Deck replacement is a complex project that requires a professional installer. Contact a few contractors and discuss your project goals before making any decisions.
A comprehensive inspection will help you decide whether or not repairs are sufficient. If your deck is showing signs of extensive rot or termite damage, it may be more cost-effective to replace the entire structure.
A good rule of thumb is that if the wood members supporting your deck are in danger of failing, it’s time for a new one. Check them for obvious signs of rot, cracks and other damage.
Look for large cracks in the posts and other structural members, especially those at ground level. Then take a screwdriver and poke into the wood at least 1/4-inch deep. If the wood feels soft and spongy, it’s rotting. Inspect joists, boards and railings for rot too. If you see any, replace the affected pieces immediately to prevent further decay and to ensure safety.
Most elevated decks sit on concrete piers, but even those that don’t extend below the surface need to be in sound condition. To test this, use a flashlight and stand under the deck. Make sure the piers haven’t moved or cracked. The deck should also rest firmly on the joists and not sag.
If it does, jack up the deck and install temporary bracing. A sagging deck can quickly become unusable, and a serious safety hazard.
Another important thing to check is the ledger board, which attaches the deck to the house. This is the main cause of catastrophic deck collapses, so it’s critical to inspect it closely. Look for major cracks and rot, as well as missing or loose fasteners. Make sure the ledger is attached to the house with a metal hanger that’s properly seated in the end of each floor joist. The ledger should also be securely fastened to the joists with lag screws or through bolts.
Decks that aren’t secure can lead to dangerous falls and injuries. While a few minor issues like loose planks or railings might be repaired with repairs, problems such as a spongy, wobbly surface or a ledger that’s pulling away from the house require immediate deck replacement to ensure safety.
You may be able to do some minor repairs on your own, but if the safety problems you identify require a lot of work or impact structural integrity, it’s best to hire a professional deck builder and repairman. This way, you can be confident that the repairs are done correctly and will last for years to come.
Inspect the Joists
A deck is only as strong as its subframe, and it’s essential to ensure that the joists are sound. A spongy spot underfoot is a telltale sign that the decking boards are not sitting on the joists properly. This can cause the board to shift, break or give way under pressure from a person walking on it. The joists should also be free from rot and decay, which can weaken them over time.
Wood is a naturally porous material, and it is not uncommon for small cracks to develop as it ages. However, large cracks that are wide or that are located near connections should be inspected by a professional. Cracks may be due to a faulty construction, but they could also signal that the structure is aging.
Inspecting the joists involves checking to see how the joists are connected to each other, and how they are attached to the support posts. Inspectors will look for proper joist hanger use and spacing, as well as to ensure that the joists are resting on ledger strips. Joists should not be cantilevered over posts more than one-quarter of the joist length, or they will be vulnerable to rot.
It is also a good idea to look for signs of mildew or fungus, which are both serious concerns that require immediate attention. Fungus growth is not only unsightly, but it can also be a significant health hazard for people who walk on the deck. Mildew growth can cause a green tint to appear on the surface of the decking, and it is possible that it may start to penetrate the boards.
When a deck is being rebuilt, the footings should be carefully inspected for damage before the new decking goes down. If the footings are damaged, they may be unable to support the weight of the new deck and the structure can collapse. Occasionally, a footing may have to be replaced entirely if it is deteriorating. If the deck is being built over an old foundation, a structural engineer should be consulted before any work begins.
Inspect the Railings
The railings on a deck are critical to the safety of anyone using the structure. Loose railings can cause injury, especially if people lean on them or if children play against them. Rails should always be made of durable material, such as pressure-treated wood. They should also be well secured to the deck boards and rail posts, ensuring that they are not loose or rotted. Cracks around fasteners and between joists are also a concern, as they can weaken the structural elements of a deck and lead to damage or collapse.
Aside from obvious signs of deterioration such as sagging or shifting of the boards, you can tell when it’s time to replace your deck by paying attention to how the structure feels when you walk on it. A deck should feel solid, not spongy, and it shouldn’t creak or shake. You should also look underneath to check that the joists are not warped or showing signs of rotting.
Lastly, it’s important to inspect the railings for damage. You can test the stability of a railing by pushing and tugging on it. Some building codes require railings to be able to support 250 pounds of lateral resistance. You can also run your hand along the balusters (the lateral pieces of the railing) to make sure there isn’t any give.
It’s also a good idea to verify that the height and spacing of the railings match your local regulations. For example, in California, rails should be at least 42 inches high and the distance between balusters cannot exceed four inches.
Finally, you should look for any nails or screws that are left in the joists after removing the decking. This will help ensure that you don’t step on them and get cut during your cleanup process. You can remove them by hand or with a crowbar and be sure to bend the ends of the nails flat so they don’t get stepped on later. If you find any that are stuck in the joists, it’s best to pull them rather than try to back them out because they may not be able to be removed.
Inspect the Decking
Even the best-maintained deck will start showing signs of wear and tear over time. Depending on the extent of the damage, it could be a matter of replacing some boards or the entire deck.
Begin with a walk through your deck. Check for spongy spots where the wood feels soft or has been soaking up water and sun. This could indicate that rot or other structural problems are in progress. If the spongy spots are isolated, repair may be enough. If they are widespread, however, a full replacement is likely needed to restore the deck’s stability and safety.
Look for cracks in the decking as well as any areas where the boards appear to move away from or give way under pressure. While it’s normal for wood to crack over time, if the cracks are located near fasteners or between joists, they could be exploiting weaknesses in the deck structure. This could make the deck unsafe for use and lead to serious structural issues later on if not addressed.
Next, peer under your deck to see if the beams are sagging or showing any other obvious signs of structural damage. Beams that are sagging indicate they are not adequately sized for the weight of your deck, which could compromise the safety and integrity of the entire structure. The ledger board—the long, pressure-treated board that connects your deck to the house—should also be inspected for damage and decay. This is essential for keeping your deck safe, and a compromised ledger board can lead to serious structural problems for your home.
Lastly, check the underside of your deck to ensure the system used to drain water away from the deck is functioning properly. These systems are vital to preventing moisture buildup, which can cause rotting and other structural problems. If the drainage system is clogged or has become overrun with debris, it’s likely time for a deck replacement. By regularly inspecting your deck, you can keep it in good condition for years to come.