A workmanship guarantee relates to the agreed work completed by the contractor. A product warranty comes from the manufacturer and follows its own terms. These are separate commitments.
Read the written coverage
The quotation or completion document should specify any guarantee period, the work covered and conditions that apply. A localised repair does not automatically warrant adjoining materials or concealed construction.
Understand existing conditions
Ventilation, maintenance, substrate condition and an unresolved external cause can affect the result of a repair. Where these matter, they should be explained before work begins.
Raise a concern promptly
If a customer believes workmanship is defective, photographs and a clear description help the contractor arrange an inspection. Reasonable access gives the team a chance to establish the cause and respond within the agreed scope.
Details that improve the decision
Ask about the remedy available if a concern is confirmed, and how to report it. Keep the quotation and handover documents because they define the covered work. Damage from a new leak, movement or poor maintenance may call for a fresh investigation even if it occurs near a previous repair.