Small holes under 6 inches and isolated hairline cracks are almost always best repaired with a proper patch. Large sections with water damage, active mold staining, or significant structural impact are better replaced — cut out the damaged board and install new material. For restoration projects with widespread damage across multiple walls, a full re-board and refinish often costs less than attempting panel-by-panel repairs and produces a far more uniform result. RainFire Builders will give you an honest assessment of what makes sense for your specific situation rather than defaulting to the more expensive option.