<human>:  I have a sagging roof, what can I do to repair it?
<bot>: One option is to hire a professional roofer to inspect and repair your roof. They will be able to evaluate the condition of your roof and recommend the best course of action to repair it. You may also need to replace shingles, inspect your attic for water damage, and repair or replace flashing. Depending on the age and condition of your roof, it might be best to replace it altogether.