Access is the variable people underestimate
Roof pitch and height determine whether work is straightforward or needs staging or a lift. A steep slate roof and a low single-storey pitch are different propositions for identical work. Inside, whether an insert or appliance has to be disconnected and pulled to reach the connection can add substantially, and it is frequently invisible in a quote that just says the service name. Ask what it includes.
Scope is where two quotes stop being comparable
The heading tells you very little. For a reline, the comparable details are liner material and grade, diameter, whether it is insulated, how it terminates and what happens to the existing tile. For masonry, it is where the work starts, how many courses, and whether crown, cap and flashing are included. Two numbers without those details are not a comparison.
Season and weather windows
Mortar has to cure above freezing, so repointing, crown casting and rebuild work have a genuine season in Vermont. Work scheduled at the edges of that window can involve protection and delay. Sweeping, inspection and appliance service run year round, though the calendar tightens sharply once the weather turns.
Why a quote can legitimately change
A scope built from photographs is a starting point. Once someone is on the roof or has the appliance apart, they may find failed tile behind an offset, spalling that only shows close up, or a connector that has to be replaced. A good contractor tells you what would change the number before starting, and gets your agreement before doing extra work. Insist on it in writing.
Compare the finding, exclusions and warranty
Ask each company to identify the defect and how it was established, then price the same repair. A liner proposal needs diameter, metal grade, rigid or flexible construction, insulation and termination details. For masonry, identify which joints or courses are included and whether the crown, cap and flashing are part of the work.
Put the unanswered quote questions in writing
Check whether tile removal, staging, appliance removal and disposal are included or possible extras. Ask what weather or access conditions could change the schedule or price. Request the warranty duration, coverage and exclusions. A lower total only represents a cheaper offer after both proposals describe the same work.