September 30, 2019
Written for AIA New Jersey by William J. Martin, R.A., AIA, P.P.
Originally written August 24, 2016, updated September 29, 2019
Residential decks and balconies are popular architectural features for outdoor family fun in the warmer months. An enjoyable backyard deck that isn’t properly constructed or maintained can turn a pleasant day into a tragic one.
Homeowners and other building owners, including condo and apartment dwellers, should check their balcony or deck each year for signs of normal wear and deterioration.
The first thing to keep in mind with a residential deck or balcony is loading. Decks are designed to carry the normal loads of people, furniture, pets etc. Overloading of a deteriorated residential deck can stress the beams and connectors holding the deck structure together. This stress can, under certain circumstances, pull apart deck components. This can occur when large numbers of people jump, dance or otherwise run from one end of a deck to another, and abruptly stop at the rail. An overloaded and deteriorated deck, under those circumstances, can detach from the supporting structure. Use common sense when entertaining on your deck and have the deck components checked by a licensed architect to determine if repairs are required to restore the deck structure.
Decks and balconies are structural parts of your home or building. These structural parts are not protected from the weather in the same manner as the interior structural parts of your home or building. Exposure to the weather can cause corrosion of metal parts such as bolts and connectors. It can also cause wood rot and deterioration of beams and columns. A visual examination of all these components is the first step in determining if they need attention. Deck and balcony steps, down to the ground, are particularly prone to excessive wear and deterioration. The action of people walking up and down the steps can loosen connectors. Waterproofing of wood members and painting of metal parts with a protective coating can protect and extend the safe useful life of your deck or balcony.
Decks and balconies that are professionally designed and properly constructed have proper handrails and guardrails. These rails protect people and pets from falls either on steps or from the platform itself. Railings should be secured through the decking into the beam under-structure of the deck. Securing the railing in this manner allows it to resist lateral horizontal loading when someone leans against it. If you’re handrails and guardrails are not secured through the decking to the structure below, you should consider having them replaced. The replacement should be properly secured.
Columns that support the outer edge of the deck or balcony should also be checked. These columns carry the weight supported by the deck down into the ground. Deterioration of wood or steel columns can be an issue. At ground level these columns are supported on concrete footings. For a properly designed and constructed deck , these footings extend several feet below the ground. The weight of the deck and occupants is transferred into the ground through these footings. Undersized footings can cause the deck to shift unexpectedly even under normal use. The footings can be observed above ground to see if there is any movement of the concrete. Any observable movement should be investigated.
The columns themselves can also deteriorate from being exposed to normal weather conditions. Waterproofing or painting will help protect supporting members from the effects of the weather. Any observable deterioration should be further investigated for repair or replacement.
Observing the deck from below allows you to see the condition of any metal connectors, bolts, nails, screws that secure deck beams and columns together. Excessive rust, tearing of wood or metal, and nail heads popping out can all be indications of weakening deck connectors. Any of these conditions that are observed should be repaired or replaced.
Just as the columns are important to support the outer edge of the deck, the deck connection into the main structure is important to support the inner edge of the deck at the building. Most decks are secured by bolting a horizontal ledger into the house or building. The bolts used to make this connection can weaken over time while exposed to the weather. This can allow a deck to suddenly pull away from the supporting building causing damage, injury or death. Decks need to secure, not just the horizontal ledger, but also the deck joists themselves. Deck joists on the outside should be connected through the ledger directly to floor joists on the inside of the house. This creates a very secure connection to prevent the deck from pulling away from its supporting building. Deck owners should be aware that metal deck hangers commonly known as joist hangers are insufficient to connect the deck securely into the house. Direct connection between interior structure and exterior structure is necessary for deck safety.
Any visible deterioration of the deck connecting ledger or the nails bolts and screws should be investigated, reinforced, and repaired.
Every year in New Jersey, some 15 or so decks collapse from overloading, improper construction, or weather based deterioration. Being aware of, and addressing the maintenance needs of your deck or balcony is an important aspect of deck safety. These weather exposed structures require significant maintenance. Observe the maintenance needs of your deck or balcony and make repairs immediately when needed. This will help ensure a safe enjoyable deck and balcony experience for years to come.
And, of course, your local, licensed, AIA architect can help you achieve a safe and well designed deck to enjoy for many outdoor occasions to come.
By Stacey Ruhle Kliesch, AIA, AIA NJ Advocacy Consultant | Posted in AIA-NJ News, Uncategorized | Tagged: #AIA, #DeckCollapse, #DeckDanger, #NJ.com, #TimHawk, #WilliamMartinAIA, #wjmartinAIA, Architect | Comments (0)
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