Should I Sister a Floor Joist?

When your floor is sagging, the problem can lie in a failing floor joist. One common recommendation among DIYers is that if the floor joist is damaged, sistering can help. Sistering a floor joist refers to attaching a new, healthy wooden board to the failing one in order to stabilize it. While this may work on some occasions, it can actually be detrimental to your home’s health most of the time. Sistering a joist is like wrapping a leaking pipe in duct tape: it’s a short-term practice that doesn’t actually fix the problem.

Instead of grabbing another piece of wood, ask yourself why the floor joist is failing in the first place. If it’s because of wood rot, then the wood you use for reinforcement will suffer the same fate a few months down the line. Anything that damaged the original joist, be it termites, wood rot, or water, will damage the new one as well. If the problem is that the floor simply wasn’t supported enough, then sistering might be able to help in those instances. However, to make sure you have the right solutions repairing and protecting your house, it’s best to reach out to professionals for help.

We at Innovative Basement Authority can assess the damage to your Bismarck home’s crawl space and let you know exactly why the supports are failing. If it’s a moisture issue, then we have the solutions that will ensure your joists never get waterlogged or infected again. We also have SettleStop IntelliJack™, a crawl space support jack capable of lifting your uneven floor. It’s made of galvanized steel and it’s a lot more reliable material for support than a piece of wood.