If the timber around the top rollers in your wooden bifold doors were to become damaged, the doors would actually stop operating as they are supposed to because they cannot remain stable. When it comes to rectifying this damage, you should focus on either the roller or the bifold itself, depending on how extensive the damage is.
Step 1: Lift the bifold up and swing the bottom pin out of the floor bracket. Then, pull the door down and remove the top roller from its track. Set the panel aside and carefully inspect the damage.
Step 2: If the damaged area is quite extensive, you will probably be better off by purchasing a replacement bifold door. Measure the height and the width of the panels whilst they are open using a tape measure.
Step 3: If the damaged area is centralized around the top roller, you can instead choose to repair it. Unscrew and remove the roller and carefully wipe the timber down using a clean, damp rag.
Step 4: Apply some wood glue to the affected area, then place a small wooden shim between each jaw of a spring clamp; use them to clamp the door into place whilst it dries. The shims are to protect the timber.
Step 5: Remove the spring clamps for the bifold once the glue has dried and screw the roller back into place, using a hammer if necessary. If it has sustained extensive damage, however, you might like to replace it.
Step 6: Replace the bifold by locking the top roller back into the track and sliding the bottom pin back into the floor bracket. You might need to push down slightly on the roller so that it clicks back into the track.
As you can see, repairing wooden bifold doors that have sustained any amount of damage around the top rollers is actually quite a simple process, especially if you know what you’re looking for. Whilst it might just seem easier to replace the entire door, keep in mind that rectifying the problem can actually be a much cheaper and quicker option.