Not much beats spending time relaxing on the backyard deck, a good book (or beer) in hand, listening to baseball on the radio, watching the kids play, or hanging out with friends. It’s important, though—regardless of your deck’s materials—that you thoroughly inspect it at the beginning of each deck-using season for wear and tear.
Sometimes, it’s a simple matter of tightening a bolt here and there or sanding down some roughed-up floorboards. But if your deck shows any of these signs, it’s probably time to replace it, especially since experts estimate that deck, balcony, and porch collapses have injured an estimated 6,500 people since 2003.
Evaluate your deck’s health
Railings shake when you grab them. If the railings lean out or wobble when you touch them, that’s a problem—and a safety hazard. Railing posts attached only with nails tend to loosen over time. You can secure them more firmly using galvanized steel carriage bolts with nuts and bolts but depending on the condition of the posts to which the railings are attached, the problem won’t be solved long-term.
The posts are beginning to show signs of rot. Even pressure-treated lumber isn’t immune to rotting, especially when it’s exposed to the elements. If only one or two posts are rotting away, you may be able to replace them and continue using your deck. But chances are, if you can see the rot in one or more posts, the other posts are likely in similar shape—especially if they’re the same age. Posts provide the support and stability for a deck, and if they break without warning, people on the deck can get seriously injured.
Erosion around the bottom of the posts. Newer decks sit on posts that are anchored deep into the ground (48 or more inches is common to get below the frost line), on top of special brackets (to keep water from leaching into the bottom of the post and rotting it) and secured with concrete. Over time, the constant exposure to elements—especially if you live in a climate that includes a decent amount of snow and/or rain each year—can destabilize the deck. You’ll notice it by checking to see how much of the posts are exposed. And if the concrete anchors that hold the posts in the ground begin to show, you’ll definitely want to replace the posts.
Widespread discoloration or stains. Wood decks weather over time, even when they’re built with pressure-treated wood and stained or painted regularly. However, accidental chemical spills (think harsh cleaning liquids) or even the build-up of grease from your grill can corrode the deck’s finish and eat away at the boards over time.
The ledger boards no longer attach your deck securely to your house. Ledger boards are a critical component to a deck’s framework and stability. These boards are the back of the deck that are used to attach it to your home. If the ledger boards are wobbly, warped, or pulling away from the house wall, they’re compromising your deck’s integrity and can lead to its collapse.
The ledger flashing is gone. In addition to the ledger itself, you’ll want to verify that its flashing is also secure. The flashing covers the ledger to prevent water from leaking between it and your house. Without a watertight connection, the ledger board will rot over time. In fact, water damage is a leading factor in deck collapses.
The joists and post connections have weakened and become unstable. Check the understructure to check for solid wood. Test the wood’s softness with a screwdriver. If you can push the screwdriver a quarter inch or more into the wood, it needs replacing. Joists become unstable over time as they’re exposed to harsh weather elements. Since these elements provide the base “skeleton” of your deck, they need to be strong and rot-free to keep the deck from collapsing.
The deck planks wobble when you walk on them. First, remember that some boards will naturally age faster than others and when you inspect them each year, it’s relatively easy to identify which to replace. Use galvanized or stainless-steel screws, not nails, when you do replace boards. If, however, the deck’s entire floor wobbles or feels unstable when you walk across it—or there’s a spongy-like “give” that makes you feel that you could fall through if you jumped up and down—take that as an indicator that your entire deck probably needs replacing.
You see other structural damage that’s past the point of rescue. Even if you can’t see visual rot, a sagging deck indicates its presence. Rotting wood also becomes susceptible to termite damage, which further weakens its stability. When you examine the deck and regularly find more hardware on the ground—or you replace screws that don’t hold the frame or have the same effective purchase—that’s another indicator that it’s time to replace your deck.
Hardware is missing or corroded. Nails, screws, and metal connectors rust over time. Look for signs of corrosion that could possibly weaken your deck’s structure. Screws that have lost their ability to hold joists or framework together indicate that the wood is weakening.
Cracks. Wood cracks naturally as it ages; however, large or excessive numbers of cracks weaken your deck and make it unsafe.
Your deck is older than current regulations. Hire a professional to inspect your deck if it’s more than six years old. Professionals know what to look for, and especially if you live in a place with extreme temperature swings each season, those temperatures can dramatically affect your deck’s structure and stability.
An average treated lumber deck’s life expectancy is 10 to 15 (sometimes 20+) years. The type of wood with which a deck is built can also affect its lifespan.
- Cedar decks can last 25 to 40 years with regular TLC. Because it’s a more high-maintenance wood, you’ll need to clean it often and seal it annually.
- Mahogany and ipe decks resist rot and mold and good options for active, large families with lots of kids and critters. With regular, annual maintenance, they can last up to 40 years.
- Pressure-treated lumber made of better-quality wood (read: more expensive) could last up to 40 or 50 years, but it tends to warp and shrink over time more rapidly than other wood decks.
Composite decking has become another popular material to use over the past 20 years; the industry standard lifespan—with relatively minimal maintenance—is at least 25 years. There are other quirks common to composite decks that you won’t find with a lumber deck.
Regardless of the material from which your deck is built, proper maintenance—which includes annual power washing or cleaning, staining, sealing, and minor self-repairs—is vital to keeping it safe and protecting everyone who uses it.
For more specific information, and a 9-point deck safety consumer checklist, visit Yellawood.