As a Florida licensed real estate broker associate I am not an attorney and can't provide legal advice. Still, the Florida Realtors®/Florida Bar contract I routinely use addresses the issue.
What does the Florida Realtors®/Florida Bar Residential Contract for Purchase and Sale say?
Two phrases stand out - "by an appropriately licensed person, in accordance with all requirements of law" and "shall consist of materials or items of quality, value, capacity and performance comparable to, or better than."
Although I am not a lawyer, I think this is clearly saying hire a professional and don't skimp on repairs. Sellers should be prepared to provide receipts to document payment as well.
Of course this could be a non issue if the "other" contract is used - the "As Is" Residential Contract for Sale and Purchase.
For legal advice regarding real estate transactions consult an attorney.
Considering selling your Viera, Florida home? Call me at 321-693-3850 if I can assist in any way.