difference between new roof and replacement 13

https://newconstructionroofingcentral.brightpathdigest.com/posts/why-new-construction-roofing-demands-a-different-approach-in-austin

A new roof is installed on a completely bare deck, often during new construction or after full tear-off, while a replacement involves layering fresh shingles over existing ones or swapping damaged sections without stripping everything to the sheathing.