To repair a cane chair, you must first determine the specific problem. The most common problems with cane chairs are strands becoming loose or breaking off and sagging of the chair.
First, inspect the chair to establish if any of its strands is loose or broken. Tack back into the frame any loose strands and tack it in place using glue.
Remove any broken strand by pulling it from the frame. Get a new strand and soak it in water for between 30 minutes and an hour. The strand should be soft enough to work with. Measure the strand being replaced, and cut off a section of the new strand slightly longer than the strand being replaced. By following the pattern of the chair, weave the piece into the chair. Then, trim the excess length before gluing the ends into the frame. After glue has dried, paint the repaired areas to correspond the rest of the chair.
Sometimes, the strands may begin to stretch out making the seat to sag. You can fix this turning the chair upside down and moistening the wood using a damp rag. Allow the chair to dry in that position. The wood will shrink back as it dries.