Identify every opening before choosing a lid
Ask the chimney professional to label the flues on a photo and record the appliance or fireplace connected to each, where known. Treat an opening with no clear history as unidentified. A change meant to keep rain out of one flue must account for operation and service access at the others. These masonry-cap choices do not automatically apply to listed metal vent terminations.
Ask for the dimensions that drove the choice
A photograph taken straight down can hide a difference in flue heights. HY-C’s multi-flue guidance distinguishes the footprint, the available mounting area and clearance above the tallest tile. Have the assessor identify the specific cap and confirm that the measured arrangement fits its instructions. Homeowners can request the labeled photo without going onto the roof to collect measurements.
Discuss the next service visit
Ask whether a professional can reach each flue for inspection and cleaning, what section of the lid must come off and how the cap will be secured again. If the crown beneath the mounting area is deteriorated, have that condition addressed separately in the estimate. A larger screen does not repair the support to which it will be attached.