Before you approve a rooftop AC replacement, ask the HVAC contractor and the roofer to mark what stays, what comes off and what will be open to the weather. Put a name beside each opening: who protects it during the swap, who makes the permanent seal and who checks it before the crew leaves. Settle those assignments before you book the lift.
Two proposals can both be accurate and still leave a hole in the job. The HVAC quote may cover removing the old unit and starting the new one. The roofing quote may cover flashing one new opening. Neither line tells you who closes the old pipe hole ten feet away.
Start with the base under the unit
The raised frame that supports many rooftop units is called a curb. Flashing is the material that seals the roof covering to that frame. Ask the mechanical contractor to show you the old and new equipment footprints on the same sketch. Is the existing curb staying? Will an adapter sit on it? Or will the crew remove or move the curb? Those are three different conversations for the roofer.
If the plan says “reuse existing curb,” ask which connections will still change. A new unit in the same spot can still need a different route for a line or duct. If equipment weight, support or the size of the opening is changing, ask who will verify that the building can carry the proposed unit. A roof-surface inspection does not answer that question.
Walk through one marked-up photo together
Ask the contractors to label the equipment, pipes, wiring routes and any old openings on one dated photo or drawing. You can do this from the office; ask the crew to supply roof-level views. For each mark, record the existing condition, the planned change and the person responsible for finishing it.
Example: “Line A stays. Line B moves to the west side of the unit. HVAC disconnects the old line; the roofing contractor closes the old opening and flashes the new one. The owner receives a labeled photo of both locations.” That is more useful than a line that just says “seal as needed.”
Ask where the crew will set the removed unit, stage tools and travel between the access point and the work area. Identify any drain or service route that must stay clear. Your roof maintenance plan may already have a drawing and photos to start with.
Decide what happens if the lift stops halfway
Suppose the old unit is off and the replacement arrives with the wrong adapter. Who can authorize a stop? Who is responsible for protecting the opening until work resumes? Ask how the building manager will know the roof is secure before the last contractor leaves, and who answers the phone after hours. Temporary protection and the final roof repair should appear as separate tasks.
Check the actual roof warranty before work starts
Find the roof warranty number and the issuer’s contact information. Send the proposed change and ask whether advance notice, a particular roofing contractor, written approval or a follow-up inspection is required. Keep the reply with the proposal. The new AC equipment warranty is a separate document.
For example, the Elevate roofing owner’s manual gives specific reporting and applicator requirements for changes to roofs under its Red Shield warranty, including changes involving curbs and penetrations. Use the instructions for your own roof and warranty.
What to keep when the new AC starts running
Ask for three things: the marked drawing updated to show what actually changed; dated pictures of the old and new openings, including work that is now hidden; and a short list of unfinished items with a person and due date beside each. Save the HVAC startup record with those files. It answers whether the equipment was put into service; it does not document how an old roof opening was closed.
If the crew could not see the roof beneath the old unit until lift day, write down who will assess it once exposed and who can approve a change. Our roof inspection limits checklist can help you keep those unknowns visible.
Planning a rooftop AC change in McAllen or elsewhere in the Rio Grande Valley? Request a commercial roof inspection from Marva Roofing and bring the mechanical proposal. Start with the drawing, even if the lift date is still up in the air.
