Here it really depends on the damage of the floors to see if they can be repaired or have to be replaced. Glued down floors are often difficult to remove or will endure a lot of breakage, so we really need to first assess the site to recommend the best solution.
In some cases we were able to remove the flooring and fix the concrete or sub-floor and re-install the existing flooring with minor replacements, but certainly sanding and re-finishing will be required in order to have a professional look and feel.
In case of heavy damage such as rot or termites it might be best to remove the whole flooring, treat the concrete or sub-floor to protect against termites or moisture same as when we do new installations and than install new flooring.
If the damage is only on the surface, such as scratches or cracks and splitting we can use our BONA Mix & Fill after sanding down to the raw timber and than re-sand to a smooth surface and apply the choice of finishing.