Your Thermostat During Tear-Off: What Each Roofer Should Say

On tear-off day the roof is open to the sky, and whatever your house does to keep air moving is about to be tested. Your thermostat, your furnace or air handler, and the return vents in the ceiling all pull from the same air that is now carrying shingle grit, nail dust and attic heat. Every roofer will tell you the crew will be careful. Few will tell you what the house will do while the roof is off, and that is the detail worth pulling out before you sign.

What happens to the house while the roof is open

In St. Louis the attic can run very hot in July and August, because the sun works on the deck for hours after the shingles are gone and the deck is not yet covered. A tear-off in summer can leave the attic hotter than it was with shingles on, since the old roofing that held some heat back is also off during the stripping. In winter the problem is the opposite: an open attic admits cold air, and the ductwork that runs through it can lose heat quickly on a freezing morning. Either way, the air handler may keep running and pull attic air into the living space through every return.

Dust is the second problem. Tear-off grit is fine, and it rides on air. A return vent with no cover can pull it into the filter and then into the blower, and a filter loaded with granules and dust can strain the system within a day or two. The crew will not know your system unless you tell them, and it is easy to assume that someone else has already thought about it.

Roofer comparison

When you put two proposals side by side, look for three things: whether the roofer names the thermostat at all, whether the plan covers the return vents, and who decides when the system is shut off. Do not look for a lot of words. A one-line answer that names the actual step is worth more than a page that says the crew will protect the property.

Ask each roofer the same three questions and write down the answers in the order you hear them. A roofer who says the crew will cover the returns, turn the thermostat to off during open-roof hours, and call you before restarting the system has given you a plan you can check. A roofer who says the crew will take care of it has given you a sentence, and you have no way to hold them to it on the day.

Watch for disagreement between proposals. If one roofer's quote includes covering the returns and another's does not, the lower bid may simply have left that step out, not saved you money on it. Compare the steps, not only the totals.

What it costs

Turning a thermostat down or off costs nothing. Covering return vents with plastic sheet and tape costs very little in material, and many roofers can do it with supplies already on the truck. The cost question is who pays for anything beyond that: a technician to shut down or isolate the air handler, a filter change at the end of the job, or a duct cleaning if dust reached the ductwork. Those are not roofing line items in most proposals, so they are easy to miss.

Ask whether the proposal includes a filter change after the tear-off and before the system runs normally again. A new filter is a small charge, but it is still a charge, and the roofer may consider it part of your home maintenance. Get the answer in writing, with the amount if there is one. If the roofer says there is no charge, ask whether that covers the filter as well.

If the air handler sits in a hot attic, ask whether the roofer expects a service call from your HVAC company. That is a separate arrangement between you and the HVAC company, and you will want to book it before the tear-off date rather than during it.

What to ask

• Will the air handler keep running during tear-off, or will the crew ask you to shut it off, and for how many hours each day?
• Will every return vent be covered before the first shingle is pulled, and who removes the covers at the end of each day?
• Who decides when the system goes back on, and will the crew call you first?
• Is a filter change after the job included, and if not, what does it cost?
• If dust reaches the ductwork, who pays for the cleaning, and is that written in the proposal?
• If the thermostat must go to off in summer, what temperature will the house reach overnight, and who is responsible for checking it?

Put the answers in the proposal itself. A verbal promise about the thermostat is easy to forget by the second day of work. Ask the roofer to add a line that names the return covers, the shutdown window, and the restart call, so the plan sits next to the shingles and the flashing where you can read it.

Why this belongs on the schedule

The thermostat step matters on the first day, the last day, and the quiet hours in between. Tear-off often runs a day or two for a house of ordinary size, but the open roof can stay exposed through a weather delay, and that is when a cold snap or a hot afternoon matters most. Put the thermostat step on the same calendar as the material delivery and the dumpster drop, so every day has a named action.

If you have questions about your own house, call the Keys Roofing office at (314) 220-2333 and ask for the written plan before you choose a roofer. Bring the thermostat model, the location of the air handler, and a rough count of how many return vents your house has. A written answer from the start is much easier to hold a crew to than a sentence said at the door.