01
Choose boundaries by construction
Ask the designer and slater to identify logical stopping points using the roof geometry and drainage routes. A line drawn to create equal areas may cross a valley, wall connection or concealed flashing that cannot be sensibly divided. Show each proposed boundary on a drawing and identify any work that must cross it to complete the first phase.
02
Describe the interim condition
Require the scope to explain how the roof will perform between phases, including temporary details, inspection and maintenance responsibilities. Record the intended duration and what happens if funding for the next phase is delayed. Avoid an interim arrangement whose limitations are understood only by the installer; the owner may need to manage it through more than one season.
03
Preserve the next phase's access
Review where scaffolding, delivery, storage and protective measures will go when work resumes. Consider whether reaching an unfinished area will require crossing newly completed slate. Store approved matching material with clear lot records if it is being reserved. Do not assume a later shipment will duplicate an earlier appearance without checking availability and acceptable variation.
04
Close each phase as a complete record
Document finished areas, interim junctions and remaining scope separately. Keep photographs before boundary details are concealed and identify any component intended to be replaced later. At the next mobilization, inspect those junctions before extending the work. A phase should end with an understandable owner record, even when the overall roof project remains unfinished.