Every so often, I write a newsletter on a subject I think might be of interest to both real estate professionals and their clients. You can find links to them below.
A Few Words About Decks
In the USA today, there are about 45 million decks in use residentially. Every year decks or deck railings fail, causing injury and occasionally death to the people using them. Knowing some deck basics may help you be aware of potential safety issues that need to be corrected before someone gets hurt.
Around 90% of deck collapses occur because the deck pulled away from the building before tipping over. A ledger is the beam or board that connects a deck to the house and carries the weight on that side of the deck. It is usually a pressure-treated 2x8 or 2x10 board. Getting a safe and solid connection is key here. Generally speaking, this requires the ledger to be lag-screwed or lag-bolted directly to the house framing with no spacers other than flat sheathing. Fasteners should be a minimum of 3/8 inches in diameter and use washers between the head and the wood of the ledger.
How many fasteners are required depends on the size of the deck. The following equation is a good rule of thumb: On-center spacing of fasteners (in inches)=100÷joist length (in feet). For example, a 12 foot long joist should have ledger fasteners spaced no more than 8.33 inches apart (100÷12=8.33). For maximum holding power, fasteners should be placed no less than 2 inches from the top or bottom of the ledger, and no closer than 5 inches to either end.
Joist hangers are another important safety feature on any deck. They ensure that the joists have a strong and stable connection to the supporting ledger or girder, and help prevent a catastrophic failure of the deck. Toe-nailing with framing nails through the joist end is a notoriously unreliable connection. Any deck built in this manner should have properly sized joist hangers installed. This is usually an easy fix, and could potentially save lives.
Only special joist hanger nails should be used to nail off hangers. These are specifically engineered to have the required shear strength and holding power for the purpose. Undersized, rusty, or corroded nails in joist hangers are concerns that should be addressed without delay.
Railings and Child Safety
One of the most common concerns found with decks is with their railings and balusters. Any deck over 30 inches should have a railing at least 32 in. (residential) or 42 in. (commercial) tall, and supported by well-secured posts every 6 feet or less. Often, the lack of barriers that would prevent small children from falling through openings is found as a defect. To be child-safe, balusters should be spaced no wider than 4 3/8 inches apart. Additionally, the triangular space between the stair treads and railing should not allow a 6 inch diameter sphere to pass through. On open-backed stairs, a 4 in. sphere should not be able to pass through between the treads.
There are many more potential issues with decks. Those listed above are the most important, and the most commonly seen in inspections.