floor joist. I recommend using either ½” to 5/8” wide and at least 3 ½” long lag or carriage bolts and washers with two bolts spaced every other bay on the treated deck header. Be sure to check for plumbing or wiring before installing them.

Simpson Strong-Tie sells a variety of approved deck fasteners. When shopping for fasteners it is important to look for an approved testing agency seal such as, American Society of Testing Materials. It should be visible on most products.

Steel Floor Joists Span 6.9m | ebossNOW + Detailed | Architectural ...

The RFS-Steel Floor Joist system is being used widely in residential, commercial and industrial projects in New Zealand and around the world including Australia, the Islands, Tahiti and the UK.

The revolutionary punched tab system in the bearer makes setting out easy and accurate, meaning floor sheet layout is quicker and reduces cutting on site.  Each raft is detailed accurately and sent to site cut to length kitset style, no cutting or measuring required!

A 290mm deep C Section Joist is used which has 140mm Service Holes punched every 1m.  In a 1.5kPa live load use this will span 5.9m @ 400 centres and does not require any blocking.  4 section depths are available from 140mm.

Free software is available from RFS to allow you to detail the RFS-Floor Joist system, giving you a layout, total quantity and price set by you, straight to your customer.

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Construction codes and inspection handbook

Architectural drafting and design

Black & Decker Codes for Homeowners, Electrical Codes, Mechanical Codes, Plumbing Codes, Building Codes

APA engineered wood handbook