A leaky roof caused water damage to an area of the ceiling approximately 3' x 4'. The ceiling also has a nearby crack that seems to follow a joint, bringing the total affected area to about 5' x 8'. The room itself is 13' x 16':
Is it reasonable to cut out an area of drywall that amounts to about 20% of the total area and patch it with a new sheet of drywall the way one would patch a smaller area? Is there anything that I should do differently for such a large repair? Finally, is this a project that a competent do-it-yourselfer can manage, or should I call a pro?