If you’ve spent a lot of money in the past on your flooring, or perhaps you’ve just moved into the house and are ready to start working on upkeep, and find yourself in the middle of a sagging floor – don’t panic. Rotten wood joists in basement locations aren’t unusual, though it is an awkward hassle and needs to be fixed. The worst part is, in the basement, you can’t always simply get underneath the floor to fix the joists, which are what is causing your flooring to sag and creak.

You can fix the rotten joists yourself, but if a lot of them have rotted and need repair, the job won’t exactly be something you can complete quickly. You may have to remove all the furniture and items on the floor, take out the flooring, and replace all the joists and check for any additional rotting materials. Depending on how quickly you were able to solve the problem, you may need to install an entirely new sub-floor. However, before getting to that stage, here’s a quick look at how to go about fixing the rotten wood joists first.

Replacing Rotten Basement Joists

As inconvenient as it may seem, you will probably have to take up your flooring to replace the joists. However, if only a few of the joists have rotted at the bottom, you may be able to simply sister the joists and be finished with the process.

To sister a joist, lay the new joist next to the old one, and secure it in place by firmly fastening it to the adjacent joist. Depending on whether or not your current flooring is held firmly in place by the old, rotting joists, this process could be enough to fix the problem. On the contrary, it’s really only a temporary solution and not exactly the most professional option for repair work.

If the rotten floor joists are not holding the floor up correctly, you’ll have to endure a longer repair process. Instead, toe-screw or toe-nail your new joist all the way through to the flooring.

You will need to go through the process of determining which screws or nails are long enough to go through the joist and attach to the floor without sticking out through the top of your flooring, while also considering the angle that the nails will have to go in to prevent penetrating the flooring’s top. You might also consider using ‘Deckmaster’ brackets instead, to avoid any potential mishaps.

In Case of a Rotten Sub-Floor

If the wood joists in your basement flooring have rotted to the point of needing to be entirely removed and replaced, it’s also likely that the rest of your sub-floor is going to be needing removal and replacement as well – after all, moisture doesn’t tend to attack one piece at a time, but instead effects entire areas.

In this case, you really will have to remove all your flooring in order to rip up the whole sub-floor and fix all the rotted wood. Be sure to get every piece that shows signs of rot, since the spores from the old ones will be more likely to begin to rot new wood than if they contacted moisture without the spores around.

If there is organic debris under the house from the rot, remove it! If not, you may attract termites and exacerbate the situation, or find yourself replacing the entire sub-floor again in the near future. The crawlspace under the basement floor will also need adequate ventilation installed, as this may have caused joist rot to begin with. Install a powered vent and a plastic vapor barrier, just to be safe.