The day of installation of your new roof is a busy one with a lot of moving parts.
The Production/Project Manager should be there before the crew, at the time agreed upon. The Production/Project Manager should knock, let you know that things are on schedule, or if there are any minor delays, and just confirm everything with you that is relevant.
The crew will unload and stage equipment. Hopefully in an organized manner.
The crew will set up protection for your yard, landscaping and home.
If a dumpster is being delivered, this should arrive soon.
The crew will quickly get on the roof and start removing the old roofing materials.
The old roofing material will be handled in a variety of ways. Logistically, sometimes old material is thrown down to a tarp, and then hauled to the dumpster. Sometims it is thrown directly from the roof to the dumpster. It is worth having a conversation with the Roofing Company to find out how this aspect is handled.
As the old roofing materials are removed, each area of the roofing sheating will be exposed, and able to be analyzed. The better the analysis beforehand, the less surprises you might find at this point. If, for instance, a replacement of all roof sheathing was planned, then removal of the old decking would be an immediate part of the process.
There are way too many variables here, including how different companies formulate their processes, to know what EXACTLY will be done. The more transparent and forthcoming a particular company is, the more information you will have ahead of time.
For purposes of this discussion, assume all the old roofing material is removed, leaving only the old roof sheathing / decking.
Next we will consider the roof at this stage.
NEXT: Old Roof Removed