4 Important Deck Safety Checks

We get a lot of calls every year from people wanting to know if their existing decks are still safe to use. Whether you are getting ready to sell your house, looking at buying a house, or just want to know if it is safe to continue to use your deck until your budget allows for an upgrade. It is crucial to know when a deck can no longer safely support your family members. There are 4 common problems that lead to decks becoming unsafe, which we will address below. However, these are not the only issues that can render a deck unsafe. Check these 4 points, but if there are any red flags at all, please contact a professional in your area for their expert opinion.

  1. The deck ledger to house connection. The deck ledger is the framing member that is flat against the wall of your house. It is generally attached to the house with lag or through bolts. If it is only attached with nails, you will want to add some lag bolts or ledger screws. This connection should also be flashed with rubber or metal flashing. It can be tough to tell if it is flashed, you may have to remove the back floor board and some siding to see for sure. If there is no flashing, make sure to check the wood for moisture & softness. If you can poke a screwdriver into the wood easily, that may mean that you will need to replace it. An easy way to tell if the wood is rotting down lower between the ledger & house wall, is to add some ledger screws or lag bolts to the ledger board. If the bolts/screws grab well in the house wall, that means the wood is still good. If the bolts/screws just spin out, it may mean that there is rot in the house wall.

  2. The joist to ledger connection. The floor joists are the framing members that run perpendicular to the ledger and usually are supported in the front by a beam & posts. The joists should be connected to the ledger with metal brackets that are U shaped, these brackets are called joist hangers. If these joist hangers are missing or rusted, you will want to add or replace them. They are available at any lumber yard, Lowes or Home Depot.

  3. Heaved or sunken footers. If your deck is heaved up or sinking in the front by the posts & beams, this can cause serious issues. It can cause the deck to disconnect from the house, especially if the ledger connection is weak. If you catch the heaving or sinking early enough, it can be as simple as replacing the footers under your deck posts. If you deck is high enough to work underneath at least.

  4. Inadequate Railings. Several factors can cause your railings to become inadequate. Test the strength of your railings by grabbing the top railing, and pulling towards you. If you can move the railing more than a few inches, you may need to repair or replace them. Use a screwdriver to push in on the wood at the ends of the railing components to check for rot. If the wood is soft, you will need to replace them. If the wood seems to be good, then the issue is generally inadequate fasteners in the posts. You can add some ledger screws or lag bolts to the railing post & framing connections to shore up the railing strength.