Proudly American
Put the test area on paper
A sketch can show whether the provider means an exposed brick face, the roof junction, a crown edge or a combination. Ask which area will remain outside the test. If several surfaces are wetted at once and a mark appears indoors, that observation alone does not distinguish between the surfaces. A test method must match the question the provider is trying to answer.
Ask what the result measures
ASTM C1601 describes a field method for water penetration of masonry wall surfaces. Its scope explicitly distinguishes the surface under examination from overall leakage of a masonry system. If a contractor cites this method, ask whether it will actually be performed and what its result describes. An informal spray from a hose and a measurement to a specified method should not receive the same label.
Interpret a dry visit carefully
Suppose no indoor water appears during the observed test period. That can be reported as a limited observation. It does not erase a documented leak during a different wind or rain event, nor establish that a roof junction outside the tested area is sound. Preserve both the dated indoor observation and the test notes instead of discarding one because the other looks conclusive.
Agree on the next decision before paying for the test
If the surface admits water, what repair choice would that change? If the surface does not, where would the investigation go next? Ask who will protect finishes and stop the test if moisture appears inside. Do not aim a hose at the roof, firebox or chimney yourself to make a symptom appear.