Is your deck safe?
Greetings from your friendly neighborhood deck builder,
We hope you’re staying safe and warm in the 2024 “Snowpocalypse”! We know with the weather the last thing on your mind is your outdoor living space. But maybe now is a good time to consider safety. Safety for your family and your friends who love your backyard shindigs.
Question:
Is your deck safe? Is deck failure really that big of a deal?
According to InterNACHI, of the two million decks that are built in the United States every year, less than half are safe. And the Consumer Product Safety Commission states that 6,000 people are injured through deck failures in the United States every day. That is common enough that you should be concerned about whether your deck was built safe, and if it will fail. Today’s Blog will take us through Ledger safety. Over the next few weeks, we will hit on the other failures in your deck and ways to prevent these serious safety issues.
The Most Dangerous Failure
LEDGER FAILURE
“The leading cause of deck collapse in North America is ledger board failure.”
These are the top 4 reasons your ledger can fail and preventions for each:
1. Ledger board pulls away from the house: In older construction, and with some well-meaning DIY homeowners the ledger board is often just face nailed to the rim joist.
PREVENTION; More recent codes required lag screws or through bolts when attaching ledger to home. Simpson’s “DTT2Z Deck Tension Ties” are required by most municipalities. This bracket extends into the home, providing a solid connection from the house's floor joists through the rim and ledger boards to the deck joists.
2. Ledger board splits: When a ledger board is attached to a house and fasteners are installed in a straight line, a crack will form along the length of the board and cause it to fail.
PREVENTION; A staggered screw pattern is required by code. One near top and one near bottom between each joist.
3. Improper Flashing: Many ledger boards rot prematurely due to lack of proper flashing. Some rot because aluminum flashing is used against pressure treated wood.
PREVENTION; Ledgers should be flashed with galvanized steel z channel to prevent moisture attacks from above, and butyl barrier materials should be used between your home and the deck ledger.
4. Joist Hangers/Fastening Joist to Ledger: We have demolished many decks where joist were simply toenailed to ledger and had pulled away from house. If you do not use proper rated hardware corrosion sets in and failure happens at the connection point.
PREVENTION; Always check the manufacturers recommendations for exterior use of your hardware and fasteners. Corrosion will occur in hardware not rated for exterior use and your deck can pull away from your ledger.
Next time we will talk about second biggest failure in your deck and more ways to keep you and your family safe.
-FOUNDATIONAL FAILURE
Still to come in our four-part series.
-GUARD RAIL FAILURE
-STAIR FAILURE
See diagram below of the components mentioned above.